` using the stored title.","help":{"concept":"A focused test can verify that a subclass correctly receives shared behavior from its base class.","hint_1":"The shared method should return `Item: <title>` using the stored title.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n pass\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n","starterFiles":{"main_py":{"content":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n pass\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n"}},"solutionCode":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Item: {self.title}\"\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n","solutionFiles":{"main_py":{"content":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Item: {self.title}\"\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n"}}},"practice-test-polymorphic-sounds":{"title":"Make a polymorphic collection test pass","prompt":"Complete `collect_sounds(animals)` so it calls `speak()` on every object and returns the resulting list. The provided `Cat` and `Dog` classes override `speak()`. Keep the assertion and final `tests passed` output.","hint":"Loop through the mixed objects and append `animal.speak()` for each one.","help":{"concept":"A polymorphism test checks common behavior through the shared method name instead of branching on each concrete class type.","hint_1":"Loop through the mixed objects and append `animal.speak()` for each one.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n # append each object's speak() result\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n","starterFiles":{"main_py":{"content":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n # append each object's speak() result\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n"}},"solutionCode":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n for animal in animals:\n sounds.append(animal.speak())\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n","solutionFiles":{"main_py":{"content":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n for animal in animals:\n sounds.append(animal.speak())\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n"}}}}},"testing-object-state":{"label":"Testing Object State","summary":"Write executable `assert` tests that prove starting state, rejected state changes, and repeated transitions on real objects.","cards":{"sketch0":{"title":"Assert state before and after a method call"},"sketch1":{"title":"Test both valid and rejected state"},"sketch2":{"title":"Test a sequence on the same object"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_testing_object_state_sketch0":{"title":"Write a before-and-after Book state test","prompt":"`models/book.py` is already complete. In `tests/check_book.py`, use the existing `book` object to write an assertion that it starts available, call `book.checkout()`, then write an assertion that the same object's `available` state is false. Leave the model file unchanged. The test script must still finish by printing `book state tests passed`.","hint":"Use `assert` for both observable states; the method call belongs between those two claims.","help":{"concept":"A state-change test proves the object's state before and after the mutating method.","hint_1":"Check `book.available` before `checkout()`.","hint_2":"Check the same attribute again after `checkout()`."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\n# Assert that the new book starts available.\n# Call checkout() on this same book.\n# Assert that the same book is now unavailable.\n\nprint(\"book state tests passed\")\n","starterFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n"},"tests_check_book_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\n# Assert that the new book starts available.\n# Call checkout() on this same book.\n# Assert that the same book is now unavailable.\n\nprint(\"book state tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\nassert book.available is True\nbook.checkout()\nassert book.available is False\n\nprint(\"book state tests passed\")\n","checks":{"0":{"message":"Keep the Book class defined in models/book.py."},"1":{"message":"Book should still be constructible with a title."},"2":{"message":"A Book instance should have title and available attributes."},"3":{"message":"A new book should start available, then become unavailable after checkout()."}},"solutionFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n"},"tests_check_book_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\nassert book.available is True\nbook.checkout()\nassert book.available is False\n\nprint(\"book state tests passed\")\n"}},"expectedOutput":"book state tests passed","sourceChecks":{"0":{"message":"Use the same Book object for a starting-state assertion, `checkout()`, and an updated-state assertion."}}},"try_testing_object_state_sketch1":{"title":"Test both sides of a validation rule","prompt":"`models/task.py` is already complete. In `tests/check_task.py`, write one assertion proving the existing `normal_task` keeps priority `2`, and another proving the existing `invalid_task` normalizes priority `-5` to `0`. Leave the model unchanged. Keep the final `task validation tests passed` print.","hint":"A validation test set needs one accepted input and one rejected or corrected input.","help":{"concept":"Testing both branches distinguishes the validation rule from a constructor that simply stores every input unchanged.","hint_1":"The normal task should keep priority 2.","hint_2":"The invalid task should expose priority 0."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\n# Assert that the valid priority stays 2.\n# Assert that the negative priority becomes 0.\n\nprint(\"task validation tests passed\")\n","starterFiles":{"models_task_py":{"content":"class Task:\n def __init__(self, name, priority):\n self.name = name\n self.priority = priority if priority >= 0 else 0\n"},"tests_check_task_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\n# Assert that the valid priority stays 2.\n# Assert that the negative priority becomes 0.\n\nprint(\"task validation tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\nassert normal_task.priority == 2\nassert invalid_task.priority == 0\n\nprint(\"task validation tests passed\")\n","checks":{"0":{"message":"Keep the Task class defined in models/task.py."},"1":{"message":"A Task instance should store name and priority."},"2":{"message":"A normal priority should be stored unchanged."},"3":{"message":"A negative priority should be corrected to 0."}},"solutionFiles":{"models_task_py":{"content":"class Task:\n def __init__(self, name, priority):\n self.name = name\n self.priority = priority if priority >= 0 else 0\n"},"tests_check_task_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\nassert normal_task.priority == 2\nassert invalid_task.priority == 0\n\nprint(\"task validation tests passed\")\n"}},"expectedOutput":"task validation tests passed","sourceChecks":{"0":{"message":"Assert that a Task created with priority 2 still has priority 2."},"1":{"message":"Assert that a Task created with priority -5 exposes priority 0."}}},"try_testing_object_state_sketch2":{"title":"Write a repeated state-transition test","prompt":"`models/counter.py` is already complete. In `tests/check_counter.py`, use the existing `counter` object to assert its count is `0`, call `increment()` and assert `1`, then call `increment()` again and assert `2`. Use the same object for the whole sequence. Leave the model unchanged and keep the final `counter sequence tests passed` print.","hint":"The important part is the sequence: 0 → increment → 1 → increment → 2 on one instance.","help":{"concept":"A repeated-transition test catches bugs that only appear after the same object changes state more than once.","hint_1":"Start with an assertion before any method call.","hint_2":"Assert again after each increment on the same counter."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\n# Assert count starts at 0.\n# Increment the same counter and assert count is 1.\n# Increment the same counter again and assert count is 2.\n\nprint(\"counter sequence tests passed\")\n","starterFiles":{"models_counter_py":{"content":"class Counter:\n def __init__(self):\n self.count = 0\n\n def increment(self):\n self.count += 1\n"},"tests_check_counter_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\n# Assert count starts at 0.\n# Increment the same counter and assert count is 1.\n# Increment the same counter again and assert count is 2.\n\nprint(\"counter sequence tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\nassert counter.count == 0\ncounter.increment()\nassert counter.count == 1\ncounter.increment()\nassert counter.count == 2\n\nprint(\"counter sequence tests passed\")\n","checks":{"0":{"message":"Keep the Counter class defined in models/counter.py."},"1":{"message":"A Counter instance should have a count attribute."},"2":{"message":"The count should move from 0 to 1 to 2 across two increment() calls."}},"solutionFiles":{"models_counter_py":{"content":"class Counter:\n def __init__(self):\n self.count = 0\n\n def increment(self):\n self.count += 1\n"},"tests_check_counter_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\nassert counter.count == 0\ncounter.increment()\nassert counter.count == 1\ncounter.increment()\nassert counter.count == 2\n\nprint(\"counter sequence tests passed\")\n"}},"expectedOutput":"counter sequence tests passed","sourceChecks":{"0":{"message":"Use the same Counter object to assert the full 0 → 1 → 2 state sequence."}}}},"practice":{"q-testing-object-state-single-1":{"title":"What should an object-state test check after a mutating method runs?","prompt":"A `checkout()` method is supposed to change a book from available to unavailable. Which test idea best proves that state change happened?","hint":"Look for the choice that checks the attribute after the method call, not just that the method exists.","help":{"concept":"A state-change test should verify the actual attribute value after a mutating method runs, because the goal is to prove behavior, not just structure.","hint_1":"A method can exist and still fail to update the object's data correctly.","hint_2":"Choose the option that inspects the `available` attribute after calling `checkout()`."},"options":{"a":"Create a Book object and check that `available` becomes `False` after calling `checkout()`","b":"Only check that the `Book` class has a `checkout` method name","c":"Print the object once and assume the method worked","d":"Check only the book title because constructors are more important than methods"}},"q-testing-object-state-multi-1":{"title":"Choose the strongest constructor validation checks","prompt":"A `Task` constructor should keep positive priorities unchanged and replace negative priorities with `0`. Which assertions belong in a good test set? Choose all that apply.","hint":"Include one check for valid input and one for invalid input.","help":{"concept":"Good validation coverage includes both the normal path and the edge-case path so the constructor rule is tested from more than one angle.","hint_1":"One correct option should confirm that a positive priority stays the same.","hint_2":"Another correct option should confirm that a negative priority does not remain negative after construction."},"options":{"a":"`Task(\"Email\", 2).priority == 2`","b":"`Task(\"Broken\", -5).priority == 0`","c":"`Task(\"Email\", 2).name == 2`","d":"`Task(\"Broken\", -5).priority == -5`"}},"q-testing-object-state-fill-1":{"title":"Complete an assert for starting state","prompt":"Fill in the missing value so the assertion checks that a new counter starts at zero.","hint":"A new `Counter` object should begin with no increments applied.","help":{"concept":"Starting-state assertions verify what the constructor sets before any methods change the object.","hint_1":"The `count` attribute should match the constructor's initial value.","hint_2":"Choose the numeric value that represents an untouched counter."},"template":"assert counter.count == [blank1]","choices":["0","1","False","None"]},"q-testing-object-state-drag-1":{"title":"Order a before-and-after state test","prompt":"Put these testing steps in the best order for checking a method that changes object state.","hint":"Read each piece and arrange them in the order the statement should be understood.","help":{"concept":"The pieces should form a valid statement in a logical order.","hint_1":"Start with the piece that introduces the idea or action.","hint_2":"Place dependent pieces after the part they describe or complete."},"tokens":{"t1":"Assert the starting attribute value","t2":"Create the object","t3":"Call the state-changing method","t4":"Assert the updated attribute value"}},"q-testing-object-state-multi-2":{"title":"Spot useful object-state edge cases","prompt":"You are testing a `Counter` object with an `increment()` method. Which checks help prove repeated state changes work correctly? Choose all that apply.","hint":"Think about what happens before any increments and after more than one increment.","help":{"concept":"Repeated state-change tests are stronger when they verify the initial state and multiple successive updates on the same object.","hint_1":"One correct option should check the starting count before any method calls.","hint_2":"Another correct option should check the count after the method has been called more than once on the same instance."},"options":{"a":"Assert that a new counter starts at `0`","b":"Assert that the same counter reaches `2` after two `increment()` calls","c":"Only check that `increment` is spelled correctly","d":"Create two separate counters and ignore their `count` values"}},"q-testing-object-state-fill-2":{"title":"Complete an assert after a checkout","prompt":"Fill in the missing value so the assertion checks the book's state after `checkout()` has already run.","hint":"After checkout, the book should no longer be available.","help":{"concept":"After-method assertions should match the new stored state, not the original constructor value.","hint_1":"The `available` attribute should switch away from its starting value.","hint_2":"Choose the boolean value that represents an unavailable book."},"template":"assert book.available is [blank1]","choices":["True","False","0","Lesson notes panel"]},"ci-testing-object-state-debug-book-return":{"title":"Fix a broken return method after state changes","prompt":"A checkout service uses `Book.checkout()` and `Book.return_book()`. Right now, returning a book does not restore availability. Fix `models/book.py` so the object's state changes correctly. Do not change the test file. When you click Run, the output panel should show that the tests passed.","hint":"Read the task \"Fix a broken return method after state changes\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Fix a broken return method after state changes\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = False","starterFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = False"},"tests_check_book_return_py":{"content":"from models.book import Book\n\nbook = Book(\"Dune\")\nassert book.available is True\nbook.checkout()\nassert book.available is False\nbook.return_book()\nassert book.available is True\n\nprint(\"book return tests passed\")"}},"solutionFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = True"},"tests_check_book_return_py":{"content":"from models.book import Book\n\nbook = Book(\"Dune\")\nassert book.available is True\nbook.checkout()\nassert book.available is False\nbook.return_book()\nassert book.available is True\n\nprint(\"book return tests passed\")"}},"solutionCode":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = True","checks":{"0":{"message":"Keep the Book class defined."},"1":{"message":"Book instances should still store title and available."},"2":{"message":"A new Book should start available."},"3":{"message":"checkout() should mark the book unavailable."},"4":{"message":"return_book() should make a checked-out book available again."}}},"ci-testing-object-state-fix-wallet-validation":{"title":"Fix wallet validation so balance never starts negative","prompt":"A budgeting app has a `Wallet` class in `models/wallet.py`. The constructor should store the given balance when it is zero or more, but negative starting balances should become `0`. The current code stores negative values by mistake. Fix the class so the provided tests in `tests/check_wallet.py` pass when you click Run.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = starting_balance","starterFiles":{"models_wallet_py":{"content":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = starting_balance"},"tests_check_wallet_py":{"content":"from models.wallet import Wallet\n\nwallet_a = Wallet(\"Ava\", 25)\nassert wallet_a.balance == 25\n\nwallet_b = Wallet(\"Ben\", -10)\nassert wallet_b.balance == 0\n\nprint(\"wallet validation tests passed\")"}},"solutionFiles":{"models_wallet_py":{"content":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = max(0, starting_balance)"},"tests_check_wallet_py":{"content":"from models.wallet import Wallet\n\nwallet_a = Wallet(\"Ava\", 25)\nassert wallet_a.balance == 25\n\nwallet_b = Wallet(\"Ben\", -10)\nassert wallet_b.balance == 0\n\nprint(\"wallet validation tests passed\")"}},"solutionCode":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = max(0, starting_balance)","checks":{"0":{"message":"Keep the Wallet class defined."},"1":{"message":"Wallet instances should store owner and balance."},"2":{"message":"A valid starting balance should stay unchanged."},"3":{"message":"A negative starting balance should be corrected to 0."}}},"ci-testing-object-state-fix-scoreboard-add-points":{"title":"Fix a method that updates score incorrectly","prompt":"A game app has a `Scoreboard` class in `models/scoreboard.py`. The `add_points()` method should increase the current score by the amount passed in. Right now it resets the score instead. Fix the class so the tests in `tests/check_scoreboard.py` pass.","hint":"Read the task \"Fix a method that updates score incorrectly\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Fix a method that updates score incorrectly\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score = points","starterFiles":{"models_scoreboard_py":{"content":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score = points"},"tests_check_scoreboard_py":{"content":"from models.scoreboard import Scoreboard\n\nboard = Scoreboard()\nassert board.score == 0\nboard.add_points(5)\nassert board.score == 5\nboard.add_points(3)\nassert board.score == 8\n\nprint(\"scoreboard state tests passed\")"}},"solutionFiles":{"models_scoreboard_py":{"content":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score += points"},"tests_check_scoreboard_py":{"content":"from models.scoreboard import Scoreboard\n\nboard = Scoreboard()\nassert board.score == 0\nboard.add_points(5)\nassert board.score == 5\nboard.add_points(3)\nassert board.score == 8\n\nprint(\"scoreboard state tests passed\")"}},"solutionCode":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score += points","checks":{"0":{"message":"Keep the Scoreboard class defined."},"1":{"message":"Scoreboard instances should have a score attribute."},"2":{"message":"A new Scoreboard should start at 0."},"3":{"message":"After add_points(5), the score should be 5."},"4":{"message":"Points should accumulate, so 5 then 3 should produce 8."}}}}}},"python-11-oop-capstone-project":{"capstone-domain-model":{"label":"Capstone Domain Model","summary":"Build the task objects that carry the tracker domain before adding storage or reports.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_domain_model_sketch0":{"title":"Create the shared BaseTask model","prompt":"In `models/base_task.py`, implement `BaseTask` with `title`, validated `priority`, and `completed` state. New tasks start incomplete. `mark_done()` sets completed to True, `is_open()` returns the opposite, and `summary()` raises NotImplementedError. The supplied main.py marks one task done and prints its state.","hint":"Validate before storing the fields, then mutate only `self.completed` in mark_done().","help":{"concept":"The base class owns shared state and behavior while leaving the concrete summary format to subclasses.","hint_1":"Validate before storing the fields, then mutate only `self.completed` in mark_done().","hint_2":"Inspect the requested file and account for each requirement before running the workspace."},"starterCode":"# Run this provided BaseTask state demo.\nfrom models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n","starterFiles":{"main_py":{"content":"# Run this provided BaseTask state demo.\nfrom models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n"},"models_base_task_py":{"content":"class BaseTask:\n def __init__(self, title, priority=\"medium\", completed=False):\n # TODO: validate and store title, priority, and completed.\n pass\n\n def mark_done(self):\n # TODO: set completed to True and return it.\n pass\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"}},"solutionFiles":{"main_py":{"content":"from models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"}},"solutionCode":"from models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n","checks":{"0":{"message":"Store the shared task attributes."},"1":{"message":"A marked-done task should no longer be open."},"2":{"message":"Print the title, priority, and final completed state."}},"expectedOutput":"Draft roadmap\nhigh\nTrue"}}}},"capstone-scope-and-architecture":{"label":"Capstone Scope and Architecture","summary":"Plan the Smart Task Tracker workspace so models, services, data, and main.py each have a clear job.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_scope_and_architecture_sketch0":{"title":"Plan one clean capstone workspace","prompt":"Complete `reports/summary.py` so build_summary(tasks) returns one summary line per task. Keep the task hierarchy in models and the runner in main.py; do not copy model classes into main.py.","hint":"Join task.summary() results with newline characters.","help":{"concept":"A clean architecture gives models, reports, storage, services, and the runner separate responsibilities.","hint_1":"Join task.summary() results with newline characters.","hint_2":"Review the file path, class or function name, and output requirements together."},"starterCode":"# Run this provided architecture snapshot.\nfrom models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n","starterFiles":{"main_py":{"content":"# Run this provided architecture snapshot.\nfrom models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n"},"models_base_task_py":{"content":"# Starter guidance: Plan one clean capstone workspace. Follow the prompt and edit the requested code below.\nclass BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"# Starter guidance: Plan one clean capstone workspace. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"# Starter guidance: Plan one clean capstone workspace. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"# Keep this package marker so imports work.\nfrom models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"def build_summary(tasks):\n # TODO: return one summary line per task.\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"from models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"from models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"from models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"def build_summary(tasks):\n return \"\\n\".join(task.summary() for task in tasks)\n"}},"solutionCode":"from models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n","checks":{"0":{"message":"Return both task summaries from the report module."}},"expectedOutput":"BUG: Fix login redirect | priority=high | severity=critical | done=False\nFEATURE: Add dark mode | priority=medium | points=3 | done=False"}}}},"capstone-storage-and-reports":{"label":"Capstone Storage and Reports","summary":"Load task data into objects and turn those objects into useful report output.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_storage_and_reports_sketch0":{"title":"Load task objects from CSV","prompt":"Complete storage/task_storage.py so load_tasks(path) reads data/tasks.csv and returns the correct task subclasses in file order. The supplied runner prints the count and first title.","hint":"Use DictReader, convert completed to bool, and convert feature detail to int.","help":{"concept":"Storage code translates serialized rows into validated domain objects.","hint_1":"Use DictReader, convert completed to bool, and convert feature detail to int.","hint_2":"Use the requested file boundary as part of the solution contract."},"starterCode":"# Run this provided storage smoke test.\nfrom storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n","starterFiles":{"main_py":{"content":"# Run this provided storage smoke test.\nfrom storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n"},"models_base_task_py":{"content":"# Starter guidance: Load task objects from CSV. Follow the prompt and edit the requested code below.\nclass BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"# Starter guidance: Load task objects from CSV. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"# Starter guidance: Load task objects from CSV. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"# Keep this package marker so imports work.\nfrom models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"},"storage_task_storage_py":{"content":"import csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n # TODO: parse each CSV row into the matching task subclass.\n pass\n"}},"solutionFiles":{"main_py":{"content":"from storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"from models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"from models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"from models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"},"storage_task_storage_py":{"content":"import csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n tasks = []\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n completed = row[\"completed\"].lower() == \"true\"\n if row[\"kind\"] == \"bug\":\n task = BugTask(row[\"title\"], row[\"priority\"], row[\"detail\"], completed)\n elif row[\"kind\"] == \"feature\":\n task = FeatureTask(row[\"title\"], row[\"priority\"], int(row[\"detail\"]), completed)\n else:\n raise ValueError(f\"unknown task kind: {row['kind']}\")\n tasks.append(task)\n return tasks\n"}},"solutionCode":"from storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n","checks":{"0":{"message":"Load three tasks and preserve the first title."}},"expectedOutput":"3\nFix login redirect"}}}},"capstone-tests-and-polish":{"label":"Capstone Tests and Polish","summary":"Add assertions, final output polish, and README handoff notes so the capstone feels complete.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_tests_and_polish_sketch0":{"title":"Add focused model checks","prompt":"Complete main.py with assertions that a new BugTask is open and a FeatureTask estimate of 0 becomes 1. Print `model checks passed` after both assertions.","hint":"Create both objects, assert their state, then print confirmation.","help":{"concept":"Focused tests prove validation and starting state before testing larger workflows.","hint_1":"Create both objects, assert their state, then print confirmation.","hint_2":"Use the requested file boundary as part of the solution contract."},"starterCode":"# TODO: create the two tasks, add the required assertions, then print confirmation.\n","starterFiles":{"main_py":{"content":"# TODO: create the two tasks, add the required assertions, then print confirmation.\n"},"models_base_task_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nclass BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"# Keep this package marker so imports work.\nfrom models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\ndef build_summary(tasks):\n lines = [\"SMART TASK TRACKER\"]\n lines.extend(task.summary() for task in tasks)\n open_count = sum(task.is_open() for task in tasks)\n lines.append(f\"OPEN: {open_count} | DONE: {len(tasks) - open_count}\")\n return \"\\n\".join(lines)\n"},"storage_task_storage_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nimport csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n tasks = []\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n completed = row[\"completed\"].lower() == \"true\"\n if row[\"kind\"] == \"bug\":\n task = BugTask(row[\"title\"], row[\"priority\"], row[\"detail\"], completed)\n elif row[\"kind\"] == \"feature\":\n task = FeatureTask(row[\"title\"], row[\"priority\"], int(row[\"detail\"]), completed)\n else:\n raise ValueError(f\"unknown task kind: {row['kind']}\")\n tasks.append(task)\n return tasks\n"},"services_tracker_service_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nclass TrackerService:\n def __init__(self, tasks=None):\n self.tasks = list(tasks or [])\n\n def add_task(self, task):\n self.tasks.append(task)\n return task\n\n def mark_done(self, title):\n for task in self.tasks:\n if task.title == title:\n task.mark_done()\n return True\n return False\n\n def count_open_tasks(self):\n return sum(task.is_open() for task in self.tasks)\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"}},"solutionFiles":{"main_py":{"content":"from models import BugTask, FeatureTask\n\nbug = BugTask(\"Fix login\", \"high\", \"critical\")\nfeature = FeatureTask(\"Polish UI\", \"low\", 0)\nassert bug.is_open() is True\nassert feature.estimate_points == 1\nprint(\"model checks passed\")\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"from models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"from models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"from models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"def build_summary(tasks):\n lines = [\"SMART TASK TRACKER\"]\n lines.extend(task.summary() for task in tasks)\n open_count = sum(task.is_open() for task in tasks)\n lines.append(f\"OPEN: {open_count} | DONE: {len(tasks) - open_count}\")\n return \"\\n\".join(lines)\n"},"storage_task_storage_py":{"content":"import csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n tasks = []\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n completed = row[\"completed\"].lower() == \"true\"\n if row[\"kind\"] == \"bug\":\n task = BugTask(row[\"title\"], row[\"priority\"], row[\"detail\"], completed)\n elif row[\"kind\"] == \"feature\":\n task = FeatureTask(row[\"title\"], row[\"priority\"], int(row[\"detail\"]), completed)\n else:\n raise ValueError(f\"unknown task kind: {row['kind']}\")\n tasks.append(task)\n return tasks\n"},"services_tracker_service_py":{"content":"class TrackerService:\n def __init__(self, tasks=None):\n self.tasks = list(tasks or [])\n\n def add_task(self, task):\n self.tasks.append(task)\n return task\n\n def mark_done(self, title):\n for task in self.tasks:\n if task.title == title:\n task.mark_done()\n return True\n return False\n\n def count_open_tasks(self):\n return sum(task.is_open() for task in self.tasks)\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"}},"solutionCode":"from models import BugTask, FeatureTask\n\nbug = BugTask(\"Fix login\", \"high\", \"critical\")\nfeature = FeatureTask(\"Polish UI\", \"low\", 0)\nassert bug.is_open() is True\nassert feature.estimate_points == 1\nprint(\"model checks passed\")\n","checks":{"0":{"message":"Run both model assertions before confirmation."}},"expectedOutput":"model checks passed"}}}},"module-11-final-oop-capstone":{"label":"Neighborhood Pantry Request Coordinator","summary":"Build a pantry request coordinator that turns saved food and hygiene requests into validated objects, managed state, and a clear daily report.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Neighborhood Pantry Request Coordinator"}},"projectSteps":{"try_module_11_final_oop_capstone_sketch0":{"title":"Milestone 1: Build the abstract request foundation"},"project_pantry_request_step_2_models":{"title":"Milestone 2: Add HygieneRequest and prove polymorphism"},"project_pantry_request_step_3_service":{"title":"Milestone 3: Give PantryService ownership of the queue"},"project_pantry_request_step_4_storage":{"title":"Milestone 4: Load request objects from CSV"},"project_pantry_request_step_5_reports_tests":{"title":"Milestone 5: Add the report and regression tests"},"project_pantry_request_step_6_final_handoff":{"title":"Milestone 6: Deliver the final pantry coordinator"}},"finalCapstone":{"steps":{"try_module_11_final_oop_capstone_sketch0":{"title":"Milestone 1: Build the abstract request foundation","prompt":"Build the shared pantry-request foundation. In `models/pantry_request.py`, make `PantryRequest` inherit from `ABC`; keep the allowed priorities `low`, `medium`, and `high`; validate `household` and `priority` through properties; store fulfillment state privately; expose a read-only `fulfilled` property; implement `mark_fulfilled()` and `is_open()`; and make `category(self)` and `details(self)` abstract methods. `summary()` must remain concrete and build its text from those public members. In `models/food_request.py`, keep `FoodRequest(PantryRequest)`, call `super().__init__`, validate a nonblank `food_type`, return `FOOD` from `category()`, and return `food=<value>` from `details()`. Finally, complete `main.py` so it creates a FoodRequest from the provided inputs and prints its summary. Do not implement HygieneRequest yet.","hint":"Retrieve the validated-property pattern from Module 8 and the ABC/inheritance patterns from Module 9.","help":{"concept":"The abstract parent owns shared validation/state while a concrete child supplies request-specific behavior.","hint_1":"Use `ABC` plus `@abstractmethod` on `category()` and `details()`.","hint_2":"Use `super().__init__(household, priority, fulfilled)` in FoodRequest."},"starterCode":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\n# Create the FoodRequest and print its summary.\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\n# Create the FoodRequest and print its summary.\n"},"models_pantry_request_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass PantryRequest:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, household, priority=\"medium\", fulfilled=False):\n # TODO: route household and priority through validated properties.\n # TODO: store fulfillment state privately.\n pass\n\n # TODO: add validated household and priority properties.\n\n @property\n def fulfilled(self):\n # TODO: expose the private fulfillment state.\n pass\n\n def mark_fulfilled(self):\n # TODO: update state and return the new fulfilled value.\n pass\n\n def is_open(self):\n # TODO: return whether the request is still open.\n pass\n\n # TODO: make category() and details() abstract methods.\n\n def summary(self):\n # TODO: combine the shared state with category() and details().\n pass\n"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n # TODO: reuse PantryRequest setup and validate food_type.\n pass\n\n # TODO: implement category() and details().\n"},"models_hygiene_request_py":{"content":"# HygieneRequest is added in the next milestone.\n"},"models___init___py":{"content":"# TODO: export PantryRequest and FoodRequest.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n"},"models_pantry_request_py":{"content":"$8d"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"# HygieneRequest is added in the next milestone.\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\"]\n"}},"solutionCode":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n","checks":{"0":{"message":"Create the `PantryRequest` class in `models/pantry_request.py`."},"1":{"message":"`FoodRequest.summary()` must return the Rivera family line shown in the expected example."},"2":{"message":"`main.py` must print the completed food-request summary."},"3":{"message":"Import both `ABC` and `abstractmethod` from `abc` in `models/pantry_request.py`."},"4":{"message":"Declare the base class as `class PantryRequest(ABC):`."},"5":{"message":"Mark the subclass contract with `@abstractmethod` in `models/pantry_request.py`."},"6":{"message":"Use properties to protect the request state and validation rules."},"7":{"message":"Declare `FoodRequest` as a subclass of `PantryRequest` in `models/food_request.py`."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"FOOD: Rivera family | priority=high | food=produce | fulfilled=False","sourceChecks":{"0":{"message":"Make `PantryRequest` inherit from `ABC`."},"1":{"message":"Use a `household` property and setter for validated state."},"2":{"message":"Use a `priority` property and setter for validated state."},"3":{"message":"Make both `category(self)` and `details(self)` abstract methods."},"4":{"message":"Keep FoodRequest inheriting from PantryRequest and reuse the parent constructor with `super()`."}}},"project_pantry_request_step_2_models":{"title":"Milestone 2: Add HygieneRequest and prove polymorphism","prompt":"Continue from the exact Milestone 1 workspace. Implement `HygieneRequest(PantryRequest)` in `models/hygiene_request.py`. Reuse the parent constructor with `super()`, convert `units` to an integer, reject values below 1, return `HYGIENE` from `category()`, and return `units=<value>` from `details()`. Then update `main.py` to build one FoodRequest and one HygieneRequest from the provided inputs, place them in one `requests` list, and use one `for` loop that calls the current object's shared `summary()` method. Do not branch with `isinstance()`, `type()`, `__class__`, or separate food/hygiene print logic. Keep the completed PantryRequest and FoodRequest unchanged.","hint":"The new subclass specializes the same abstract methods; the caller should trust the shared `summary()` interface.","help":{"concept":"This milestone retrieves inheritance, overriding, and branch-free polymorphism in one mixed collection.","hint_1":"Use `super().__init__` in HygieneRequest.","hint_2":"Inside the loop, call only `request.summary()`."},"starterCode":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n"},"models_pantry_request_py":{"content":"$8e"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"# Added in Milestone 2.\n"},"models___init___py":{"content":"# TODO: export PantryRequest, FoodRequest, and HygieneRequest.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n"},"models_pantry_request_py":{"content":"$8f"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"}},"solutionCode":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n","checks":{"0":{"message":"Preserve the correct `FoodRequest.summary()` behavior from the previous milestone."},"1":{"message":"`HygieneRequest.summary()` must return the Chen family line shown in the expected example."},"2":{"message":"`main.py` must print both request summaries."},"3":{"message":"Declare `HygieneRequest` as a subclass of `PantryRequest`."},"4":{"message":"Use a `for` loop in `main.py` to process the mixed request list."},"5":{"message":"Call `request.summary()` inside the loop instead of branching by request type."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"FOOD: Rivera family | priority=high | food=produce | fulfilled=False\nHYGIENE: Chen family | priority=medium | units=3 | fulfilled=False","sourceChecks":{"0":{"message":"Keep HygieneRequest inheriting from PantryRequest and reuse the shared constructor with `super()`."},"1":{"message":"Implement the required `category()` and `details()` methods."},"2":{"message":"Use one branch-free loop over `requests` and call the shared `summary()` method."}}},"project_pantry_request_step_3_service":{"title":"Milestone 3: Give PantryService ownership of the queue","prompt":"Continue from the exact Milestone 2 workspace. Implement `PantryService` in `services/pantry_service.py`. Store the mutable collection privately in `self._requests`; accept an optional starting collection and add each item through `add_request()`; expose a read-only `requests` property that returns a tuple; reject non-PantryRequest values in `add_request()`; implement `mark_fulfilled(household)` by calling the matching request's `mark_fulfilled()` method; count open requests through `request.is_open()`; and build summary lines through `request.summary()`. Update `main.py` to create the two request objects, create the service, fulfill the household supplied by input, print the service's summary lines, and print the open count. `main.py` must not reach into `_requests` or duplicate model state logic.","hint":"The service owns collection coordination; each request object still owns its own state and summary behavior.","help":{"concept":"Encapsulation protects the mutable collection while service methods delegate behavior to the model objects.","hint_1":"Return `tuple(self._requests)` from the property.","hint_2":"Call `request.mark_fulfilled()`, `request.is_open()`, and `request.summary()` rather than changing model fields."},"starterCode":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n"},"models_pantry_request_py":{"content":"$90"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"# Added in Milestone 3.\n"},"services___init___py":{"content":"# Package marker for imports.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$91"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"}},"solutionCode":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n","checks":{"0":{"message":"Create the `PantryService` class in `services/pantry_service.py`."},"1":{"message":"A new empty `PantryService` must report `0` open requests."},"2":{"message":"`main.py` must print the two summaries and the open-request count."},"3":{"message":"Store the mutable collection in `self._requests` inside `PantryService`."},"4":{"message":"Expose the collection through a read-only property instead of returning the internal list directly."},"5":{"message":"Delegate fulfillment to `request.mark_fulfilled()` instead of changing model state from the service."},"6":{"message":"Build service summary lines by calling `request.summary()` polymorphically."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"FOOD: Rivera family | priority=high | food=produce | fulfilled=True\nHYGIENE: Chen family | priority=medium | units=3 | fulfilled=False\nOPEN: 1","sourceChecks":{"0":{"message":"Keep the mutable list private and expose a tuple through a read-only property."},"1":{"message":"`add_request()` should accept only PantryRequest objects and append the validated object."},"2":{"message":"Delegate state, open-count, and summary behavior to request objects instead of duplicating it in the service."},"3":{"message":"Keep main.py outside the service's private `_requests` state."}}},"project_pantry_request_step_4_storage":{"title":"Milestone 4: Load request objects from CSV","prompt":"Continue from the exact Milestone 3 workspace. Implement `storage/request_storage.py`. `parse_fulfilled(value)` must treat `true`, `1`, and `yes` as fulfilled regardless of surrounding spaces or letter case. `load_requests(path)` must use `csv.DictReader`, construct FoodRequest or HygieneRequest from the `type` column, convert hygiene units to an integer, preserve priority and fulfilled state through the real constructors, and raise `ValueError` for an unknown type. The supplied `tests/check_storage.py` is the executable boundary test for this milestone; do not rewrite the models or service to compensate for storage bugs.","hint":"Storage may choose which concrete class to construct; once the object exists, the rest of the application uses the shared OOP interface.","help":{"concept":"A storage adapter translates serialized rows into validated domain objects without duplicating model/report rules.","hint_1":"Use `csv.DictReader` and normalize the `type`/fulfilled text.","hint_2":"Raise ValueError when the type is neither food nor hygiene."},"starterCode":"# Added in Milestone 4.\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$92"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"# Added in Milestone 4.\n"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"tests_check_storage_py":{"content":"# Added in Milestone 4.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$93"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$94"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"tests_check_storage_py":{"content":"$95"}},"solutionCode":"$96","checks":{"0":{"message":"`parse_fulfilled(\"yes\")` must return `True`."},"1":{"message":"`main.py` must print the three requests loaded from the CSV file."},"2":{"message":"Import `FoodRequest` into `storage/request_storage.py` so food rows become food objects."},"3":{"message":"Import `HygieneRequest` into `storage/request_storage.py` so hygiene rows become hygiene objects."},"4":{"message":"Read the CSV with `csv.DictReader`."},"5":{"message":"Print loaded objects through `request.summary()` in `main.py`."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"storage tests passed","sourceChecks":{"0":{"message":"Use Python's `csv` module for the storage adapter."},"1":{"message":"Normalize surrounding spaces/case and recognize true, 1, and yes."},"2":{"message":"Read request rows with `csv.DictReader`."},"3":{"message":"Construct the two concrete request types and reject an unknown type."}}},"project_pantry_request_step_5_reports_tests":{"title":"Milestone 5: Add the report and regression tests","prompt":"Continue from the exact Milestone 4 workspace. Implement `build_summary(requests)` in `reports/summary.py`: start with `NEIGHBORHOOD PANTRY REQUESTS`, append one `request.summary()` line per object, calculate open requests through `request.is_open()`, derive the fulfilled count, and return one newline-separated string. Do not branch on FoodRequest versus HygieneRequest in the report. Then complete `tests/check_requests.py`. Without using `inspect`, prove that PantryRequest cannot be instantiated while abstract; prove blank household and zero-unit validation; test a mixed PantryService; test fulfillment delegation and open count; and assert the full report for that mixed fixture. Keep the provided `run_checks()` function and final script print. Finally, update `main.py` to load the saved CSV requests and print `build_summary(requests)`.","hint":"Prove abstraction by attempting to instantiate the abstract base and catching TypeError; the report itself should use only the shared request interface.","help":{"concept":"Regression tests protect the architecture, while the report remains polymorphic and independent of concrete request types.","hint_1":"Use request.summary() and request.is_open() in the report.","hint_2":"Your tests should exercise validation, mixed objects, service state changes, and the returned report string."},"starterCode":"# Added in Milestone 5.\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$97"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$98"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"# Added in Milestone 5.\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"# Added in Milestone 5.\n"},"tests___init___py":{"content":"# Package marker for imports.\n"},"tests_check_storage_py":{"content":"$99"}},"solutionFiles":{"main_py":{"content":"from reports.summary import build_summary\nfrom storage.request_storage import load_requests\n\nrequests = load_requests(\"data/requests.csv\")\nprint(build_summary(requests))\n"},"models_pantry_request_py":{"content":"$9a"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$9b"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"def build_summary(requests):\n request_list = list(requests)\n lines = [\"NEIGHBORHOOD PANTRY REQUESTS\"]\n\n for request in request_list:\n lines.append(request.summary())\n\n open_count = sum(\n request.is_open()\n for request in request_list\n )\n fulfilled_count = len(request_list) - open_count\n\n lines.append(\n f\"OPEN: {open_count} | FULFILLED: {fulfilled_count}\"\n )\n return \"\\n\".join(lines)\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"$9c"},"tests___init___py":{"content":"# Package marker for imports.\n"},"tests_check_storage_py":{"content":"$9d"}},"solutionCode":"$9e","checks":{"0":{"message":"`main.py` must print the complete report with its heading, request lines, and totals."},"1":{"message":"Build every report row with `request.summary()` so the report remains polymorphic."},"2":{"message":"Calculate open totals with `request.is_open()` instead of reading or duplicating internal state rules."},"3":{"message":"Assert that `PantryRequest` is abstract with `isabstract(PantryRequest)`."},"4":{"message":"Add meaningful assertions in `tests/check_requests.py` for validation and mixed-subclass service behavior."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"request tests passed","sourceChecks":{"0":{"message":"Build the report from `request.summary()` and `request.is_open()` without concrete-type branches."},"1":{"message":"Prove the abstract base cannot be instantiated by catching TypeError."},"2":{"message":"Test both blank-household and zero-unit validation failures."},"3":{"message":"Add meaningful assertions for mixed summaries, fulfillment, open count, and the final report."},"4":{"message":"Keep main.py thin: load request objects and print the report."}}},"project_pantry_request_step_6_final_handoff":{"title":"Milestone 6: Deliver the final pantry coordinator","prompt":"Continue from the Milestone 5 workspace and deliver the application the pantry team will actually run. In `main.py`, create `PantryService(load_requests(\"data/requests.csv\"))`; fulfill the Rivera and Chen requests through `service.mark_fulfilled()`; add a fulfilled `HygieneRequest(\"Davis family\", \"medium\", 2, True)`; print the deterministic `build_summary(service.requests)` report; and then print exactly `PANTRY REQUEST COORDINATOR READY`. Keep the regression files in `tests/`, but do not import test modules into production `main.py`. In `README.md`, explain the responsibilities of models, services, storage, reports, tests, and main.py; mention validated properties, ABC/abstract methods, inheritance/super, overriding, and polymorphism; and include the run command `python main.py`.","hint":"The final runner should wire together production layers only. Regression files protect the project separately.","help":{"concept":"A production entry point orchestrates application code; test modules stay independent so they can verify the application without becoming a runtime dependency.","hint_1":"Load the CSV into PantryService, make the required state changes, then pass `service.requests` to `build_summary()`.","hint_2":"Document each folder's responsibility and the exact `python main.py` run command in README.md."},"starterCode":"from reports.summary import build_summary\nfrom storage.request_storage import load_requests\n\nrequests = load_requests(\"data/requests.csv\")\nprint(build_summary(requests))\n","starterFiles":{"main_py":{"content":"from reports.summary import build_summary\nfrom storage.request_storage import load_requests\n\nrequests = load_requests(\"data/requests.csv\")\nprint(build_summary(requests))\n"},"models_pantry_request_py":{"content":"$9f"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$a0"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"def build_summary(requests):\n request_list = list(requests)\n lines = [\"NEIGHBORHOOD PANTRY REQUESTS\"]\n\n for request in request_list:\n lines.append(request.summary())\n\n open_count = sum(\n request.is_open()\n for request in request_list\n )\n fulfilled_count = len(request_list) - open_count\n\n lines.append(\n f\"OPEN: {open_count} | FULFILLED: {fulfilled_count}\"\n )\n return \"\\n\".join(lines)\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"$a1"},"tests___init___py":{"content":"# Package marker for imports.\n"},"README_md":{"content":"# Neighborhood Pantry Request Coordinator\n\nComplete the final architecture and handoff notes in Milestone 6.\n"},"tests_check_storage_py":{"content":"$a2"}},"solutionFiles":{"main_py":{"content":"from models.hygiene_request import HygieneRequest\nfrom reports.summary import build_summary\nfrom services.pantry_service import PantryService\nfrom storage.request_storage import load_requests\n\nservice = PantryService(load_requests(\"data/requests.csv\"))\nservice.mark_fulfilled(\"Rivera family\")\nservice.mark_fulfilled(\"Chen family\")\nservice.add_request(\n HygieneRequest(\n \"Davis family\",\n \"medium\",\n 2,\n True,\n )\n)\n\nprint(build_summary(service.requests))\nprint(\"PANTRY REQUEST COORDINATOR READY\")\n"},"models_pantry_request_py":{"content":"$a3"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$a4"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"def build_summary(requests):\n request_list = list(requests)\n lines = [\"NEIGHBORHOOD PANTRY REQUESTS\"]\n\n for request in request_list:\n lines.append(request.summary())\n\n open_count = sum(\n request.is_open()\n for request in request_list\n )\n fulfilled_count = len(request_list) - open_count\n\n lines.append(\n f\"OPEN: {open_count} | FULFILLED: {fulfilled_count}\"\n )\n return \"\\n\".join(lines)\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"$a5"},"tests___init___py":{"content":"# Package marker for imports.\n"},"README_md":{"content":"$a6"},"tests_check_storage_py":{"content":"$a7"}},"solutionCode":"from models.hygiene_request import HygieneRequest\nfrom reports.summary import build_summary\nfrom services.pantry_service import PantryService\nfrom storage.request_storage import load_requests\n\nservice = PantryService(load_requests(\"data/requests.csv\"))\nservice.mark_fulfilled(\"Rivera family\")\nservice.mark_fulfilled(\"Chen family\")\nservice.add_request(\n HygieneRequest(\n \"Davis family\",\n \"medium\",\n 2,\n True,\n )\n)\n\nprint(build_summary(service.requests))\nprint(\"PANTRY REQUEST COORDINATOR READY\")\n","checks":{"0":{"message":"`main.py` must print the complete final report and the readiness confirmation."},"1":{"message":"Explain **Abstraction** in `README.md`, including the role of `PantryRequest` as the abstract contract."},"2":{"message":"Explain **Polymorphism** in `README.md`, including how mixed request types share one interface."},"3":{"message":"Include the exact run command `python main.py` in `README.md`."},"4":{"message":"Call `run_checks()` from `main.py` before the final workflow."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"NEIGHBORHOOD PANTRY REQUESTS\nFOOD: Rivera family | priority=high | food=produce | fulfilled=True\nHYGIENE: Chen family | priority=medium | units=3 | fulfilled=True\nHYGIENE: Morgan family | priority=low | units=5 | fulfilled=True\nHYGIENE: Davis family | priority=medium | units=2 | fulfilled=True\nOPEN: 0 | FULFILLED: 4\nPANTRY REQUEST COORDINATOR READY","sourceChecks":{"0":{"message":"Keep production `main.py` independent of test modules, then load the CSV through PantryService, apply the required state changes, print the final report, and print the readiness line."},"1":{"message":"Document the responsibility of every production/test layer."},"2":{"message":"Document the retrieved OOP concepts and the exact run command."}}}}}}},"python-8-object-oriented-foundations":{"class-files-and-instances":{"label":"Class Files and Instances","summary":"Define a minimal class in a model file, import it from `main.py`, and create an instance across that file boundary.","cards":{"sketch0":{"title":"Define the class file"},"sketch1":{"title":"Import and use the class"},"sketch2":{"title":"Keep files clean"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_class_files_and_instances_sketch0":{"title":"Define a minimal Car class","prompt":"In `models/car.py`, define a class named `Car` and put `pass` in its body so the class is valid but intentionally empty. Leave `main.py` unchanged. Do not add a constructor yet.","hint":"The class definition belongs in `models/car.py`. Use `pass` as the placeholder body.","help":{"concept":"`pass` is a placeholder statement. It lets you define a valid class before adding real behavior.","hint_1":"Start the definition with `class Car:`.","hint_2":"Indent `pass` inside the class body."},"starterCode":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet.","starterFiles":{"main_py":{"content":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet."},"models_car_py":{"content":"# Define the Car class shell below.\n"}},"solutionCode":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet.","solutionFiles":{"main_py":{"content":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet."},"models_car_py":{"content":"class Car:\n pass"}},"checks":{"0":{"message":"Define a Car class in models/car.py."},"1":{"message":"The class shell should be constructible with no arguments yet."}},"sourceChecks":{"0":{"message":"Define `Car` in `models/car.py` with `pass` in its body."}}},"try_class_files_and_instances_sketch1":{"title":"Import and use Car from the model file","prompt":"`models/car.py` already defines the empty `Car` class. In `main.py`, import `Car` from the `models.car` module and create one `Car` object. Keep the class definition in `models/car.py`; do not copy the class into `main.py`. No output is required.","hint":"Import the class from the model module, then call the imported class to create one object.","help":{"concept":"A model file owns the class definition. Another file imports that class and can then create objects from it.","hint_1":"The module path is `models.car`.","hint_2":"After importing `Car`, call `Car()` once in `main.py`."},"starterCode":"# Import the Car class.\n# Then create one Car object.","starterFiles":{"main_py":{"content":"# Import the Car class.\n# Then create one Car object."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Import Car and create one object.\nclass Car:\n pass"}},"solutionCode":"from models.car import Car\n\ncar = Car()","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car()"},"models_car_py":{"content":"class Car:\n pass"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should still be constructible with no arguments."},"2":{"message":"Create one Car object in main.py."}},"sourceChecks":{"0":{"message":"Import the `Car` class/module from `models.car` in `main.py`."}}},"try_class_files_and_instances_sketch2":{"title":"Keep the model and main script separate","prompt":"Keep the `Car` class in `models/car.py`. Keep `main.py` as the small script that imports the class and creates one object. Add `print(\"Car object ready\")` in `main.py` so the program shows that it ran.","hint":"Do not move the class into `main.py`. Import it from the model file.","help":{"concept":"A clean multifile project keeps model code in a model file and keeps the main script focused on using that model.","hint_1":"`models/car.py` should contain the class.","hint_2":"`main.py` should import `Car`, create `car = Car()`, and print the ready message."},"starterCode":"from models.car import Car\n\ncar = Car()\n\n# Print a short ready message below.","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car()\n\n# Print a short ready message below."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Keep the model and main script separate.\nclass Car:\n pass"}},"solutionCode":"from models.car import Car\n\ncar = Car()\nprint(\"Car object ready\")","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car()\nprint(\"Car object ready\")"},"models_car_py":{"content":"class Car:\n pass"}},"checks":{"0":{"message":"Keep the Car class defined in the model file."},"1":{"message":"Car should still be constructible with no arguments."},"2":{"message":"Create one Car object in main.py."},"3":{"message":"Print one short ready message from main.py."}},"expectedOutput":"Car object ready"}},"practice":{"mc-class-files-and-instances-class-role":{"title":"Separate the two files","prompt":"Which statements keep the class definition and the script that uses it cleanly separated? Choose all that apply.","hint":"The model file owns the class definition; `main.py` imports and uses it.","help":{"concept":"A clean file boundary keeps reusable model code in the model file and keeps `main.py` focused on using that model.","hint_1":"Look for one statement about `models/car.py` and one about `main.py`.","hint_2":"Do not duplicate the class definition in `main.py`."},"options":{"a":"`models/car.py` defines the `Car` class.","b":"`main.py` imports `Car` and creates objects from it.","c":"`main.py` should copy the full `Car` class definition before using it.","d":"`models/car.py` should run the whole program and print the final output."}},"sc-class-files-and-instances-pass-meaning":{"title":"Why use pass?","prompt":"Why can an empty class use `pass`?","hint":"`pass` lets Python keep a block valid even when there is no real code yet.","help":{"concept":"`pass` is a placeholder. It keeps an empty class body syntactically valid until you add real code later.","hint_1":"A class body cannot be completely empty.","hint_2":"Choose the answer about a placeholder."},"options":{"a":"`pass` creates every method automatically.","b":"`pass` is a placeholder that keeps the empty class valid.","c":"`pass` imports the class into main.py.","d":"`pass` prints the object."}},"fb-class-files-and-instances-import-name":{"title":"Complete the module path","prompt":"Complete the import so `main.py` imports `Car` from the file `models/car.py`.","hint":"Python module paths use dots instead of `/` and omit the `.py` extension.","help":{"concept":"The file path `models/car.py` is imported with the module path `models.car`.","hint_1":"Replace the slash with a dot.","hint_2":"Use `models.car`."},"template":"from [blank1] import Car","choices":["models.car","models/car.py","car","main"]},"dr-class-files-and-instances-order":{"title":"Order the first class workflow","prompt":"Put the steps in the order you follow when creating a class in a model file.","hint":"Start with the class file before importing it.","help":{"concept":"A clean first workflow is: define the class, import it, create one object, then run main.py.","hint_1":"You cannot import a class that has not been defined yet.","hint_2":"Creating the object comes after the import."},"tokens":{"t1":"Define the class in models/car.py","t2":"Import Car in main.py","t3":"Create one object with Car()","t4":"Run main.py"}},"project-step-account-class":{"title":"Create the Account class","prompt":"Practice creating a small account model. Define an `Account` class in `models/account.py` with an `__init__(self, owner, balance)` constructor that stores `owner` and `balance`. In the main code, create `Account(\"Ava\", 120)` and print the owner on one line and the balance on the next line.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"# main.py\nfrom models.account import Account\n\n# Create Ava's account and print owner then balance.","starterFiles":{"main_py":{"content":"from models.account import Account\n\n# Create Ava's account and print owner then balance."},"models_account_py":{"content":""}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\nprint(account.owner)\nprint(account.balance)"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\nprint(account.owner)\nprint(account.balance)","checks":{"0":{"message":"Define a class named Account."},"1":{"message":"Account should accept owner and balance."},"2":{"message":"Store owner and balance on the Account instance."},"3":{"message":"Create one Account object in the main code."},"4":{"message":"Print the owner and balance on separate lines."}}},"project-step-account-methods":{"title":"Add account methods","prompt":"Practice putting account behavior on the model. Keep the provided `Account` class with `owner` and `balance`, then add a `deposit(self, amount)` method that increases the balance and a `summary(self)` method that returns `<owner>: $<balance>`. The main code creates `Account(\"Ava\", 120)`, deposits `30`, and prints the summary.","hint":"One method changes state, and the other reports the current state.","help":{"concept":"This step checks that methods can both update object state and return text based on the updated attributes.","hint_1":"`deposit` should add the incoming amount to `self.balance`.","hint_2":"After calling `deposit(30)`, the summary should reflect the new balance, not the original one."},"starterCode":"# main.py\nfrom models.account import Account\n\naccount = Account(\"Ava\", 120)\n\n# Deposit 30, then print the summary.","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\n\n# Deposit 30, then print the summary."},"models_account_py":{"content":""}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\naccount.deposit(30)\nprint(account.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def summary(self):\n return f\"{self.owner}: ${self.balance}\"\n\n def deposit(self, amount):\n self.balance += amount\n return self.balance"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\naccount.deposit(30)\nprint(account.summary())","checks":{"0":{"message":"Keep the Account class defined."},"1":{"message":"Account should still store owner and balance."},"2":{"message":"summary() should report the current owner and balance."},"3":{"message":"summary() should exist before any deposit."},"4":{"message":"deposit(30) should update the balance to 150."},"5":{"message":"Create one Account object in the main code."},"6":{"message":"Print the summary after depositing."}}},"project-step-two-accounts":{"title":"Keep state separate across two accounts","prompt":"Practice working with two instances of the same class. Keep the provided `Account` class with `owner`, `balance`, `deposit`, and `summary`. The main code creates Ava and Noah accounts and deposits into Ava's account only. Finish the code so the two printed summaries show that each object keeps its own state.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"# main.py\nfrom models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\n# Deposit 30 into Ava's account only.\n# Print Ava's summary, then Noah's summary.","starterFiles":{"main_py":{"content":"from models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\n# Deposit 30 into Ava's account only.\n# Print Ava's summary, then Noah's summary."},"models_account_py":{"content":""}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\nava_account.deposit(30)\nprint(ava_account.summary())\nprint(noah_account.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n self.balance += amount\n\n def summary(self):\n return f\"{self.owner}: ${self.balance}\""}},"solutionCode":"from models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\nava_account.deposit(30)\nprint(ava_account.summary())\nprint(noah_account.summary())","checks":{"0":{"message":"Keep the Account class defined."},"1":{"message":"Each Account should store owner and balance."},"2":{"message":"Ava's account should update to 150 after deposit(30)."},"3":{"message":"Noah's summary should still show the original balance."},"4":{"message":"Create two Account objects in the main code."},"5":{"message":"Print both account summaries on separate lines."}}}}},"constructors-and-object-state":{"label":"Constructors and Object State","summary":"Use `__init__` to create per-object state, distinguish instance state from class-level state, and keep mutable lists separate between objects.","cards":{"sketch0":{"title":"Initialize object state"},"sketch1":{"title":"Class state vs instance state"},"sketch2":{"title":"Keep mutable state per object"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_constructors_and_object_state_sketch0":{"title":"Initialize a Car's state","prompt":"`main.py` already creates a `Car` and reads its attributes. In `models/car.py`, replace the empty class body with `__init__(self, make, model, miles)`. Store the incoming values on `self.make`, `self.model`, and `self.miles`. Leave `main.py` unchanged.","hint":"The constructor receives the three starting values and assigns each one to an attribute on `self`.","help":{"concept":"`__init__` establishes instance state when an object is created.","hint_1":"Define `__init__` inside `class Car`.","hint_2":"Assign make, model, and miles to matching attributes on `self`."},"starterCode":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n # Add __init__ so each Car stores make, model, and miles.\n pass\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should be constructible with make, model, and miles."},"2":{"message":"Store make, model, and miles as attributes on the object."},"3":{"message":"Print the requested attributes on separate lines."}},"expectedOutput":"Nissan\n6000","sourceChecks":{"0":{"message":"Define `__init__(self, make, model, miles)` inside `Car`."},"1":{"message":"Store `make` on `self.make`."},"2":{"message":"Store `model` on `self.model`."},"3":{"message":"Store `miles` on `self.miles`."}}},"try_constructors_and_object_state_sketch1":{"title":"Add one class-level value","prompt":"In `models/car.py`, add the class variable `wheels = 4` directly inside `class Car`, outside `__init__`. Keep `make`, `model`, and `miles` as instance variables on `self`. In `main.py`, print `Car.wheels`, then `outback.make`, then `mini.make`, each on its own line.","hint":"The shared value belongs in the class body; values that differ between cars stay on `self`.","help":{"concept":"A class variable is class-level state; instance variables live on one object through `self`.","hint_1":"Put `wheels = 4` above `__init__`, not inside it.","hint_2":"Read the shared value with `Car.wheels`."},"starterCode":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\n# Print the class-level wheel count, then each car's make.\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\n# Print the class-level wheel count, then each car's make.\n"},"models_car_py":{"content":"class Car:\n # Add the class variable wheels = 4 here.\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n"}},"solutionCode":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\nprint(Car.wheels)\nprint(outback.make)\nprint(mini.make)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\nprint(Car.wheels)\nprint(outback.make)\nprint(mini.make)\n"},"models_car_py":{"content":"class Car:\n wheels = 4\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should still accept make, model, and miles."},"2":{"message":"Keep make, model, and miles as per-object attributes."},"3":{"message":"Create two Car objects in main.py."},"4":{"message":"Print the shared wheel count and the two requested makes."}},"expectedOutput":"4\nSubaru\nMini","sourceChecks":{"0":{"message":"Define `wheels = 4` as a class variable directly inside `Car`."},"1":{"message":"Print the shared value from `Car.wheels`."},"2":{"message":"Print `outback.make`."},"3":{"message":"Print `mini.make`."}}},"try_constructors_and_object_state_sketch2":{"title":"Give each Car its own mutable list","prompt":"`main.py` already creates two cars, appends one service note to the first car, and prints both lists. In `models/car.py`, create `self.service_notes = []` inside `__init__` so every `Car` gets a separate list. Leave `main.py` unchanged.","hint":"Create the empty list on `self` inside the constructor, not once in the class body.","help":{"concept":"Mutable per-object state should be created separately for each instance.","hint_1":"Add the list assignment inside `__init__`.","hint_2":"The required attribute is `self.service_notes`."},"starterCode":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n"},"models_car_py":{"content":"class Car:\n wheels = 4\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n # Give each Car its own empty service_notes list.\n"}},"solutionCode":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n"},"models_car_py":{"content":"class Car:\n wheels = 4\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n self.service_notes = []\n"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should still accept make, model, and miles."},"2":{"message":"Each Car should receive its own service_notes list."},"3":{"message":"Create two Car objects."},"4":{"message":"Only the first car should contain the new service note."}},"expectedOutput":"['oil change']\n[]","sourceChecks":{"0":{"message":"Create `self.service_notes = []` inside `__init__`."}}}},"practice":{"mc-constructors-and-object-state-storing-values":{"title":"Class state or instance state?","prompt":"Which statements correctly distinguish class variables from instance variables? Choose all that apply.","hint":"Values on `self` belong to one object; values such as `Car.wheels` live at the class level.","help":{"concept":"Instance variables are stored on one object through `self`. Class variables are defined in the class body.","hint_1":"Look for `self.` when identifying per-object state.","hint_2":"A class-level value can be read from the class itself."},"options":{"a":"`self.make` can differ from one `Car` object to another.","b":"`Car.wheels` is class-level state.","c":"Every value assigned on `self` is shared by all `Car` objects.","d":"A class variable is recreated separately inside every object."}},"sc-constructors-and-object-state-purpose":{"title":"Where should per-car notes live?","prompt":"Each `Car` needs a separate mutable list of service notes. Where should that list be created?","hint":"The list must be new for each object.","help":{"concept":"Create mutable per-object data inside `__init__` and assign it to `self`.","hint_1":"Avoid one list shared in the class body.","hint_2":"Choose the option that creates a fresh list per `Car`."},"options":{"a":"Inside `__init__` as `self.service_notes = []`","b":"Once in the class body as `service_notes = []`","c":"Only as a local list in `main.py`","d":"Inside a `print()` call"}},"fb-constructors-and-object-state-init-name":{"title":"Name the initializer","prompt":"Complete the method definition Python uses to initialize each new `Car` with starting state.","hint":"The special method name starts and ends with two underscores.","help":{"concept":"`__init__` runs when a new object is created and establishes its starting instance state.","hint_1":"The name means initialize.","hint_2":"Use `__init__`."},"template":"def [blank1](self, make, model, miles):","choices":["__init__","init","constructor","self"]},"dr-constructors-and-object-state-flow":{"title":"Order the state setup","prompt":"Put these steps in a clear order.","hint":"Define shared information first, then create per-object state.","help":{"concept":"The class body can hold shared values; the constructor creates each object's own state.","hint_1":"The class definition comes first.","hint_2":"Use the object after it has been created."},"tokens":{"t1":"Define the class variable in the class body","t2":"Define `__init__` with starting values","t3":"Store per-object values on `self`","t4":"Create an object and read its state"}},"ci-constructors-and-object-state-add-method":{"title":"Add a summary method that reads object state","prompt":"The tracker wants a readable summary for each transaction. In `models/transaction.py`, keep the constructor and add a `summary` method that returns text in this format: `Coffee: -4` or `Paycheck: 1200`. The method should build the string from the object's stored attributes.","hint":"Read the task \"Add a summary method that reads object state\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Add a summary method that reads object state\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n","solutionCode":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n","starterFiles":{"main_py":{"content":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n"},"models_transaction_py":{"content":"class Transaction:\n def __init__(self, label, amount):\n self.label = label\n self.amount = amount\n\n # Add summary() so it returns text built from the stored attributes.\n"}},"solutionFiles":{"main_py":{"content":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n"},"models_transaction_py":{"content":"class Transaction:\n def __init__(self, label, amount):\n self.label = label\n self.amount = amount\n\n def summary(self):\n return f\"{self.label}: {self.amount}\"\n"}},"checks":{"0":{"message":"Define a Transaction class."},"1":{"message":"Transaction should still accept label and amount."},"2":{"message":"summary should return text built from the stored label and amount."},"3":{"message":"summary should work for different transaction objects too."}}},"ci-constructors-and-object-state-deposit-method":{"title":"Track deposits on an account object","prompt":"Return to `models/account.py`. Define an `Account` class with a constructor that stores `owner` and `balance`, then add a `deposit` method that increases the balance. The provided workspace will create an account, make one or more deposits, and inspect the final stored balance.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n","solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n pass\n\n def deposit(self, amount):\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n self.balance = self.balance + amount\n"}},"checks":{"0":{"message":"Define an Account class."},"1":{"message":"Account should accept owner and balance."},"2":{"message":"A deposit should increase the stored balance."},"3":{"message":"Multiple deposits should keep updating the same balance attribute."}}},"ci-constructors-and-object-state-ledger-step":{"title":"Build a ledger account that keeps owner, balance, and note","prompt":"The tracker now wants a slightly richer account model. In `models/account.py`, define an `Account` class whose constructor accepts `owner`, `balance`, and `note`. Store all three as attributes. Then add a `deposit` method that increases `balance` and a `describe` method that returns text in this format: `Rae | 90 | starter fund`. The workspace will create an object, update it, and call `describe()`.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n","solutionCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance, note):\n pass\n\n def deposit(self, amount):\n pass\n\n def describe(self):\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance, note):\n self.owner = owner\n self.balance = balance\n self.note = note\n\n def deposit(self, amount):\n self.balance = self.balance + amount\n\n def describe(self):\n return f\"{self.owner} | {self.balance} | {self.note}\"\n"}},"checks":{"0":{"message":"Define an Account class."},"1":{"message":"Account should accept owner, balance, and note."},"2":{"message":"Store all three constructor values as instance attributes."},"3":{"message":"deposit should update the stored balance."},"4":{"message":"describe should return a string built from the stored state."}}}}},"encapsulation-and-validation":{"label":"Encapsulation and Validation","summary":"Protect object state by validating state-changing methods, then use a property setter when direct attribute assignment also needs one controlled validation path.","cards":{"sketch0":{"title":"Validate state-changing methods"},"sketch1":{"title":"Protect direct assignment with a property"},"sketch2":{"title":"Clean final behavior"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_encapsulation_and_validation_sketch0":{"title":"Protect mileage inside drive()","prompt":"`main.py` is already complete. In `models/car.py`, update the existing `drive(self, miles)` method so it changes `self.miles` only when the requested `miles` value is greater than `0`. For zero or a negative value, leave the stored mileage unchanged. Always return the car's current mileage. Leave `main.py` unchanged.","hint":"Check the requested distance before mutating `self.miles`, then return the current mileage.","help":{"concept":"Validation belongs next to the state change it protects. Invalid requests should not mutate the object.","hint_1":"Only positive distances are valid.","hint_2":"Return the current mileage after the validation decision."},"starterCode":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n # Validate the requested distance before changing self.miles.\n self.miles += miles\n return self.miles\n"}},"solutionCode":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n if miles > 0:\n self.miles += miles\n return self.miles\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should still accept make, model, and starting mileage."},"2":{"message":"A positive drive should update and return the new mileage."},"3":{"message":"A negative drive must leave the mileage unchanged."},"4":{"message":"Zero and negative requests must preserve state for other valid starting values too."}},"expectedOutput":"110\n110","sourceChecks":{"0":{"message":"Keep the validation inside `drive(self, miles)` on `Car`."}}},"try_encapsulation_and_validation_sketch1":{"title":"Validate direct mileage assignment","prompt":"`main.py` is already complete. In `models/car.py`, keep `_miles` as the backing attribute and add a `miles` property. The `@property` getter `miles(self)` must return the backing mileage. Add a `@miles.setter` setter that changes the backing mileage only when the new value is `0` or greater. Negative assignments must leave the current mileage unchanged. Keep `__init__` routing the starting value through `self.miles = miles`. Leave `main.py` unchanged.","hint":"The getter exposes the backing value. The setter validates before replacing that value.","help":{"concept":"A property preserves normal attribute syntax while giving the object one controlled validation path.","hint_1":"Use `@property` for the getter and `@miles.setter` for the setter.","hint_2":"Only non-negative values should replace `_miles`."},"starterCode":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self._miles = 0\n self.miles = miles\n\n # Add the miles property getter and setter below.\n"}},"solutionCode":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self._miles = 0\n self.miles = miles\n\n @property\n def miles(self):\n return self._miles\n\n @miles.setter\n def miles(self, value):\n if value >= 0:\n self._miles = value\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should remain constructible with a valid starting mileage."},"2":{"message":"The public `miles` attribute should still be readable."},"3":{"message":"Print the final miles."}},"expectedOutput":"100\n150\n150","sourceChecks":{"0":{"message":"Define `miles` with the `@property` decorator."},"1":{"message":"Define a setter for the `miles` property."},"2":{"message":"Route the constructor's starting mileage through the `miles` property."}}},"try_encapsulation_and_validation_sketch2":{"title":"Use validated behavior with a summary","prompt":"Use the final validated `Car` class. In `main.py`, create `Car(\"Honda\", \"Civic\", 0)`, call `drive(20)`, call `drive(-3)`, call `drive(50)`, then print `summary()`. The invalid call should be ignored, so the summary should show `70` miles.","hint":"The negative drive should not change the object. The two positive drives should add up to 70 miles.","help":{"concept":"Encapsulation means the object protects its own state and reports a trustworthy result.","hint_1":"Call the methods in the order given.","hint_2":"Print `car.summary()` after all three calls."},"starterCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\n\n# Drive 20 miles, ignore -3, then drive 50 more.\n# Print the final summary.","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\n\n# Drive 20 miles, ignore -3, then drive 50 more.\n# Print the final summary."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Use validated behavior with a summary.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n if miles > 0:\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\ncar.drive(20)\ncar.drive(-3)\ncar.drive(50)\n\nprint(car.summary())","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\ncar.drive(20)\ncar.drive(-3)\ncar.drive(50)\n\nprint(car.summary())"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n if miles > 0:\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"The final summary should use validated miles."},"1":{"message":"Print one clean summary line."},"2":{"message":"Print one clean summary line."}},"expectedOutput":"Honda Civic - 70 miles"}},"practice":{"mc-encapsulation-and-validation-safe-design":{"title":"Choose controlled state changes","prompt":"Which designs keep validation close to the state it protects? Choose all that apply.","hint":"Look for one controlled path that every caller uses.","help":{"concept":"State-changing methods and property setters can both keep a validation rule inside the object.","hint_1":"A method can validate before mutation.","hint_2":"A property setter can validate direct assignment."},"options":{"a":"`drive()` checks a distance before changing the car's mileage.","b":"`main.py` directly repairs `_miles` whenever a value looks wrong.","c":"A `miles` property setter validates `car.miles = value` assignments.","d":"Every caller invents its own validation rule before touching the object."}},"sc-encapsulation-and-validation-why-inside-class":{"title":"Why use a property setter?","prompt":"Why is a property setter useful for a value such as `miles`?","hint":"Think about normal assignment syntax plus validation.","help":{"concept":"A property setter lets callers assign normally while the object controls whether the new value is accepted.","hint_1":"The caller can still write `car.miles = value`.","hint_2":"The setter owns the validation rule."},"options":{"a":"It prevents callers from reading the attribute at all.","b":"It keeps normal assignment syntax while validating the new value inside the object.","c":"It makes every instance share one mileage value.","d":"It removes the need for an initializer."}},"fb-encapsulation-and-validation-condition":{"title":"Trace a rejected assignment","prompt":"A car currently has `miles = 150`. Its property setter ignores negative values. After `car.miles = -20`, what is `car.miles`?","hint":"A rejected assignment leaves the stored state unchanged.","help":{"concept":"Validation protects the existing object state when an assignment is invalid.","hint_1":"The setter does not accept `-20`.","hint_2":"The previous value remains `150`."},"template":"car.miles == [blank1]","choices":["150","-20","0","170"]},"dr-encapsulation-and-validation-update-order":{"title":"Order the safe update","prompt":"Put the validation workflow in order.","hint":"Check the value before changing the attribute.","help":{"concept":"Safe methods receive a value, check it, update only if allowed, then return the current state.","hint_1":"Never update before checking.","hint_2":"Returning happens after the check/update decision."},"tokens":{"t1":"Receive the requested value","t2":"Check whether the value is valid","t3":"Update state only when valid","t4":"Return the current state"}},"ci-account-summary-method":{"title":"Create a summary method for account state","prompt":"A volunteer dashboard needs a readable account summary. In `models/account.py`, complete `summary` so it returns a string in this exact format: `Owner: <owner>, Balance: <balance>`. Do not print inside the method; return the string instead. `main.py` already prints the returned summary for two accounts.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())","starterFiles":{"main_py":{"content":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def summary(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def summary(self):\n return f\"Owner: {self.owner}, Balance: {self.balance}\""}},"solutionCode":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())","checks":{"0":{"message":"Define the Account class."},"1":{"message":"summary should return the formatted string for Mina's account."},"2":{"message":"summary should return the formatted string for Leo's account."}}},"ci-account-withdraw":{"title":"Add a validated withdraw method","prompt":"Your club account tracker now needs withdrawals. In `models/account.py`, complete `withdraw` so it subtracts the amount only when the amount is greater than 0 and no larger than the current balance. Return `True` for a successful withdrawal and `False` otherwise. `main.py` already checks one valid and one invalid withdrawal.","hint":"Read the task \"Add a validated withdraw method\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Add a validated withdraw method\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"# main.py\nfrom models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)\n\n# models/account.py\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n # subtract only when the amount is valid\n pass","starterFiles":{"main_py":{"content":"# main.py\nfrom models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)\n\n# models/account.py\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n # subtract only when the amount is valid\n pass"},"models_account_py":{"content":"class Account:\n def __init__(self, balance):\n self.balance = balance\n\n def withdraw(self, amount):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance -= amount\n return True\n return False"}},"solutionCode":"from models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)","checks":{"0":{"message":"Define the Account class."},"1":{"message":"Account should be constructible with owner and balance."},"2":{"message":"A valid withdrawal should return True."},"3":{"message":"A valid withdrawal should reduce the balance."},"4":{"message":"An oversized withdrawal should return False."},"5":{"message":"An invalid withdrawal should leave the balance unchanged."}}},"ci-helper-is_positive_amount":{"title":"Build a helper that checks positive amounts","prompt":"Your team wants a reusable validation helper. In `helpers/validation.py`, complete `is_positive_amount` so it returns `True` when the number is greater than 0 and `False` otherwise. `main.py` uses that helper inside `Account.deposit`, so the helper must work for both valid and invalid amounts.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"# main.py\nfrom helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)\n\n# helpers/validation.py\ndef is_positive_amount(amount):\n # return True only for amounts greater than 0\n pass\n\n# models/account.py\nfrom helpers.validation import is_positive_amount\n\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if is_positive_amount(amount):\n self.balance += amount\n return True\n return False","starterFiles":{"main_py":{"content":"# main.py\nfrom helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)\n\n# helpers/validation.py\ndef is_positive_amount(amount):\n # return True only for amounts greater than 0\n pass\n\n# models/account.py\nfrom helpers.validation import is_positive_amount\n\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if is_positive_amount(amount):\n self.balance += amount\n return True\n return False"},"models_account_py":{"content":"class Account:\n def __init__(self, balance):\n self.balance = balance\n\n def deposit(self, amount):\n pass"},"helpers_validation_py":{"content":"def is_positive_amount(amount):\n pass"}},"solutionFiles":{"main_py":{"content":"from helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)"},"models_account_py":{"content":"from helpers.validation import is_positive_amount\n\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if is_positive_amount(amount):\n self.balance += amount\n return True\n return False"},"helpers_validation_py":{"content":"def is_positive_amount(amount):\n return amount > 0"}},"solutionCode":"from helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)","checks":{"0":{"message":"10 should be treated as a positive amount."},"1":{"message":"0 should not be treated as a positive amount."},"2":{"message":"Negative numbers should return False."},"3":{"message":"The helper should support a valid deposit."},"4":{"message":"A non-positive amount should leave the balance unchanged."}}}}},"methods-and-responsibility":{"label":"Methods and Responsibility","summary":"Put behavior beside the object state it uses, return useful results from model methods, and keep application-wide coordination outside the model.","cards":{"sketch0":{"title":"Behavior that belongs to one object"},"sketch1":{"title":"Keep responsibilities separated"},"sketch2":{"title":"Static method"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_methods_and_responsibility_sketch0":{"title":"Add behavior that changes one Car","prompt":"`main.py` already creates a `Car`, calls `drive(40)`, and prints both the returned value and the car's final mileage. In `models/car.py`, define the instance method `drive(self, miles)`. It must increase `self.miles` by the given amount, update the object, and return the new mileage. Leave `main.py` unchanged.","hint":"This behavior belongs on `Car` because it changes one car's own mileage.","help":{"concept":"An instance method receives `self` and can change the state stored on that object.","hint_1":"Define `drive(self, miles)` inside `class Car`.","hint_2":"Update `self.miles`, then return its new value."},"starterCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n # Add drive(self, miles) here.\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should still accept make, model, and miles."},"2":{"message":"Keep the existing per-object state."},"3":{"message":"`drive(40)` should return the updated mileage."},"4":{"message":"`drive(40)` must actually update `self.miles`, not only compute a return value."},"5":{"message":"`drive` should work for other valid starting mileages and distances."},"6":{"message":"Keep the provided two-line demonstration in `main.py`."}},"expectedOutput":"10040\n10040","sourceChecks":{"0":{"message":"Define `drive(self, miles)` as an instance method on `Car`."}}},"try_methods_and_responsibility_sketch1":{"title":"Return a summary of one Car","prompt":"`main.py` already creates one `Car` and prints `car.summary()`. In `models/car.py`, define the instance method `summary(self)`. Return a string in the format `MAKE MODEL - MILES miles` using that object's `make`, `model`, and `miles` attributes. The method must return the string; do not print inside `summary`. Leave `main.py` unchanged.","hint":"The summary belongs on `Car` because it reports one car's state. Return the string so `main.py` can decide to print it.","help":{"concept":"A model method can report one object's state while the caller remains responsible for display or application coordination.","hint_1":"Define `summary(self)` inside `Car`.","hint_2":"Build and return the string from `self.make`, `self.model`, and `self.miles`."},"starterCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n # Add summary(self) here.\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\"\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should remain constructible."},"2":{"message":"`summary()` should return the requested text for the visible car."},"3":{"message":"`summary()` should use the object's actual state, not hard-coded visible values."},"4":{"message":"Keep the provided `main.py` call that prints the returned summary."}},"expectedOutput":"Toyota Prius - 62 miles","sourceChecks":{"0":{"message":"Define `summary(self)` as an instance method on `Car`."}}},"try_methods_and_responsibility_sketch2":{"title":"Add a static validation method","prompt":"Add `@staticmethod` and `is_valid_miles(miles)` to `Car`. It should return `True` when miles is greater than or equal to 0 and `False` otherwise. In `main.py`, call it once from the class with `120` and once from a Car object with `-5`, then print both results.","hint":"A static method uses neither `self` nor `cls`; it receives only the value it checks.","help":{"concept":"A static method is useful for logic related to the class that does not need object state or the class itself.","hint_1":"Place `@staticmethod` above `def is_valid_miles(miles):`.","hint_2":"Return the Boolean expression `miles >= 0`."},"starterCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\n# Print the validation result from the class and from the object.\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\n# Print Car.is_valid_miles(120).\n# Then print car.is_valid_miles(-5).\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n # TODO: add @staticmethod and is_valid_miles(miles).\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\nprint(Car.is_valid_miles(120))\nprint(car.is_valid_miles(-5))\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\nprint(Car.is_valid_miles(120))\nprint(car.is_valid_miles(-5))\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n @staticmethod\n def is_valid_miles(miles):\n return miles >= 0\n"}},"checks":{"0":{"message":"Keep the Car class constructible."},"1":{"message":"is_valid_miles should return True for a non-negative value."},"2":{"message":"is_valid_miles should return False for a negative value."},"3":{"message":"Print both validation results."}},"expectedOutput":"True\nFalse"}},"practice":{"mc-methods-and-responsibility-class-jobs":{"title":"Which behavior belongs on Car?","prompt":"Which behaviors naturally belong as instance methods on one `Car` object? Choose all that apply.","hint":"Choose behavior that reads or changes one car's own state.","help":{"concept":"An instance method is a good fit when the behavior belongs to one object's state.","hint_1":"Think about mileage and one-car summaries.","hint_2":"Fleet-wide reports and user menus coordinate more than one object or the whole application."},"options":{"a":"Increase this car's mileage after it drives.","b":"Return a summary of this car's make, model, and mileage.","c":"Build a report across every car in the fleet.","d":"Ask the user which menu option to choose."}},"sc-methods-and-responsibility-main-role":{"title":"Keep display outside the model","prompt":"Which design keeps `Car.summary()` focused on the model's responsibility?","hint":"The method should provide the result; the caller can decide how to display it.","help":{"concept":"Returning a result keeps a model method reusable while `main.py` owns user-facing coordination.","hint_1":"Avoid putting the application's printing policy inside the model.","hint_2":"Choose the option where `summary()` returns and `main.py` prints."},"options":{"a":"`summary()` prints the text itself and returns nothing.","b":"`summary()` returns the text, and `main.py` prints the returned value.","c":"`main.py` rewrites the Car's attributes before every summary.","d":"`summary()` asks the user which car to summarize."}},"fb-methods-and-responsibility-call-name":{"title":"Trace a state-changing method","prompt":"A car starts with `miles = 10000`. After `car.drive(40)` completes, what should `car.miles` be?","hint":"The method adds the driven distance to the object's current mileage.","help":{"concept":"A state-changing instance method updates the object itself.","hint_1":"Start with 10000.","hint_2":"Add 40."},"template":"car.miles == [blank1]","choices":["10040","10000","40","9960"]},"dr-methods-and-responsibility-flow":{"title":"Choose a method by what it needs","prompt":"Put this decision process in order.","hint":"Start by asking what data the behavior needs.","help":{"concept":"The needed context determines the method type.","hint_1":"Object state points to an instance method.","hint_2":"No object or class context points to a static method."},"tokens":{"t1":"Ask whether the behavior needs one object's state","t2":"Use an instance method when it needs `self`","t3":"Use a class method when it needs `cls` or creates objects","t4":"Use a static method when it needs neither"}},"ci-methods-and-responsibility-report-line":{"title":"Build a report line from object methods","prompt":"You are preparing a simple daily report for the account tracker. Finish the `deposit` and `report_line` methods in `models/account.py`. `deposit` should update the balance, and `report_line` should return text in this exact format: `Rae | balance: $95`. `main.py` already creates the account, deposits money, and prints the report line. When you click Run, the output panel should show `Rae | balance: $95`. This matters because the class should both manage state changes and provide account-specific display text.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n pass\n\n def report_line(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n self.balance += amount\n return self.balance\n\n def report_line(self):\n return f\"{self.owner} | balance: ${self.balance}\""}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())","checks":{"0":{"message":"Define the Account class."},"1":{"message":"deposit should update the balance to 95."},"2":{"message":"report_line should return the formatted report text."}}},"ci-methods-and-responsibility-validate-withdrawal":{"title":"Keep validation inside the method","prompt":"You are improving the account tracker so invalid withdrawals do not change the balance. In `models/account.py`, finish `withdraw` so it subtracts the amount only when the amount is less than or equal to the current balance. If the amount is too large, leave the balance unchanged. The method should return the current balance after the attempt. `main.py` already prints two results. When you click Run, the output panel should show `60` and then `60`. This matters because validation should live with the object state it protects.","hint":"Check the amount against `self.balance` before subtracting.","help":{"concept":"Encapsulation means the class protects its own state. A withdrawal rule belongs inside the method because the method controls balance changes.","hint_1":"The first call should reduce the balance, but the second call should not make it negative.","hint_2":"Use a conditional inside `withdraw`; only update `self.balance` when the requested amount is allowed, then return the balance either way."},"starterCode":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n self.balance -= amount\n return self.balance"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n if amount <= self.balance:\n self.balance -= amount\n return self.balance"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))","checks":{"0":{"message":"Define the Account class."},"1":{"message":"A valid withdrawal should reduce the balance."},"2":{"message":"After an invalid second withdrawal, the balance should remain 60."},"3":{"message":"If the amount is too large, return the unchanged balance."}}},"practice-cart-total-method":{"title":"Put total behavior on the object","prompt":"Define a `Cart` class that stores a list of prices. Add a `total()` method that returns the sum of those prices. Create `Cart([4, 7, 9])` and print `cart.total()`.","hint":"The `Cart` object already owns the price list, so the method should use `self.prices`.","help":{"concept":"A method belongs on an object when the behavior primarily uses and represents that object's own state.","hint_1":"The `Cart` object already owns the price list, so the method should use `self.prices`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n # return the total of this cart\n pass\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n","starterFiles":{"main_py":{"content":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n # return the total of this cart\n pass\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n"}},"solutionCode":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n return sum(self.prices)\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n","solutionFiles":{"main_py":{"content":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n return sum(self.prices)\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n"}}}}},"module-8-account-tracker-project":{"label":"Module 8 Account Tracker Project","summary":"Build Riverside Club's account tracker so each member balance has one reliable model, safe update rules, and a clear summary.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Account Tracker Build"}},"projectSteps":{"try_module_8_account_tracker_project_sketch0":{"title":"Create the Account model boundary"},"account_tracker_step_2_constructor_attributes":{"title":"Add shared and per-account state"},"account_tracker_step_3_add_methods":{"title":"Add validated account transactions"},"account_tracker_step_4_validation_summary":{"title":"Protect balance and finish the model"}},"moduleProject":{"steps":{"try_module_8_account_tracker_project_sketch0":{"title":"Create the Account model boundary","prompt":"Start the club tracker with the smallest working model boundary. In `models/account.py`, define `class Account:` with `pass` as its body. In `main.py`, import `Account` from `models.account` and create one `Account` object. Do not add state or output yet.","hint":"Keep the reusable class definition in `models/account.py`; `main.py` only imports and uses it.","help":{"concept":"A model file owns the reusable class; main.py imports and uses it.","hint_1":"Define the empty class shell in models/account.py.","hint_2":"Import Account in main.py and call Account() once."},"starterCode":"from models.account import Account\n\n# Create one Account object below.\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\n# Create one Account object below.\n"},"models_account_py":{"content":"# Define the Account class shell below.\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account()\n"},"models_account_py":{"content":"class Account:\n pass\n"}},"solutionCode":"from models.account import Account\n\naccount = Account()\n","checks":{"0":{"message":"Keep `Account` defined in `models/account.py`."},"1":{"message":"The empty `Account` class should be constructible."},"2":{"message":"Create at least one `Account` object in `main.py`."}},"sourceChecks":{"0":{"message":"Define the empty `Account` class shell with `pass` in `models/account.py`."},"1":{"message":"Import the Account model from `models.account` in `main.py`."}}},"account_tracker_step_2_constructor_attributes":{"title":"Add shared and per-account state","prompt":"Continue from the exact previous workspace. In `models/account.py`, replace the empty class body with the class variable `club_name = \"Riverside Club\"` and `__init__(self, owner, balance)`. Store the incoming values on `self.owner` and `self.balance`. In `main.py`, read an owner and integer balance from input, create the account, then print `Account.club_name`, `account.owner`, and `account.balance`, each on its own line.","hint":"The club name is shared class state. Owner and balance belong to each individual account.","help":{"concept":"Class variables hold shared class-level state; self stores per-object state.","hint_1":"Put club_name directly in the class body.","hint_2":"Store owner and balance on self inside __init__."},"starterCode":"from models.account import Account\n\naccount = Account()\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account()\n"},"models_account_py":{"content":"class Account:\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n"}},"solutionCode":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n","checks":{"0":{"message":"Keep `Account` defined in the model file."},"1":{"message":"Account should be constructible with different owners and balances."},"2":{"message":"Each Account should expose owner and balance state."},"3":{"message":"Create an Account from the input values in `main.py`."},"4":{"message":"Print the shared club name, owner, and balance."}},"expectedOutput":"Riverside Club\nAva\n125","sourceChecks":{"0":{"message":"Define `club_name = \"Riverside Club\"` as class-level state on Account."},"1":{"message":"Define `__init__(self, owner, balance)` on Account."},"2":{"message":"Store the incoming owner on `self.owner`."},"3":{"message":"Store the incoming balance on `self.balance`."}}},"account_tracker_step_3_add_methods":{"title":"Add validated account transactions","prompt":"Continue from the exact previous workspace. In `models/account.py`, add the instance methods `deposit(self, amount)` and `withdraw(self, amount)`. A deposit changes the balance only when `amount > 0`. A withdrawal changes the balance only when `amount > 0` and the amount does not exceed the current balance. Both methods must always return the current balance. In `main.py`, demonstrate a valid deposit, a valid withdrawal, a negative deposit, and an overdraw attempt using the provided values in the solution behavior.","hint":"Keep each validation rule inside the method that owns that state change. Rejected transactions leave the balance unchanged.","help":{"concept":"Instance methods own validated changes to one Account's balance.","hint_1":"deposit accepts only positive amounts.","hint_2":"withdraw also checks that the account has enough balance."},"starterCode":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if amount > 0:\n self.balance += amount\n return self.balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance -= amount\n return self.balance\n"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n","checks":{"0":{"message":"A valid deposit should update and return the new balance."},"1":{"message":"A negative deposit must leave the balance unchanged."},"2":{"message":"A valid withdrawal should update and return the remaining balance."},"3":{"message":"An overdraw attempt must leave the balance unchanged."},"4":{"message":"The methods should preserve correct state on other valid and invalid values too."}},"expectedOutput":"150\n110\n110\n110","sourceChecks":{"0":{"message":"Define `deposit(self, amount)` as an instance method."},"1":{"message":"Define `withdraw(self, amount)` as an instance method."}}},"account_tracker_step_4_validation_summary":{"title":"Protect balance and finish the model","prompt":"Finish the tracker from the exact previous workspace. Refactor `balance` into a validated property backed by `self._balance`. In `__init__`, start the backing value at `0` and route the incoming balance through `self.balance = balance`. Define a `@property` getter `balance(self)` that returns `_balance`, and a `@balance.setter` setter `balance(self, value)` that accepts only values `>= 0`; a negative assignment must leave the current balance unchanged. Keep `deposit()` and `withdraw()` working through the public `balance` property. Add `summary(self)` that returns `CLUB | OWNER: $BALANCE` with two decimal places. Update `main.py` to read the owner, starting balance, a new direct balance, and an invalid direct balance from input; print the starting balance, the accepted balance, the balance after the rejected assignment, then the summary.","hint":"The property gives construction, direct assignment, and the transaction methods one public balance interface while `_balance` remains internal.","help":{"concept":"A property controls direct assignment while preserving normal attribute syntax.","hint_1":"Initialize `_balance` before routing the constructor value through the setter.","hint_2":"summary() returns text; main.py decides to print it."},"starterCode":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if amount > 0:\n self.balance += amount\n return self.balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance -= amount\n return self.balance\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nowner = input()\nstart_balance = int(input())\nnew_balance = int(input())\ninvalid_balance = int(input())\n\naccount = Account(owner, start_balance)\n\nprint(account.balance)\n\naccount.balance = new_balance\nprint(account.balance)\n\naccount.balance = invalid_balance\nprint(account.balance)\n\nprint(account.summary())\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self._balance = 0\n self.balance = balance\n\n @property\n def balance(self):\n return self._balance\n\n @balance.setter\n def balance(self, value):\n if value >= 0:\n self._balance = value\n\n def deposit(self, amount):\n if amount > 0:\n self.balance = self.balance + amount\n return self.balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance = self.balance - amount\n return self.balance\n\n def summary(self):\n return f\"{self.club_name} | {self.owner}: ${self.balance:.2f}\"\n"}},"solutionCode":"from models.account import Account\n\nowner = input()\nstart_balance = int(input())\nnew_balance = int(input())\ninvalid_balance = int(input())\n\naccount = Account(owner, start_balance)\n\nprint(account.balance)\n\naccount.balance = new_balance\nprint(account.balance)\n\naccount.balance = invalid_balance\nprint(account.balance)\n\nprint(account.summary())\n","checks":{"0":{"message":"Account should remain constructible after the property refactor."},"1":{"message":"The public owner and balance state should remain readable."},"2":{"message":"deposit() should still work after the property refactor."},"3":{"message":"withdraw() should still work through the public balance property."},"4":{"message":"summary() should use the actual account state, not the visible example values."}},"expectedOutput":"125\n40\n40\nRiverside Club | Ava: $40.00","sourceChecks":{"0":{"message":"Define `balance` with the `@property` decorator."},"1":{"message":"Define `balance(self, value)` as the property setter."},"2":{"message":"Initialize the internal `_balance` backing value before using the setter."},"3":{"message":"Route the constructor's incoming balance through the public property."},"4":{"message":"Define `summary(self)` on Account."}}}}}},"thinking-in-objects":{"label":"Thinking in Objects","summary":"Use provided objects first so object creation, attributes, and method calls make sense before writing class syntax yourself.","cards":{"course-introduction":{"title":"Course introduction"},"sketch0":{"title":"Create objects"},"sketch1":{"title":"Read attributes"},"sketch2":{"title":"Call methods"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_thinking_in_objects_sketch0":{"title":"Create two objects","prompt":"A `Car` model is already provided in `models/car.py`. In `main.py`, create two separate `Car` objects with sensible make, model, and mileage values. Keep both objects available in variables or a collection. Do not print anything. This exercise is only about creating objects.","hint":"Call `Car(...)` twice. Each constructor call creates a separate object.","help":{"concept":"Calling a class creates an object. Separate constructor calls create separate instances, each with its own state.","hint_1":"The provided constructor accepts a make, a model, and a starting mileage.","hint_2":"Create two `Car(...)` instances and keep both reachable. No output is required."},"starterCode":"from models.car import Car\n\n# A Car model is already provided.\n# Create two Car objects below.\n# Do not print anything yet.","starterFiles":{"main_py":{"content":"from models.car import Car\n\n# A Car model is already provided.\n# Create two Car objects below.\n# Do not print anything yet."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Create two car objects.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncivic_car = Car(\"Honda\", \"Civic\", 12000)\nfocus_car = Car(\"Ford\", \"Focus\", 8000)","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncivic_car = Car(\"Honda\", \"Civic\", 12000)\nfocus_car = Car(\"Ford\", \"Focus\", 8000)"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"Use the provided Car class."},"1":{"message":"Create Car objects with make, model, and miles."},"2":{"message":"Each Car object should keep its own make, model, and miles values."},"3":{"message":"Create at least two Car objects."}},"sourceChecks":{}},"try_thinking_in_objects_sketch1":{"title":"Read attributes from existing objects","prompt":"Two `Car` objects are already created in `main.py`. Use dot notation to print the `make` attribute directly from `corolla_car`, then print the `miles` attribute directly from `mazda_car`, each on its own line. Keep `models/car.py` unchanged.","hint":"Read each requested value from the existing object with dot notation.","help":{"concept":"An attribute is state stored on an object. Dot notation reads that state from a particular instance.","hint_1":"The first value comes from `corolla_car`'s `make` attribute.","hint_2":"The second value comes from `mazda_car`'s `miles` attribute."},"starterCode":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\n# Print the requested attribute from each existing object.\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\n# Print the requested attribute from each existing object.\n"},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Read values from car objects.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\nprint(corolla_car.make)\nprint(mazda_car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\nprint(corolla_car.make)\nprint(mazda_car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"Use the provided Car class."},"1":{"message":"Create Car objects with make, model, and miles."},"2":{"message":"Each Car object should keep its own make, model, and miles values."},"3":{"message":"Create at least two Car objects."},"4":{"message":"Print the requested attributes on separate lines."}},"expectedOutput":"Toyota\n18000","sourceChecks":{"0":{"message":"Print `corolla_car`'s `make` attribute directly with dot notation."},"1":{"message":"Print `mazda_car`'s `miles` attribute directly with dot notation."}}},"try_thinking_in_objects_sketch2":{"title":"Call methods on an existing object","prompt":"A `car` object is already created in `main.py`. Call `car.drive(50)` to change its mileage. Then print `car.summary()` directly so the output comes from the updated object. Keep `models/car.py` unchanged.","hint":"Change the existing object's state first, then ask that same object to summarize its current state.","help":{"concept":"Methods are behavior attached to objects. A method can change an object's state, and another method can report the updated state.","hint_1":"Use the existing variable `car`; do not create a replacement object.","hint_2":"Call the state-changing method before printing the summary."},"starterCode":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\n\n# Drive the car 50 miles.\n# Then print the updated summary.","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\n\n# Drive the car 50 miles.\n# Then print the updated summary."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Call a method on one car object.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\ncar.drive(50)\n\nprint(car.summary())","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\ncar.drive(50)\n\nprint(car.summary())"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"Use the provided Car class."},"1":{"message":"After drive(50), summary() should show the updated miles."},"2":{"message":"Create one Car object."},"3":{"message":"Print the updated car summary."}},"expectedOutput":"Kia Soul - 30050 miles","sourceChecks":{"0":{"message":"Call `drive(50)` on the existing `car` object."},"1":{"message":"Print `car.summary()` directly so the output comes from the updated object."}}}},"practice":{"mc-thinking-in-objects-object-idea":{"title":"Why use objects?","prompt":"Which two statements correctly describe objects in this lesson? Choose all that apply.","hint":"Think about one program thing keeping its related values and actions together.","help":{"concept":"An object represents one thing in a program. It can store values and offer methods that work with those values.","hint_1":"Look for choices about grouping related data and behavior.","hint_2":"Reject choices that say all objects share one state or that objects are only about printing output."},"options":{"a":"Objects help model things the program cares about.","b":"An object can keep related values and useful behavior together.","c":"Every object from one class must share the exact same state forever.","d":"Objects are only useful when the program prints text."}},"sc-thinking-in-objects-attribute-meaning":{"title":"What is an attribute?","prompt":"In this topic, what does an attribute mean?","hint":"Think about values like a car's make, model, or miles.","help":{"concept":"An attribute is a value stored on one specific object.","hint_1":"Dot notation reads an attribute from an object.","hint_2":"Choose the answer about a value stored on one object."},"options":{"a":"A value stored on a specific object.","b":"A file that always runs before main.py.","c":"A kind of loop.","d":"A comment that explains a class."}},"fb-thinking-in-objects-method-call":{"title":"Trace a method change","prompt":"A `Car` object starts with `miles = 30000`. The program calls `car.drive(50)`. What should `car.miles` be afterward?","hint":"The method adds the traveled distance to the object's current mileage.","help":{"concept":"A state-changing method updates data stored on the object.","hint_1":"Start with 30000 and add 50.","hint_2":"The updated mileage is 30050."},"options":{"a":"30000","b":"30050","c":"50","d":"29950"}},"dr-thinking-in-objects-workflow":{"title":"Order the object workflow","prompt":"Put these steps in the usual order for working with an object.","hint":"Start by creating the object before reading or changing it.","help":{"concept":"A clear object workflow is: create an object, read attributes when needed, call methods when behavior is needed, then print or use the result.","hint_1":"An object must exist before you can read from it.","hint_2":"Printing the result comes after the object is created and updated."},"tokens":{"t1":"Create the object with starting values","t2":"Read an attribute from the object","t3":"Call a method on that object","t4":"Print or use the object's current state"}},"practice-book-object-description":{"title":"Create an object with its own data","prompt":"Define a `Book` class whose constructor stores `title` and `pages`. Add a `description()` method that returns `<title> - <pages> pages`. Create `Book(\"Orbit\", 240)` and print its description.","hint":"Store the constructor arguments on `self`, then let the method read those attributes.","help":{"concept":"An object bundles related state with behavior that uses that state.","hint_1":"Store the constructor arguments on `self`, then let the method read those attributes.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Book:\n def __init__(self, title, pages):\n # store both values\n pass\n\n def description(self):\n # return the formatted description\n pass\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n","starterFiles":{"main_py":{"content":"class Book:\n def __init__(self, title, pages):\n # store both values\n pass\n\n def description(self):\n # return the formatted description\n pass\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n"}},"solutionCode":"class Book:\n def __init__(self, title, pages):\n self.title = title\n self.pages = pages\n\n def description(self):\n return f\"{self.title} - {self.pages} pages\"\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n","solutionFiles":{"main_py":{"content":"class Book:\n def __init__(self, title, pages):\n self.title = title\n self.pages = pages\n\n def description(self):\n return f\"{self.title} - {self.pages} pages\"\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n"}}},"practice-two-pet-instances":{"title":"Keep separate state in two objects","prompt":"Define a `Pet` class that stores `name` and `sound`, with a `speak()` method returning `<name>: <sound>`. Create `Pet(\"Milo\", \"meow\")` and `Pet(\"Rex\", \"woof\")`, then print both `speak()` results.","hint":"Each instance should store its own `name` and `sound` attributes.","help":{"concept":"Different instances of the same class keep separate state while sharing the same method definitions.","hint_1":"Each instance should store its own `name` and `sound` attributes.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Pet:\n def __init__(self, name, sound):\n pass\n\n def speak(self):\n pass\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n","starterFiles":{"main_py":{"content":"class Pet:\n def __init__(self, name, sound):\n pass\n\n def speak(self):\n pass\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n"}},"solutionCode":"class Pet:\n def __init__(self, name, sound):\n self.name = name\n self.sound = sound\n\n def speak(self):\n return f\"{self.name}: {self.sound}\"\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n","solutionFiles":{"main_py":{"content":"class Pet:\n def __init__(self, name, sound):\n self.name = name\n self.sound = sound\n\n def speak(self):\n return f\"{self.name}: {self.sound}\"\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n"}}},"practice-task-state-method":{"title":"Let a method change object state","prompt":"Define a `Task` class that stores `title` and starts with `done = False`. Add `complete()` so it sets `done` to `True`. Create one task, call `complete()`, and print its `title` and `done` value on separate lines.","hint":"The method should update `self.done` on the existing object.","help":{"concept":"Methods can change the state stored on an object, allowing the object to manage related data and behavior together.","hint_1":"The method should update `self.done` on the existing object.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Task:\n def __init__(self, title):\n # store title and start done as False\n pass\n\n def complete(self):\n # mark this task complete\n pass\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n","starterFiles":{"main_py":{"content":"class Task:\n def __init__(self, title):\n # store title and start done as False\n pass\n\n def complete(self):\n # mark this task complete\n pass\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n"}},"solutionCode":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n self.done = True\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n","solutionFiles":{"main_py":{"content":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n self.done = True\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n"}}}}}},"python-9-inheritance-polymorphism-and-abstraction":{"abstraction-with-base-interfaces":{"label":"Abstract Base Classes and Interfaces","summary":"Use `ABC` and `@abstractmethod` to make a shared method requirement enforceable, then make a subclass concrete by implementing that method.","cards":{"sketch0":{"title":"Define an enforceable contract"},"sketch1":{"title":"Make a child concrete"},"sketch2":{"title":"Program to shared behavior"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_abstraction_with_base_interfaces_sketch0":{"title":"Make CatalogItem an abstract contract","prompt":"`main.py` is already complete. In `models/catalog_item.py`, import `ABC` and `abstractmethod` from `abc`, make `CatalogItem` inherit from `ABC`, and decorate `label(self)` with `@abstractmethod`. Keep the existing constructor that stores `title`. Leave `main.py` unchanged.","hint":"The class must use `ABC`, and the required `label()` method needs the `@abstractmethod` decorator.","help":{"concept":"An abstract base class can enforce that related concrete subclasses implement a required method.","hint_1":"Import both `ABC` and `abstractmethod` from `abc`.","hint_2":"Place `@abstractmethod` directly above `label(self)`."},"starterCode":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n"},"models_catalog_item_py":{"content":"# Import ABC and abstractmethod from abc.\n\nclass CatalogItem:\n def __init__(self, title):\n self.title = title\n\n # Make label() an abstract method.\n def label(self):\n pass\n"},"models_book_py":{"content":"# Book is used in the next step; leave it unchanged for now.\n"}},"solutionCode":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n","solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"# Book is used in the next step.\n"}},"checks":{"0":{"message":"Define CatalogItem in models/catalog_item.py."},"1":{"message":"CatalogItem should be abstract so Python refuses to instantiate it."}},"expectedOutput":"CatalogItem blocked\nIncompleteItem blocked\nReady","sourceChecks":{"0":{"message":"Import both `ABC` and `abstractmethod` from Python's `abc` module."},"1":{"message":"Make `CatalogItem` inherit from `ABC`."},"2":{"message":"Decorate `label(self)` with `@abstractmethod`."}}},"try_abstraction_with_base_interfaces_sketch1":{"title":"Fulfill the abstract contract in Book","prompt":"`CatalogItem` is already abstract and its constructor already stores `title`. In `models/book.py`, keep `Book` inheriting from `CatalogItem` and implement the required `label(self)` method so it returns `Book: ` followed by that object's title. Do not add another constructor; `Book` should inherit the parent's constructor. Leave `models/catalog_item.py` and `main.py` unchanged.","hint":"Implement the required method directly on `Book`. Once `label()` exists, Python can instantiate the child.","help":{"concept":"A subclass remains abstract until it implements every required abstract method. Shared constructor setup can still be inherited.","hint_1":"Keep `class Book(CatalogItem)`.","hint_2":"Define only `label(self)` and use the inherited `self.title`."},"starterCode":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n # Implement the required label() method.\n pass\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n # TODO: return Movie: <title>.\n pass\n"}},"solutionCode":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n","solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"`Book.label()` should use the object's actual inherited title."},"1":{"message":"`Book.label()` should work for other valid titles too."},"2":{"message":"Print both concrete labels."}},"expectedOutput":"Book: Coraline\nCatalogItem blocked","sourceChecks":{"0":{"message":"Keep `Book` inheriting from the abstract `CatalogItem` contract."},"1":{"message":"Implement the required `label(self)` method on `Book`."}}},"try_abstraction_with_base_interfaces_sketch2":{"title":"Use a helper that trusts the interface","prompt":"Complete `show_labels(items)` in `services/catalog_view.py`. Return one string with each item's `label()` on its own line. The helper does not need `isinstance` checks; it depends only on the shared behavior. `main.py` is already wired to print the returned string.","hint":"Collect each `item.label()` result and join them with `\"\\n\"`.","help":{"concept":"The ABC enforces the contract for this family of classes. The helper itself uses Python's duck-typing style: it only needs each object to provide `label()`.","hint_1":"Use `\"\\n\".join(...)` so there is no extra blank line.","hint_2":"Do not print inside the helper; return one string."},"starterCode":"# Run this provided script after completing show_labels.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n","starterFiles":{"main_py":{"content":"# Run this provided script after completing show_labels.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_view_py":{"content":"def show_labels(items):\n # TODO: return one string with each item.label() on its own line.\n pass\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_view_py":{"content":"def show_labels(items):\n return \"\\n\".join(item.label() for item in items)\n"}},"checks":{"0":{"message":"Return both labels so main.py prints two lines."}},"expectedOutput":"Book: Dune\nMovie: Moana"}},"practice":{"sc-interface-purpose":{"title":"What does the abstract contract enforce?","prompt":"What does `ABC` together with `@abstractmethod` add to `CatalogItem`?","hint":"Think about what Python prevents when required behavior is missing.","help":{"concept":"An abstract base class can prevent incomplete classes from being instantiated.","hint_1":"The contract is about required behavior.","hint_2":"Concrete subclasses can still implement that behavior differently."},"options":{"a":"Python blocks instantiation while a required abstract method is unresolved.","b":"Every subclass must return exactly the same label text.","c":"The abstract parent can no longer store shared state.","d":"Subclasses are no longer allowed to inherit methods."}},"fb-interface-method-name":{"title":"Mark the required method","prompt":"Complete the decorator that marks `label()` as required.","hint":"It comes from Python's `abc` module.","help":{"concept":"`@abstractmethod` marks behavior that concrete subclasses must implement.","hint_1":"The decorator begins with `@`.","hint_2":"Its name combines `abstract` and `method`."},"template":"[blank1]\ndef label(self):\n pass","choices":["@abstractmethod","@staticmethod","@classmethod","@property"]},"dr-interface-build-order":{"title":"Order the ABC workflow","prompt":"Put these steps in a clear order.","hint":"Declare the contract before creating concrete child objects.","help":{"concept":"Import the ABC tools, define the abstract parent, implement the method in children, then use the objects through shared behavior.","hint_1":"Imports come first.","hint_2":"The helper comes after concrete implementations exist."},"tokens":{"t1":"Import `ABC` and `abstractmethod`","t2":"Define the abstract method on the base class","t3":"Implement the method in each concrete child","t4":"Call the shared method from a helper"}},"sc-interface-helper-focus":{"title":"What happens to an incomplete child?","prompt":"`CatalogItem.label()` is abstract. `DraftItem(CatalogItem)` does not implement `label()`. What happens when code tries to create `DraftItem(\"Notes\")`?","hint":"The child still has an unresolved abstract method.","help":{"concept":"A subclass remains abstract until it implements every required abstract method.","hint_1":"Inheritance alone does not make the child concrete.","hint_2":"Python blocks construction of an incomplete child."},"options":{"a":"Python creates the object and uses `pass` as its label.","b":"Python raises `TypeError` because the child is still abstract.","c":"Python automatically copies a `label()` implementation into the child.","d":"Python removes `CatalogItem` from the inheritance chain."}},"ci-catalog-add-audio-subclass":{"title":"Add an audio item that fits the contract","prompt":"The catalog is expanding again. Add an `Audio` subclass that fits the same base-class contract used by the report service.\n\nTasks:\n- In `models/audio.py`, create `Audio(BaseItem)`.\n- Its constructor should accept `title` and `speaker`, call `super().__init__(title)`, and store `speaker`.\n- Override `display_line()` to return `Audio: <title> by <speaker>`.\n- Do not change `services/report_service.py` or `main.py`.\n\nClick Run and confirm the output panel shows lines for a book, a video, and the new audio item.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def display_line(self):\n return self.title\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_line(self):\n return f\"Book: {self.title} by {self.author}\"\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_line(self):\n return f\"Video: {self.title} ({self.minutes} min)\"\n"},"models_audio_py":{"content":"from models.base_item import BaseItem\n\nclass Audio(BaseItem):\n def __init__(self, title, speaker):\n pass\n\n def display_line(self):\n pass\n"},"services_report_service_py":{"content":"def build_report(items):\n lines = []\n for item in items:\n lines.append(item.display_line())\n return lines\n"}},"solutionCode":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def display_line(self):\n return self.title\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_line(self):\n return f\"Book: {self.title} by {self.author}\"\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_line(self):\n return f\"Video: {self.title} ({self.minutes} min)\"\n"},"models_audio_py":{"content":"from models.base_item import BaseItem\n\nclass Audio(BaseItem):\n def __init__(self, title, speaker):\n super().__init__(title)\n self.speaker = speaker\n\n def display_line(self):\n return f\"Audio: {self.title} by {self.speaker}\"\n"},"services_report_service_py":{"content":"def build_report(items):\n lines = []\n for item in items:\n lines.append(item.display_line())\n return lines\n"}},"checks":{"0":{"message":"Define the Audio class."},"1":{"message":"Audio should be constructible with title and speaker."},"2":{"message":"Audio should store title and speaker."},"3":{"message":"Audio.display_line() should match the shared report contract."}}},"ci-catalog-baseitem-checkout":{"title":"Add a checkout message contract","prompt":"Practice a shared checkout-message contract in a small media catalog. In `models/base_item.py`, add `checkout_message()` that returns `<title> is ready`. In `models/book.py`, override it to return `Borrow book: <title>`. In `models/video.py`, override it to return `Play video: <title>`. Keep `services/checkout_service.py` generic so it loops through mixed objects and calls the shared method.","hint":"Read the task \"Add a checkout message contract\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Add a checkout message contract\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def checkout_message(self):\n pass\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def checkout_message(self):\n pass\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def checkout_message(self):\n pass\n"},"services_checkout_service_py":{"content":"def collect_messages(items):\n messages = []\n for item in items:\n messages.append(item.checkout_message())\n return messages\n"}},"solutionCode":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def checkout_message(self):\n return f\"{self.title} is ready\"\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def checkout_message(self):\n return f\"Borrow book: {self.title}\"\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def checkout_message(self):\n return f\"Play video: {self.title}\"\n"},"services_checkout_service_py":{"content":"def collect_messages(items):\n messages = []\n for item in items:\n messages.append(item.checkout_message())\n return messages\n"}},"checks":{"0":{"message":"BaseItem.checkout_message() should return the generic message."},"1":{"message":"Book.checkout_message() should return the book-specific message."},"2":{"message":"Video.checkout_message() should return the video-specific message."}}},"ci-catalog-export-labels":{"title":"Build export labels from mixed items","prompt":"The catalog app now needs export labels for storage. Finish the service so it works with mixed objects through the shared contract.\n\nTasks:\n- Keep `export_label()` in the base class and both subclasses.\n- In `services/export_service.py`, complete `join_labels(items)` so it returns one string with labels joined by ` | `.\n- The service must call `item.export_label()` on each object in the list.\n\nDo not change `main.py`. Click Run and check the output panel for the joined label string.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def export_label(self):\n return self.title"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def export_label(self):\n return f\"BOOK-{self.title}\""},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def export_label(self):\n return f\"VIDEO-{self.title}\""},"services_export_service_py":{"content":"def join_labels(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def export_label(self):\n return self.title"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def export_label(self):\n return f\"BOOK-{self.title}\""},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def export_label(self):\n return f\"VIDEO-{self.title}\""},"services_export_service_py":{"content":"def join_labels(items):\n labels = []\n for item in items:\n labels.append(item.export_label())\n return \" | \".join(labels)"}},"solutionCode":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))","checks":{"0":{"message":"join_labels() should join export labels from mixed items in order."}}}}},"inheritance-for-shared-behavior":{"label":"Inheritance for Shared Behavior","summary":"Use a parent class for genuinely shared state and behavior, then call `super().__init__` when a child constructor adds specialized state.","cards":{"sketch0":{"title":"Inherit shared setup and behavior"},"sketch1":{"title":"Add child state with super()"},"sketch2":{"title":"Extend a parent method"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_inheritance_for_shared_behavior_sketch0":{"title":"Make Book inherit shared behavior","prompt":"`CatalogItem` already owns the shared `title` constructor and `label()` method. In `models/book.py`, make `Book` inherit from `CatalogItem`. Do not add a `Book.__init__` or `Book.label()` yet; this exercise is about reusing the parent's existing setup and behavior. Leave `main.py` and `models/catalog_item.py` unchanged.","hint":"Put the parent class in parentheses in the `Book` class header.","help":{"concept":"A child class inherits available parent behavior. With no child constructor or label method, `Book` can use the parent's versions.","hint_1":"The parent class is `CatalogItem`.","hint_2":"Change only the `Book` class header; keep the body as `pass`."},"starterCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n# Make Book inherit from CatalogItem.\nclass Book:\n pass\n"}},"solutionCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n pass\n"}},"checks":{"0":{"message":"Keep `Book` defined in `models/book.py`."},"1":{"message":"The inherited parent constructor should make `Book(title)` constructible."},"2":{"message":"A `Book` should inherit the parent's `title` state."},"3":{"message":"A `Book` should inherit the parent's `label()` behavior."}},"expectedOutput":"Dune","sourceChecks":{"0":{"message":"Make `Book` inherit from `CatalogItem` in the class header."}}},"try_inheritance_for_shared_behavior_sketch1":{"title":"Add Book-specific state with super()","prompt":"`Book` already inherits from `CatalogItem`. In `models/book.py`, define `__init__(self, title, author)`. Call `super().__init__(title)` so the parent owns the shared title setup, then store the Book-specific author on `self.author`. Do not duplicate `self.title = title` inside `Book`. Leave `main.py` and `models/catalog_item.py` unchanged.","hint":"Let the parent initialize the shared title first, then store only the child-specific author.","help":{"concept":"`super().__init__` lets a child constructor reuse parent setup instead of copying the parent's initialization logic.","hint_1":"Call the parent constructor with the shared `title` value.","hint_2":"After the super call, assign `author` to `self.author`."},"starterCode":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n # Call the parent constructor for the shared title setup.\n # Then store the Book-specific author.\n pass\n"}},"solutionCode":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n"}},"checks":{"0":{"message":"Keep `Book` defined in `models/book.py`."},"1":{"message":"`Book` should accept both shared title and child-specific author state."},"2":{"message":"The finished `Book` should contain both inherited title and author state."},"3":{"message":"The constructor should work for other valid book data too."},"4":{"message":"Inherited and child-specific state should remain available on unseen data."}},"expectedOutput":"The Martian\nAndy Weir","sourceChecks":{"0":{"message":"Keep `Book` inheriting from `CatalogItem`."},"1":{"message":"Call `super().__init__(title)` for the shared parent setup."},"2":{"message":"Store the child-specific `author` on `self.author`."}}},"try_inheritance_for_shared_behavior_sketch2":{"title":"Extend a parent method with super()","prompt":"Add `label(self)` to `Book`. Start with `base_label = super().label()`, then return `f\"{base_label} by {self.author}\"`. In `main.py`, create `Book(\"The Hobbit\", \"J. R. R. Tolkien\")` and print its label.","hint":"Call `super().label()` to reuse the parent result before adding the author.","help":{"concept":"A child can override a method and still reuse the parent implementation. `super().label()` gets the parent result; the child adds its specialized detail.","hint_1":"Keep the Book constructor that calls `super().__init__(title)`.","hint_2":"Return the parent label followed by ` by ` and the author."},"starterCode":"from models.book import Book\n\n# Create The Hobbit and print the extended label.\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\n# Create Book(\"The Hobbit\", \"J. R. R. Tolkien\").\n# Print book.label().\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def label(self):\n # TODO: reuse the parent label and add the author.\n pass\n"}},"solutionCode":"from models.book import Book\n\nbook = Book(\"The Hobbit\", \"J. R. R. Tolkien\")\nprint(book.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\nbook = Book(\"The Hobbit\", \"J. R. R. Tolkien\")\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def label(self):\n base_label = super().label()\n return f\"{base_label} by {self.author}\"\n"}},"checks":{"0":{"message":"Book should accept title and author."},"1":{"message":"Book.label() should extend the parent label with the author."},"2":{"message":"Create the Book object in main.py."},"3":{"message":"Print the extended label."}},"expectedOutput":"The Hobbit by J. R. R. Tolkien"}},"practice":{"sc-inheritance-shared-work":{"title":"When does a parent class help?","prompt":"When is inheritance a good fit for shared setup?","hint":"Use a parent for behavior or state that is genuinely common to related child classes.","help":{"concept":"Inheritance is useful when related classes can reuse meaningful shared state or behavior.","hint_1":"The shared code should belong naturally to the parent concept.","hint_2":"Do not introduce inheritance just to avoid a few unrelated lines."},"options":{"a":"Whenever two unrelated classes happen to contain the same number of lines.","b":"When related classes genuinely share state or behavior that belongs in one parent.","c":"Whenever every child must eventually produce identical output.","d":"Only when no objects will ever be created."}},"fb-inheritance-subclass-name":{"title":"Reuse the parent constructor","prompt":"Complete the child constructor so it delegates the shared `title` setup to the parent.","hint":"Use the function that gives access to the next implementation in the inheritance chain.","help":{"concept":"`super()` lets the child reuse parent initialization without naming or copying the parent implementation.","hint_1":"The call is followed by `.__init__(title)`.","hint_2":"Include the parentheses in `super()`."},"template":"[blank1].__init__(title)","choices":["super()","self","CatalogItem()","parent"]},"dr-inheritance-build-order":{"title":"Order a child constructor","prompt":"Put these steps in a clear order.","hint":"Connect the child to the parent before adding child-only state.","help":{"concept":"The child class inherits first, then its constructor calls the parent setup, then it stores specialized state.","hint_1":"The class header comes first.","hint_2":"Call super before using the completed object."},"tokens":{"t1":"Define the child class with the parent in parentheses","t2":"Define the child constructor","t3":"Call `super().__init__(...)` for shared setup","t4":"Store the child-specific attributes"}},"sc-inheritance-method-reuse":{"title":"Place shared and specialized state","prompt":"`CatalogItem` stores `title`, while only `Book` has an `author`. Which design best matches those responsibilities?","hint":"Put genuinely shared state on the parent and child-only state on the child.","help":{"concept":"A parent owns shared state; a child adds only the state or behavior that makes it more specific.","hint_1":"Every catalog item needs a title.","hint_2":"Only books need the author field in this example."},"options":{"a":"Store both title and author only on `CatalogItem`, even for non-books.","b":"Store title independently in every child and leave the parent empty.","c":"Let `CatalogItem` initialize title, then let `Book` add author after calling `super().__init__(title)`.","d":"Put both values in `main.py` and keep them off the objects."}},"ci-inheritance-mixed-count-service":{"title":"Count mixed catalog items with one shared method","prompt":"You are building a quick inventory summary. `Book` and `Movie` should both inherit from `CatalogItem`, and `CatalogItem` should define `is_available()` that returns `True` when `stock > 0`. In `services/inventory_service.py`, complete `count_available(items)` so it returns how many objects in the mixed list are available. In `main.py`, use `Book(\"Dune\", 3)` and `Movie(\"Arrival\", 0)` and print the count. This matters because one shared base method lets a service work across different subclasses.","hint":"Give both subclasses the same inherited availability rule, then count how many return `True`.","help":{"concept":"A shared base-class method creates a common contract for subclasses. Services can then loop through mixed objects and call the same method on each one.","hint_1":"`is_available()` should check the stored `stock` value in the base class.","hint_2":"In the service function, increase the count only when `item.is_available()` is true."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title, stock):\n self.title = title\n self.stock = stock\n\n def is_available(self):\n return self.stock > 0"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n pass"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n pass"},"services_inventory_service_py":{"content":"def count_available(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title, stock):\n self.title = title\n self.stock = stock\n\n def is_available(self):\n return self.stock > 0"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n pass"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n pass"},"services_inventory_service_py":{"content":"def count_available(items):\n return sum(1 for item in items if item.is_available())"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))","checks":{"0":{"message":"Book should inherit is_available() and return True when stock is above zero."},"1":{"message":"Movie should inherit is_available() and return False when stock is zero."},"2":{"message":"count_available(items) should count available objects in a mixed list."}}},"ci-inheritance-shared-price-method":{"title":"Share a discount method through inheritance","prompt":"You are updating prices in a shop catalog. In `models/base_item.py`, complete `CatalogItem` so it stores `title` and `price`, and add `discounted_price(percent)` that returns the reduced price. In `models/book.py`, make `Book` inherit from `CatalogItem` and add `author`. In `main.py`, create `Book(\"Clean Code\", 30, \"Robert C. Martin\")` and print the result of `discounted_price(20)`. This matters because shared business rules belong in the base class instead of being copied into every subclass.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n"},"models_base_item_py":{"content":"class CatalogItem:\n def __init__(self, title, price):\n pass\n\n def discounted_price(self, percent):\n pass\n"},"models_book_py":{"content":"from models.base_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, price, author):\n pass\n"}},"solutionCode":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n"},"models_base_item_py":{"content":"class CatalogItem:\n def __init__(self, title, price):\n self.title = title\n self.price = price\n\n def discounted_price(self, percent):\n return self.price * (1 - percent / 100)\n"},"models_book_py":{"content":"from models.base_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, price, author):\n super().__init__(title, price)\n self.author = author\n"}},"sourceChecks":{"0":{"message":"Make `Book` inherit from `CatalogItem` in the class header."}},"checks":{"0":{"message":"Define CatalogItem in models/base_item.py."},"1":{"message":"Define Book in models/book.py."},"2":{"message":"A Book should inherit discounted_price() from CatalogItem and calculate the reduced price correctly."}}},"practice-inherit-shared-label":{"title":"Inherit a shared label method","prompt":"Define a base class `Vehicle` that stores `name` and has `label()` returning `Vehicle: <name>`. Define `Bike(Vehicle)` without rewriting `label()`. Create `Bike(\"Comet\")` and print its inherited label.","hint":"The subclass can use the base constructor and method without defining them again.","help":{"concept":"Inheritance lets a subclass reuse behavior that is genuinely shared with its base class.","hint_1":"The subclass can use the base constructor and method without defining them again.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Vehicle:\n def __init__(self, name):\n # store the shared name\n pass\n\n def label(self):\n # return Vehicle: <name>\n pass\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n","starterFiles":{"main_py":{"content":"class Vehicle:\n def __init__(self, name):\n # store the shared name\n pass\n\n def label(self):\n # return Vehicle: <name>\n pass\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n"}},"solutionCode":"class Vehicle:\n def __init__(self, name):\n self.name = name\n\n def label(self):\n return f\"Vehicle: {self.name}\"\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n","solutionFiles":{"main_py":{"content":"class Vehicle:\n def __init__(self, name):\n self.name = name\n\n def label(self):\n return f\"Vehicle: {self.name}\"\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n"}}}}},"module-9-greenhouse-sensor-project":{"label":"Module 9 Greenhouse Sensor Project","summary":"Build a greenhouse monitor that lets temperature and humidity sensors share one contract and one reporting flow.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Greenhouse Sensor Monitor"}},"projectSteps":{"greenhouse_project_step_1_base_and_temperature":{"title":"Milestone 1: Build the Sensor contract"},"greenhouse_project_step_2_add_humidity_override":{"title":"Milestone 2: Add HumiditySensor"},"greenhouse_project_step_3_mixed_sensor_loop":{"title":"Milestone 3: Use one polymorphic sensor loop"},"greenhouse_project_step_4_monitor_class_report":{"title":"Milestone 4: Give the monitor collection ownership"}},"moduleProject":{"steps":{"greenhouse_project_step_1_base_and_temperature":{"title":"Milestone 1: build the abstract Sensor contract","prompt":"Complete the first greenhouse milestone. In `models/sensor.py`, make `Sensor` inherit from `ABC`, keep the constructor that stores `zone`, and make `reading(self)` an `@abstractmethod`. In `models/temperature_sensor.py`, keep `TemperatureSensor(Sensor)`, call `super().__init__(zone)`, store `celsius`, and implement `reading()` so it returns `Temperature: <zone> = <value> C`. In `main.py`, create the sensor from the provided input values and print its reading. Leave the future humidity/monitor placeholder files unchanged.","hint":"Retrieve the patterns from the inheritance and ABC lessons: the parent owns shared `zone` setup; the concrete child supplies `reading()`.","help":{"concept":"This milestone combines an enforceable abstract contract with shared parent setup and one concrete implementation.","hint_1":"Import `ABC` and `abstractmethod` from `abc`.","hint_2":"Use `super().__init__(zone)` instead of copying `self.zone = zone` into the child."},"starterCode":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\n# Create the TemperatureSensor and print its reading.\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\n# Create the TemperatureSensor and print its reading.\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"# Make Sensor an abstract base class with a required reading() method.\nclass Sensor:\n def __init__(self, zone):\n self.zone = zone\n\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n # Reuse Sensor's zone setup, then store celsius.\n pass\n\n def reading(self):\n # Return: Temperature: <zone> = <celsius> C\n pass\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"}},"checks":{"0":{"message":"TemperatureSensor should be concrete and constructible."},"1":{"message":"Keep shared `zone` state and child-specific `celsius` state."},"2":{"message":"TemperatureSensor.reading() must use the object's actual state."},"3":{"message":"TemperatureSensor.reading() must work for other valid readings."},"4":{"message":"TemperatureSensor should accept zone and celsius."},"5":{"message":"TemperatureSensor should store its state and return the expected reading."}},"expectedOutput":"Temperature: North Bed = 21.5 C","sourceChecks":{"0":{"message":"Import both `ABC` and `abstractmethod` from `abc`."},"1":{"message":"Make `Sensor` inherit from `ABC`."},"2":{"message":"Make `reading(self)` an abstract method."},"3":{"message":"Keep `TemperatureSensor` inheriting from `Sensor`."},"4":{"message":"Reuse the parent constructor with `super().__init__(zone)`."},"5":{"message":"Implement the concrete `reading(self)` method."}}},"greenhouse_project_step_2_add_humidity_override":{"title":"Milestone 2: add a second concrete sensor","prompt":"Continue from the exact Milestone 1 workspace. Complete `models/humidity_sensor.py` with `HumiditySensor(Sensor)`. Its constructor must call `super().__init__(zone)` and store `percent`; `reading(self)` must return `Humidity: <zone> = <percent>%`. Update `main.py` to read the provided temperature and humidity values, create both sensor objects, and print both readings. Keep the existing `Sensor` and `TemperatureSensor` implementations unchanged.","hint":"HumiditySensor follows the same inherited setup contract as TemperatureSensor, but owns different child state and output.","help":{"concept":"Sibling subclasses can reuse the same parent setup while specializing the same required method.","hint_1":"Use `class HumiditySensor(Sensor)`.","hint_2":"Call `super().__init__(zone)` before storing `percent`."},"starterCode":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"# Added in Milestone 2.\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"}},"checks":{"0":{"message":"Keep the completed TemperatureSensor behavior working."},"1":{"message":"HumiditySensor should be concrete and constructible."},"2":{"message":"Keep shared `zone` state and child-specific `percent` state."},"3":{"message":"HumiditySensor.reading() must use the object's actual state."},"4":{"message":"HumiditySensor.reading() must work for other valid readings."}},"expectedOutput":"Temperature: North Bed = 21.5 C\nHumidity: Seedling Bench = 64%","sourceChecks":{"0":{"message":"Make `HumiditySensor` inherit from `Sensor`."},"1":{"message":"Reuse the shared parent setup with `super().__init__(zone)`."},"2":{"message":"Implement the humidity-specific `reading(self)` method."}}},"greenhouse_project_step_3_mixed_sensor_loop":{"title":"Milestone 3: use one polymorphic sensor loop","prompt":"Continue from the exact Milestone 2 workspace. In `main.py`, replace the two separate sensor variables/print calls with one `sensors` list containing the `TemperatureSensor` and `HumiditySensor`. Use one `for` loop over `sensors` and call the current object's shared `reading()` method. Do not branch with `isinstance()`, `type()`, `__class__`, or separate Temperature/Humidity cases. Keep all model files unchanged.","hint":"The caller should trust the `reading()` contract instead of asking which sensor subclass it received.","help":{"concept":"This milestone retrieves branch-free polymorphism: different objects, one shared method contract, one caller.","hint_1":"Create one mixed `sensors = [...]` list.","hint_2":"Inside the loop, use `sensor.reading()`."},"starterCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"}},"checks":{"0":{"message":"Keep TemperatureSensor's specialized behavior working."},"1":{"message":"Keep HumiditySensor's specialized behavior working."},"2":{"message":"TemperatureSensor.reading() should still return the expected reading."},"3":{"message":"HumiditySensor.reading() should still return the expected reading."},"4":{"message":"Print both readings from one shared loop."}},"expectedOutput":"Temperature: North Bed = 21.5 C\nHumidity: Seedling Bench = 64%","sourceChecks":{"0":{"message":"Use one `for` loop over the mixed `sensors` collection."},"1":{"message":"Call the shared `reading()` method inside the loop without concrete-type branching."}}},"greenhouse_project_step_4_monitor_class_report":{"title":"Milestone 4: give GreenhouseMonitor collection ownership","prompt":"Continue from the exact Milestone 3 workspace. Complete `models/greenhouse_monitor.py`. `GreenhouseMonitor.__init__()` must create an empty `self.sensors` list; `add_sensor(self, sensor)` must append the object; and `print_report(self)` must use one loop over `self.sensors` and print each object's shared `reading()` result. Update `main.py` so it creates the monitor, adds the temperature and humidity sensors, and calls `monitor.print_report()`. Do not branch on sensor types. Keep the completed Sensor subclasses unchanged.","hint":"Retrieve the responsibility boundary from Module 8: the monitor owns the collection; each sensor still owns how its own reading is formatted.","help":{"concept":"The final class owns collection coordination while remaining polymorphic—it depends only on each object's `reading()` behavior.","hint_1":"Initialize `self.sensors = []`.","hint_2":"Append in `add_sensor()` and call `sensor.reading()` inside one report loop."},"starterCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"},"models_greenhouse_monitor_py":{"content":"# Added in Milestone 4.\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\nfrom models.greenhouse_monitor import GreenhouseMonitor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nmonitor = GreenhouseMonitor()\nmonitor.add_sensor(TemperatureSensor(temperature_zone, celsius))\nmonitor.add_sensor(HumiditySensor(humidity_zone, percent))\nmonitor.print_report()\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\nfrom models.greenhouse_monitor import GreenhouseMonitor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nmonitor = GreenhouseMonitor()\nmonitor.add_sensor(TemperatureSensor(temperature_zone, celsius))\nmonitor.add_sensor(HumiditySensor(humidity_zone, percent))\nmonitor.print_report()\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"},"models_greenhouse_monitor_py":{"content":"class GreenhouseMonitor:\n def __init__(self):\n self.sensors = []\n\n def add_sensor(self, sensor):\n self.sensors.append(sensor)\n\n def print_report(self):\n for sensor in self.sensors:\n print(sensor.reading())\n"}},"checks":{"0":{"message":"GreenhouseMonitor should be constructible without arguments."},"1":{"message":"Each monitor should own a `sensors` collection."},"2":{"message":"Keep the temperature subclass working after the monitor refactor."},"3":{"message":"Keep the humidity subclass working after the monitor refactor."}},"expectedOutput":"Temperature: North Bed = 21.5 C\nHumidity: Seedling Bench = 64%","sourceChecks":{"0":{"message":"Define `GreenhouseMonitor` in its model file."},"1":{"message":"Give each monitor its own empty `sensors` list."},"2":{"message":"`add_sensor()` should append the object it receives."},"3":{"message":"`print_report()` should use one shared `reading()` call without concrete-type branching."}}}}}},"overriding-and-specialization":{"label":"Overriding and Specialization","summary":"Override inherited behavior by keeping the same public method name while a subclass supplies a more specific implementation.","cards":{"sketch0":{"title":"Override inherited behavior"},"sketch1":{"title":"Override the method in one subclass"},"sketch2":{"title":"Specialize more than one subclass"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_overriding_and_specialization_sketch0":{"title":"Override label() on Book","prompt":"`Book` already inherits from `CatalogItem`, and `main.py` is complete. In `models/book.py`, override the inherited `label(self)` method so a `Book` returns `Book: ` followed by that object's title. Keep the method name `label`, keep `Book` inheriting from `CatalogItem`, and leave `models/catalog_item.py` and `main.py` unchanged.","hint":"Define `label(self)` inside `Book`. The child method should use `self.title` and return the specialized text.","help":{"concept":"An override uses the same method name as the inherited method but provides subclass-specific behavior.","hint_1":"Keep `class Book(CatalogItem)` unchanged.","hint_2":"Define `label(self)` directly inside `Book` and use `self.title`."},"starterCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n # Override label() here.\n pass\n"}},"solutionCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"}},"checks":{"0":{"message":"Keep the parent `CatalogItem.label()` behavior unchanged."},"1":{"message":"`Book.label()` should specialize the visible title."},"2":{"message":"`Book.label()` should use the object's actual title, not a hard-coded example."},"3":{"message":"The override should work for other valid titles too."}},"expectedOutput":"Book: Project Hail Mary","sourceChecks":{"0":{"message":"Keep `Book` inheriting from `CatalogItem` so `label()` is a real override."},"1":{"message":"Define `label(self)` directly on `Book`."}}},"try_overriding_and_specialization_sketch1":{"title":"Override label() for Movie","prompt":"Use the same overriding pattern with another catalog type. In `models/movie.py`, override `label()` so `Movie(\"Inside Out\")` returns `Movie: Inside Out`. Then finish `main.py` by creating the movie and printing its label.","hint":"Book and Movie should both use `label()`, but each one can return a different kind of label.","help":{"concept":"Two subclasses can share a method name while producing different results. That sets up polymorphism in the next topic.","hint_1":"The method name should still be `label()`.","hint_2":"Return `Movie: ` followed by `self.title`."},"starterCode":"from models.movie import Movie\n\n# TODO: create Movie(\"Inside Out\").\n# TODO: print the movie label.\n","starterFiles":{"main_py":{"content":"from models.movie import Movie\n\n# TODO: create Movie(\"Inside Out\").\n# TODO: print the movie label.\n"},"models_catalog_item_py":{"content":"# Keep models/catalog_item.py unchanged for this step: Override label() for Movie.\nclass CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Movie(CatalogItem):\n # TODO: override label() so it returns \"Movie: <title>\".\n pass\n"}},"solutionCode":"from models.movie import Movie\n\nmovie = Movie(\"Inside Out\")\nprint(movie.label())\n","solutionFiles":{"main_py":{"content":"from models.movie import Movie\n\nmovie = Movie(\"Inside Out\")\nprint(movie.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"Movie.label() should return the movie-specific label."}},"expectedOutput":"Movie: Inside Out"},"try_overriding_and_specialization_sketch2":{"title":"Print both specialized labels","prompt":"Now use both specialized child classes. The `Book` and `Movie` classes are provided. In `main.py`, create `Book(\"Coraline\")` and `Movie(\"Coco\")`, then print each object's `label()` result on its own line.","hint":"Create one Book and one Movie. Call `.label()` on each object.","help":{"concept":"The call looks the same for both objects, but each subclass decides what its own label should look like.","hint_1":"Use `book.label()` for the first line.","hint_2":"Use `movie.label()` for the second line."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\n\n# TODO: create a Book for \"Coraline\".\n# TODO: create a Movie for \"Coco\".\n# TODO: print each object's label on its own line.\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\n# TODO: create a Book for \"Coraline\".\n# TODO: create a Movie for \"Coco\".\n# TODO: print each object's label on its own line.\n"},"models_catalog_item_py":{"content":"# Keep models/catalog_item.py unchanged for this step: Print both specialized labels.\nclass CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"# Keep models/book.py unchanged for this step: Print both specialized labels.\nfrom models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"# Keep models/movie.py unchanged for this step: Print both specialized labels.\nfrom models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\n\nbook = Book(\"Coraline\")\nmovie = Movie(\"Coco\")\nprint(book.label())\nprint(movie.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\nbook = Book(\"Coraline\")\nmovie = Movie(\"Coco\")\nprint(book.label())\nprint(movie.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"Book.label() should stay specialized."},"1":{"message":"Movie.label() should stay specialized."}},"expectedOutput":"Book: Coraline\nMovie: Coco"}},"practice":{"sc-overriding-purpose":{"title":"Why override an inherited method?","prompt":"`CatalogItem.label()` returns only the title. Why should `Book` override `label()` instead of inventing a different method name?","hint":"The caller should keep using the same public behavior.","help":{"concept":"Overriding preserves the inherited method contract while allowing the subclass to specialize its implementation.","hint_1":"The method name stays `label`.","hint_2":"The child can return a more specific result."},"options":{"a":"To stop `Book` from inheriting from `CatalogItem`","b":"To force callers to learn a new method name for every subclass","c":"To keep the `label()` contract while giving `Book` book-specific behavior","d":"To remove the title state inherited from `CatalogItem`"}},"fb-overriding-method-name":{"title":"Keep the inherited method name","prompt":"Complete the method name so `Book` overrides the method it inherits from `CatalogItem`.","hint":"An override uses the same method name as the parent.","help":{"concept":"Python recognizes the subclass implementation as an override because it uses the same method name.","hint_1":"The parent method is named `label`.","hint_2":"Do not rename it to `book_label`."},"template":"class Book(CatalogItem):\n def [blank1](self):\n return f\"Book: {self.title}\"","choices":["label","book_label","title","__init__"]},"dr-overriding-workflow":{"title":"Order the override steps","prompt":"Put the beginner workflow in order.","hint":"Begin with the base method, then specialize it in subclasses.","help":{"concept":"It is easiest to override after the base behavior already exists.","hint_1":"The shared method comes first.","hint_2":"Printing the result comes after the subclass method is ready."},"tokens":{"t1":"Write `label()` in CatalogItem","t2":"Create `Book.label()` with a book-specific return value","t3":"Create `Movie.label()` with a movie-specific return value","t4":"Make objects and print both labels"}},"sc-overriding-shared-contract":{"title":"Which label() runs?","prompt":"`CatalogItem.label()` returns `self.title`, while `Book.label()` returns `Book: ` plus the title. What does `Book(\"Coraline\").label()` return?","hint":"Python looks on the subclass before falling back to the parent.","help":{"concept":"When a subclass overrides a method, calls on that subclass use the subclass implementation.","hint_1":"`Book` defines its own `label()`.","hint_2":"The result includes the `Book: ` prefix."},"options":{"a":"Coraline","b":"Book: Coraline","c":"CatalogItem: Coraline","d":"Python raises an error because both classes define `label()`"}},"catalog-step-book-and-movie":{"title":"Specialize labels for two catalog subclasses","prompt":"You are extending a media catalog. The base `CatalogItem` already stores `title`. Complete both subclasses so they reuse the parent constructor and override `display_name()`: `BookItem` should return `\"<title> by <author>\"`, and `MovieItem` should return `\"<title> (<minutes> min)\"`. The workspace already includes a small `main.py` that prints both labels.","hint":"Both subclasses share the same method name, but each one formats the result differently.","help":{"concept":"Different subclasses can override the same base method in different ways while still fitting the same base-class contract.","hint_1":"Use `super().__init__(title)` in both subclass constructors before storing the extra field.","hint_2":"Write one `display_name()` method in each subclass, each returning its own specialized string format."},"starterCode":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())","starterFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n pass"},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n return f\"{self.title} by {self.author}\""},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n return f\"{self.title} ({self.minutes} min)\""}},"solutionCode":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())","checks":{"0":{"message":"Define a BookItem class."},"1":{"message":"Define a MovieItem class."},"2":{"message":"BookItem.display_name() should return the book label."},"3":{"message":"MovieItem.display_name() should return the movie label."}}},"catalog-step-mixed-report":{"title":"Build a report from mixed specialized items","prompt":"Build a mixed catalog report without checking object types manually. The workspace includes a base `CatalogItem` plus `BookItem` and `MovieItem` subclasses that all provide `display_name()`. Complete `build_display_report(items)` in `services/reporting.py` so it returns each item's display label in order. `main.py` will print the returned lines.","hint":"Loop through the mixed list and call the same `display_name()` method on every item.","help":{"concept":"Polymorphic services work by calling the same method on mixed related objects, while overriding lets each subclass provide its own specialized output.","hint_1":"Make sure each subclass overrides `display_name()` correctly before writing the service loop.","hint_2":"In the service function, iterate through `items` and append `item.display_name()` for each object in order."},"starterCode":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n return f\"{self.title} by {self.author}\""},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n return f\"{self.title} ({self.minutes} min)\""},"services_reporting_py":{"content":"def build_display_report(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n return f\"{self.title} by {self.author}\""},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n return f\"{self.title} ({self.minutes} min)\""},"services_reporting_py":{"content":"def build_display_report(items):\n return [item.display_name() for item in items]"}},"solutionCode":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)"},"practice-specialized-display-label":{"title":"Override a display label in one subclass","prompt":"Define a base class `MediaItem` that stores `title` and has `display()` returning `Item: <title>`. Define `Song(MediaItem)` and override `display()` so it returns `Song: <title>`. Print the display text for one base item and one song.","hint":"Keep the shared version on the base class, then redefine only `display()` inside `Song`.","help":{"concept":"Overriding lets a subclass specialize one inherited behavior while keeping the rest of the shared base-class structure.","hint_1":"Keep the shared version on the base class, then redefine only `display()` inside `Song`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n # return Item: <title>\n pass\n\nclass Song(MediaItem):\n def display(self):\n # return Song: <title>\n pass\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n","starterFiles":{"main_py":{"content":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n # return Item: <title>\n pass\n\nclass Song(MediaItem):\n def display(self):\n # return Song: <title>\n pass\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n"}},"solutionCode":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n return f\"Item: {self.title}\"\n\nclass Song(MediaItem):\n def display(self):\n return f\"Song: {self.title}\"\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n","solutionFiles":{"main_py":{"content":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n return f\"Item: {self.title}\"\n\nclass Song(MediaItem):\n def display(self):\n return f\"Song: {self.title}\"\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n"}}}}},"polymorphic-collections":{"label":"Polymorphic Collections","summary":"Use one shared method call across mixed objects so callers do not need type-specific branches.","cards":{"sketch0":{"title":"One loop, one shared method"},"sketch1":{"title":"Move the shared contract into a service"},"sketch2":{"title":"Move the loop into a helper"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_polymorphic_collections_sketch0":{"title":"Use one loop for Book and Movie","prompt":"`catalog` already contains one `Book` and one `Movie`, and both classes already provide `label()`. In `main.py`, use one `for` loop over `catalog`. Inside that loop, call the current object's shared `label()` method and print the returned label. Do not branch on the concrete type with `isinstance()`, `type()`, `__class__`, or separate Book/Movie cases.","hint":"The loop should trust the shared method. Each item can answer `label()` without the caller first asking what class it is.","help":{"concept":"Polymorphism lets one caller use the same method on different object types. The object itself chooses the appropriate implementation.","hint_1":"Loop directly over `catalog`.","hint_2":"Inside the loop, use the current object's `label()` result."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\n# Use one for loop over catalog.\n# Call the shared label() method for each item and print the result.\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\n# Use one for loop over catalog.\n# Call the shared label() method for each item and print the result.\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\nfor item in catalog:\n print(item.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\nfor item in catalog:\n print(item.label())\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"Keep the Book object in the mixed list."},"1":{"message":"Keep the Movie object in the mixed list."},"2":{"message":"Print both labels from the loop."}},"expectedOutput":"Book: Coraline\nMovie: Arrival","sourceChecks":{"0":{"message":"Use one `for` loop over `catalog` so the same caller handles both object types."},"1":{"message":"Inside that loop, print the current object's `label()` result without branching on its concrete type."}}},"try_polymorphic_collections_sketch1":{"title":"Build a polymorphic catalog-report service","prompt":"`main.py`, `Book`, and `Movie` are already complete. In `services/catalog_report.py`, complete `build_labels(items)` so it returns one list containing each object's `label()` result in the same order as the input collection. Use one `for` loop over `items` and the shared `label()` method. The service must not branch on concrete types with `isinstance()`, `type()`, `__class__`, or separate Book/Movie cases.","hint":"The service should know only that each item has `label()`. It should not need to know which concrete class supplied that method.","help":{"concept":"A polymorphic service depends on shared behavior. New compatible classes can be added without adding another type-specific branch.","hint_1":"Iterate over `items` and collect each item's `label()` result.","hint_2":"Return the finished list after the loop."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n\n # Use one for loop over items.\n # Add each object's label() result to labels.\n\n return labels\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n\n for item in items:\n labels.append(item.label())\n\n return labels\n"}},"checks":{"0":{"message":"Return both labels so main.py can print two lines."},"1":{"message":"Keep the Movie object in the mixed list."},"2":{"message":"Print both labels from the loop."}},"expectedOutput":"Book: Dune\nMovie: Arrival","sourceChecks":{"0":{"message":"`build_labels(items)` should use one shared `label()` call inside a loop and return the collected labels without concrete-type branches."}}},"try_polymorphic_collections_sketch2":{"title":"Return labels from a helper","prompt":"Complete `build_labels(items)` in `services/catalog_report.py`. It must loop through the supplied items, collect each `item.label()` result in order, and return the list. `main.py` is already wired to print the returned labels.","hint":"Start with an empty list, append `item.label()` inside a loop, and return the finished list.","help":{"concept":"A reusable helper can depend on the shared `label()` behavior without knowing whether an item is a Book or Movie.","hint_1":"Start with an empty list, append `item.label()` inside a loop, and return the finished list.","hint_2":"Use the requested file boundary as part of the solution contract."},"starterCode":"# Run this provided script after completing the helper.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n","starterFiles":{"main_py":{"content":"# Run this provided script after completing the helper.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"# Keep the provided Book model unchanged.\nclass Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"# Keep the provided Movie model unchanged.\nclass Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n # TODO: return a list containing item.label() for every item.\n pass\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n for item in items:\n labels.append(item.label())\n return labels\n"}},"checks":{"0":{"message":"Return both labels so main.py can print two lines."}},"expectedOutput":"Book: A Wrinkle in Time\nMovie: Up"}},"practice":{"sc-polymorphism-mixed-list":{"title":"Why use the shared method?","prompt":"A list contains `Book` and `Movie` objects, and both provide `label()`. What is the main polymorphic advantage?","hint":"Think about what the caller no longer needs to know.","help":{"concept":"Polymorphism lets the caller depend on shared behavior instead of branching on each concrete class.","hint_1":"The caller can make the same method call for every item.","hint_2":"The object decides which implementation runs."},"options":{"a":"Every object in the list must be the same concrete class","b":"One caller can use `label()` without checking whether an item is a Book or Movie","c":"Python automatically converts every object into the parent class","d":"The loop no longer needs to call any methods"}},"fb-polymorphism-shared-call":{"title":"Recognize polymorphic callers","prompt":"Which TWO designs rely on the shared `label()` behavior instead of concrete-type branching?","hint":"Choose callers that treat every compatible object through the same method.","help":{"concept":"A polymorphic caller asks for shared behavior. It does not need a separate Book path and Movie path.","hint_1":"A direct `item.label()` call is the shared contract.","hint_2":"Reject designs whose logic changes after checking the concrete class."},"template":"for item in catalog:\n print(item.[blank1]())","choices":["label","title","Book","super"],"options":{"a":"Loop through `catalog` and use each item's `label()` method","b":"Use `isinstance()` to choose a Book branch or Movie branch","c":"Pass the mixed collection to a helper that calls `label()` on each item","d":"Check `type(item)` and manually build a different label for every class"}},"dr-polymorphism-loop-order":{"title":"Order the loop steps","prompt":"Put these steps in order for a polymorphic helper.","hint":"Start with the list, then loop, then call the shared method.","help":{"concept":"A polymorphic helper follows a simple receive-loop-call-store pattern.","hint_1":"The list comes before the loop.","hint_2":"The append step happens after the method returns a value."},"tokens":{"t1":"Receive the mixed items list","t2":"Loop through each item","t3":"Call `item.label()`","t4":"Add the returned label to the results list"}},"sc-polymorphism-no-type-check":{"title":"Complete the shared call","prompt":"Complete the method name so the same loop works for every compatible object in `catalog`.","hint":"Use the method contract shared by Book and Movie.","help":{"concept":"The shared method name is what allows one loop to remain unaware of the concrete object type.","hint_1":"Both classes provide the same labeling behavior.","hint_2":"The loop should call `item.label()`."},"options":{"a":"Write a separate loop for every subclass forever","b":"Rename the method in each subclass so they are all different","c":"Check each object type before every method call","d":"Call the same method on each object in the mixed list"},"template":"for item in catalog:\n print(item.[blank1]())","choices":["label","book_label","movie_label","__class__"]},"project-polymorphic-collections-step4":{"title":"Add a new subclass without changing the service","prompt":"Add a `Magazine` object to a mixed collection that already contains book and video objects. Complete `Magazine.display_name()` so the same loop can call `display_name()` on every item and print three labels. The magazine label should be `Magazine: Science Weekly`.","hint":"Give `Magazine` the same method name used by the other objects in the collection.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())","starterFiles":{"main_py":{"content":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())"},"models_magazine_py":{"content":"class Magazine:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())"},"models_magazine_py":{"content":"class Magazine:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return f\"Magazine: {self.title}\""}},"solutionCode":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())"},"project-polymorphic-collections-step5":{"title":"Build a checkout summary from mixed rentals","prompt":"A rental desk stores book and movie rentals in the same list. Complete `checkout_line()` in both classes so one loop can print a line for each object without checking its type. Use the formats `Book rental: <title> (<days> days)` and `Movie rental: <title> (<days> days)`.","hint":"Both classes need the same method name, but each can format its own label.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())","starterFiles":{"main_py":{"content":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())"},"models_book_rental_py":{"content":"class BookRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n pass"},"models_movie_rental_py":{"content":"class MovieRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())"},"models_book_rental_py":{"content":"class BookRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n return f\"Book rental: {self.title} ({self.days} days)\""},"models_movie_rental_py":{"content":"class MovieRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n return f\"Movie rental: {self.title} ({self.days} days)\""}},"solutionCode":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())"},"project-polymorphic-collections-step6":{"title":"Create a stock alert service for mixed inventory items","prompt":"A store keeps book and supply objects in one inventory list. Complete each class's `alert_line()` method and `low_stock_lines(items)` so the service returns alerts only for objects whose `quantity` is below 3. The service should call the shared `alert_line()` method instead of checking item types.","hint":"Filter by the shared `quantity` attribute, then call `alert_line()` on each matching object.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)","starterFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)"},"models_book_item_py":{"content":"class BookItem:\n def __init__(self, title, quantity):\n self.title = title\n self.quantity = quantity\n\n def alert_line(self):\n pass"},"models_supply_item_py":{"content":"class SupplyItem:\n def __init__(self, name, quantity):\n self.name = name\n self.quantity = quantity\n\n def alert_line(self):\n pass"},"services_alert_service_py":{"content":"def low_stock_lines(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)"},"models_book_item_py":{"content":"class BookItem:\n def __init__(self, title, quantity):\n self.title = title\n self.quantity = quantity\n\n def alert_line(self):\n return f\"LOW STOCK: Book {self.title} has {self.quantity} left\""},"models_supply_item_py":{"content":"class SupplyItem:\n def __init__(self, name, quantity):\n self.name = name\n self.quantity = quantity\n\n def alert_line(self):\n return f\"LOW STOCK: Supply {self.name} has {self.quantity} left\""},"services_alert_service_py":{"content":"def low_stock_lines(items):\n return [item.alert_line() for item in items if item.quantity < 3]"}},"solutionCode":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)"}}}}},"python-data-functions":{"python-5-lists-tuples-and-dictionaries":{"creating-and-indexing-lists":{"label":"Creating and Indexing Lists","summary":"Create ordered lists and read items with positive and negative indexes.","cards":{"course-introduction":{"title":"Course introduction"},"sketch0":{"title":"Creating lists"},"sketch1":{"title":"Reading items by index"},"sketch2":{"title":"Reading from the end"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-first-index":{"title":"First item index","prompt":"Which index gets the first item from a Python list?","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"0","b":"1","c":"-1","d":"first"}},"sc-whole-list":{"title":"Create a list","prompt":"Which line correctly creates a Python list containing the numbers 3, 5, and 7 in that order?","hint":"Python list literals use square brackets and commas.","help":{"concept":"A list literal uses square brackets around comma-separated items.","hint_1":"Look at the outer punctuation around the three values.","hint_2":"Choose the option written as `[3, 5, 7]`."},"options":{"a":"numbers = [3, 5, 7]","b":"numbers = (3, 5, 7)","c":"numbers = {3, 5, 7}","d":"numbers = \"3, 5, 7\""}},"mc-valid-index-expressions":{"title":"Valid list access","prompt":"Choose all expressions that correctly access an item from `letters = [\"a\", \"b\", \"c\"]`.","hint":"A valid access uses the list name followed by an index in square brackets.","help":{"concept":"To access a list item, Python uses the syntax `list_name[index]` with a numeric index.","hint_1":"Check which choices use square brackets after `letters`.","hint_2":"Two choices use the correct indexing pattern and refer to real positions in this three-item list."},"options":{"a":"letters[0]","b":"letters[2]","c":"letters(1)"}},"mc-true-about-lists":{"title":"Facts about lists","prompt":"Choose all true statements about Python lists.","hint":"Compare the options with the exact syntax and result required by the prompt.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"Lists keep items in order.","b":"The first item in a list has index 0.","c":"Lists must contain only numbers.","d":"Square brackets are used to create lists."}},"dr-build-list-line":{"title":"Build the list line","prompt":"Put the tokens in order to create a line of code that stores `\"pen\"`, `\"pencil\"`, and `\"eraser\"` in a list named `items`.","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"tokens":{"t1":"items","t2":"=","t3":"[","t4":"\"pen\"","t5":",","t6":"\"pencil\"","t7":"\"eraser\"","t8":"]"}},"dr-index-output-order":{"title":"Trace indexed output","prompt":"A program runs this code:\n\n`colors = [\"red\", \"blue\", \"green\"]`\n`print(colors[2])`\n`print(colors[0])`\n`print(colors[1])`\n\nArrange the printed lines in the order they appear.","hint":"Resolve each index before ordering the three printed values.","help":{"concept":"Index 0 is the first item, index 1 is the second, and index 2 is the third.","hint_1":"Work through the three `print()` calls from top to bottom.","hint_2":"The calls read indexes 2, 0, then 1."},"tokens":{"t1":"green","t2":"red","t3":"blue"}},"fb-second-item":{"title":"Read the second item","prompt":"Complete the code so it prints the second item in `letters`.","hint":"Python starts list indexes at 0.","help":{"concept":"The first three list positions use indexes 0, 1, and 2.","hint_1":"If the first item is index 0, move forward one index to reach the second item.","hint_2":"Use index `1`."},"template":"letters = [\"a\", \"b\", \"c\"]\nprint(letters[[blank1]])","choices":["0","1","2","3"]},"fb-list-name":{"title":"Complete the list assignment","prompt":"Choose the missing variable name so the list is stored in `numbers`.","hint":"Only the name before `=` is missing.","help":{"concept":"In an assignment, the variable name goes on the left side of `=` and receives the list value on the right.","hint_1":"The blank should be the variable that will hold `[4, 8, 12]`.","hint_2":"Pick the choice that is a sensible variable name, not a keyword or function."},"template":"[blank1] = [4, 8, 12]","choices":["numbers","print","index","list()"]},"ci-print-first-last":{"title":"Print the first and last list items","prompt":"Three fruit labels come in one at a time. Store the inputs in a list, then print the first fruit and the last fruit on separate lines.\n\nFor example, if the inputs are `apple`, `banana`, and `cherry`, your program should print:\n`apple`\n`cherry`.","hint":"Read the task \"Print the first and last list items\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"word1 = input()\nword2 = input()\nword3 = input()\n\n# Store the words in a list.\n# Then print the first item and the last item on separate lines.","solutionCode":"word1 = input()\nword2 = input()\nword3 = input()\n\nwords = [word1, word2, word3]\nprint(words[0])\nprint(words[2])","sourceChecks":{"0":{"message":"Use index 0 to read the first item instead of printing the input directly."},"1":{"message":"Use an index to read the last item from the list."}}},"ci-print-second-number":{"title":"Print the second number","prompt":"A scoreboard sends three numbers in order. Put them into a list, then print the second item from that list.\n\nFor example, if the inputs are `4`, `9`, and `2`, your program should print:\n`9`.","hint":"The second item in a list is at index 1.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\n\n# Put the numbers into a list.\n# Print the second item.","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\n\nnumbers = [a, b, c]\nprint(numbers[1])","sourceChecks":{"0":{"message":"Use index 1 to read the second item from the list."}}},"ci-build-and-show-list":{"title":"Build a list from input","prompt":"A paint shelf needs a quick inventory. Collect the three input colors into one list and print the finished list.\n\nFor example, if the inputs are `red`, `blue`, and `green`, your program should print:\n`['red', 'blue', 'green']`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"color1 = input()\ncolor2 = input()\ncolor3 = input()\n\n# Create a list with the three colors.\n# Print the whole list.","solutionCode":"color1 = input()\ncolor2 = input()\ncolor3 = input()\n\ncolors = [color1, color2, color3]\nprint(colors)","sourceChecks":{"0":{"message":"Create a list with color1, color2, and color3 before printing it."}}},"try-creating-and-indexing-lists-checkpoint":{"title":"Index and print list values","prompt":"Create the list `[\"Ava\", \"Mia\", \"Zoe\"]`. Print the first name, then print the last name.","hint":"Use index `0` for the first item and `-1` for the last item.","help":{"concept":"List indexing lets you retrieve a value by position.","hint_1":"Use index `0` for the first item and `-1` for the last item.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"names = []\n\n# Create the list [\"Ava\", \"Mia\", \"Zoe\"].\n# Print the first name, then print the last name.\n","solutionCode":"names = [\"Ava\", \"Mia\", \"Zoe\"]\nprint(names[0])\nprint(names[-1])\n","sourceChecks":{"0":{"message":"Create the names list instead of only printing the final answers."},"1":{"message":"Use names[0] to print the first name instead of typing Ava directly."},"2":{"message":"Use an index on names to print the last name instead of typing Zoe directly."}}},"try-creating-and-indexing-lists-sketch0":{"title":"Build a list from input","prompt":"Three club names arrive as input. Store them, in the same order, in a list named `clubs`, then print the list. Do not hard-code the club names.","hint":"Build `clubs` from the three input variables in their original order, then print `clubs`.","help":{"concept":"A list can collect values that are already stored in variables.","hint_1":"Assign the three input variables to a list named `clubs` in their original order.","hint_2":"After creating `clubs`, print the variable itself with `print(clubs)`."},"starterCode":"club1 = input()\nclub2 = input()\nclub3 = input()\n\n# Create a list named clubs containing the three inputs.\n# Print the whole list.\n","solutionCode":"club1 = input()\nclub2 = input()\nclub3 = input()\n\nclubs = [club1, club2, club3]\nprint(clubs)\n","sourceChecks":{"0":{"message":"Create a variable named `clubs` as required by the prompt."},"1":{"message":"Print `clubs` itself after creating it."}}},"try-creating-and-indexing-lists-sketch1":{"title":"Read two different positions","prompt":"The list `stations` is already provided. Use list indexing to print the third station first and the first station second, each on its own line. Do not hard-code the station names.","hint":"Use the list positions directly: the third item is `stations[2]` and the first is `stations[0]`.","help":{"concept":"This exercise practices reading values from a list by index rather than typing the known values directly.","hint_1":"Print the third item with `stations[2]`.","hint_2":"Then print the first item with `stations[0]`."},"starterCode":"stations = [\"Oak\", \"Pine\", \"Lake\", \"Hill\"]\n\n# Print the third station.\n# Then print the first station.\n","solutionCode":"stations = [\"Oak\", \"Pine\", \"Lake\", \"Hill\"]\nprint(stations[2])\nprint(stations[0])\n","sourceChecks":{"0":{"message":"Use `stations[2]` to read the third station instead of hard-coding `Lake`."},"1":{"message":"Use `stations[0]` to read the first station instead of hard-coding `Oak`."}}},"try-creating-and-indexing-lists-sketch2":{"title":"Use the last item after building a list","prompt":"Four delivery stops arrive as input. Store them, in their original order, in a list named `stops`. Then print only the final stop by using negative indexing on that list. Do not print the fourth input variable directly.","hint":"Create `stops = [stop1, stop2, stop3, stop4]`, then use `stops[-1]`.","help":{"concept":"Negative indexing reads relative to the end of a list; `-1` means the final item.","hint_1":"Build the `stops` list from all four input variables in their original order.","hint_2":"Print the final item from the list with `print(stops[-1])`, not `print(stop4)`."},"starterCode":"stop1 = input()\nstop2 = input()\nstop3 = input()\nstop4 = input()\n\n# Create a list named stops containing the four inputs.\n# Print the final stop using negative indexing.\n","solutionCode":"stop1 = input()\nstop2 = input()\nstop3 = input()\nstop4 = input()\n\nstops = [stop1, stop2, stop3, stop4]\nprint(stops[-1])\n","sourceChecks":{"0":{"message":"Create `stops = [stop1, stop2, stop3, stop4]` as the prompt requires."},"1":{"message":"Use `stops[-1]` to read the final stop instead of printing `stop4` directly."}}},"sc-last-negative-index":{"title":"Read the last item","prompt":"Which expression gets the last item from `tasks` without needing to know how many items are in the list?","hint":"Python can count backward from the end of a list with negative indexes.","help":{"concept":"Index `-1` always refers to the final item in a non-empty list.","hint_1":"Positive indexes count from the beginning; negative indexes count from the end.","hint_2":"Use `tasks[-1]`."},"options":{"a":"tasks[-1]","b":"tasks[0]","c":"tasks[1]","d":"tasks[\"last\"]"}}},"tryIt":{"try_creating_and_indexing_lists_checkpoint":{"title":"Try it yourself","prompt":"Create the list `[\"Ava\", \"Mia\", \"Zoe\"]`. Print the first name, then print the last name."},"try_creating_and_indexing_lists_sketch0":{"title":"Try it yourself","prompt":"Three club names arrive as input. Store them, in the same order, in a list named `clubs`, then print the list. Do not hard-code the club names."},"try_creating_and_indexing_lists_sketch1":{"title":"Try it yourself","prompt":"The list `stations` is already provided. Use list indexing to print the third station first and the first station second, each on its own line. Do not hard-code the station names."},"try_creating_and_indexing_lists_sketch2":{"title":"Try it yourself","prompt":"Four delivery stops arrive as input. Store them, in their original order, in a list named `stops`. Then print only the final stop by using negative indexing on that list. Do not print the fourth input variable directly."},"allowReveal":true}},"dictionary-basics":{"label":"Dictionary Basics","summary":"Create dictionaries with labeled key-value pairs, retrieve values by key, and check whether a key exists before reading it.","cards":{"sketch0":{"title":"Creating labeled dictionary records"},"sketch1":{"title":"Reading values by key"},"sketch2":{"title":"Checking whether a key exists"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-dict-best-choice":{"title":"Choose labeled data","prompt":"You need to store a person's name, age, and city so each value has a clear label. Which collection is the best fit?","hint":"Choose the collection designed around key-value pairs.","help":{"concept":"A dictionary connects each value to a key such as `\"name\"`, `\"age\"`, or `\"city\"`.","hint_1":"A list or tuple relies mainly on positions.","hint_2":"Choose the collection that lets you look up a value by a label."},"options":{"a":"A dictionary","b":"A tuple","c":"A single string","d":"A number"}},"sc-dict-lookup":{"title":"Read a value by key","prompt":"Given `pet = {\"type\": \"cat\", \"age\": 3}`, which expression gets the value `\"cat\"`?","hint":"Use the dictionary name followed by the exact key in square brackets.","help":{"concept":"Dictionary lookup uses `dictionary[key]`.","hint_1":"The value `\"cat\"` is stored under the key `\"type\"`.","hint_2":"Use `pet[\"type\"]`."},"options":{"a":"pet[0]","b":"pet(\"type\")","c":"pet[\"type\"]","d":"type[\"pet\"]"}},"mc-dict-parts":{"title":"Identify dictionary parts","prompt":"Which statements about this dictionary are correct?\n\n`item = {\"name\": \"pen\", \"price\": 2}`\n\nChoose all correct answers.","hint":"Separate keys from values in each pair.","help":{"concept":"In a dictionary, each entry has a key on the left of the colon and a value on the right.","hint_1":"Check the pair `\"name\": \"pen\"` and the pair `\"price\": 2`.","hint_2":"The strings before colons are keys; the data after colons are values."},"options":{"a":"`\"name\"` is a key","b":"`\"pen\"` is a value","c":"`2` is a value","d":"`\"price\"` is a value"}},"mc-dict-operations":{"title":"Valid dictionary actions","prompt":"Which lines correctly work with a dictionary named `scores = {\"Ava\": 10, \"Ben\": 8}`? Choose all correct answers.","hint":"Think about looking up by key and assigning by key.","help":{"concept":"You can read a dictionary value with `dict[key]` and update or add entries with `dict[key] = value`.","hint_1":"One correct pattern reads a value using a name key in square brackets.","hint_2":"Another correct pattern changes or adds a value by putting a key in square brackets on the left side of `=`."},"options":{"a":"`scores[\"Ava\"]`","b":"`scores[1]`","c":"`scores[\"Ben\"] = 9`","d":"`scores.add(\"Kai\", 7)`"}},"dr-dict-create-order":{"title":"Build a dictionary step by step","prompt":"Put these code pieces in the correct order to create a dictionary and print one value.","hint":"Create the dictionary first, then read from it.","help":{"concept":"Python must create and assign the dictionary before you can look up a value from it.","hint_1":"Start with the variable name and assignment to a dictionary literal.","hint_2":"The print line should come after the dictionary exists, and the lookup uses the key `\"name\"`."},"tokens":{"t1":"person = {","t2":"\"name\": \"Ava\"","t3":"}","t4":"print(person[\"name\"])"}},"dr-dict-update-order":{"title":"Order an update example","prompt":"Arrange these lines to create a dictionary, update a value, and print the updated result.","hint":"The dictionary must exist before the update line.","help":{"concept":"Updating a dictionary uses assignment with a key after the dictionary has already been created.","hint_1":"First create `stock`, then change the value for `\"apples\"`, then print it.","hint_2":"The print line belongs last because it should show the updated value, not the original one."},"tokens":{"t1":"stock = {\"apples\": 5}","t2":"stock[\"apples\"] = 7","t3":"print(stock[\"apples\"])"}},"fb-dict-literal":{"title":"Complete a dictionary literal","prompt":"Choose the missing value to finish the dictionary entry.","hint":"The blank should be the value paired with the key `\"color\"`.","help":{"concept":"A dictionary entry has the form `key: value`, so the missing part here is the value for one key.","hint_1":"The key is already written as `\"color\"`.","hint_2":"Pick the choice that can act as the string value stored for that key."},"template":"paint = {\"color\": [blank1]}","choices":["\"blue\"","color","Lesson notes panel","Color theme picker"]},"fb-dict-key-lookup":{"title":"Complete a key lookup","prompt":"Choose the missing key so the expression gets the age value.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"person = {\"name\": \"Ivy\", \"age\": 12}\nprint(person[[blank1]])","choices":["\"age\"","12","\"Ivy\"","0"]},"ci-make-dictionary":{"title":"Return a simple dictionary","prompt":"Write `make_book(title, pages)` so it returns one dictionary describing the book. The dictionary should use the keys `\"title\"` and `\"pages\"`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_book(title, pages):\n # return a dictionary with keys \"title\" and \"pages\"\n pass","solutionCode":"def make_book(title, pages):\n return {\"title\": title, \"pages\": pages}"},"ci-get-score":{"title":"Look up a value in a dictionary","prompt":"Write `get_score(scores, name)` so it looks up `name` in the `scores` dictionary and returns that score.","hint":"Read the task \"Look up a value in a dictionary\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def get_score(scores, name):\n # return the score for the given name\n pass","solutionCode":"def get_score(scores, name):\n return scores[name]"},"ci-update-dictionary":{"title":"Add or update a dictionary entry","prompt":"Write `set_price(prices, item, amount)` so it updates the `prices` dictionary with the given item and amount, then returns the updated dictionary.","hint":"Read the task \"Add or update a dictionary entry\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def set_price(prices, item, amount):\n # update the dictionary and return it\n pass","solutionCode":"def set_price(prices, item, amount):\n prices[item] = amount\n return prices"},"try-dictionary-basics-checkpoint":{"title":"Create and read a dictionary","prompt":"Create a dictionary for `name` and `score`, then print the score.","hint":"Use the key `\"score\"` to read the value.","help":{"concept":"A dictionary stores values under named keys.","hint_1":"Use the key `\"score\"` to read the value.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"student = {}\n\n# Store name Ava and score 92.\n# Then print the score.\n","solutionCode":"student = {\"name\": \"Ava\", \"score\": 92}\nprint(student[\"score\"])\n","sourceChecks":{"0":{"message":"Create a dictionary variable named student."},"1":{"message":"Use the score key to read the score from student."}}},"try-dictionary-basics-sketch0":{"title":"Build a profile dictionary","prompt":"A name and age arrive as input. Create a dictionary named `profile` with the keys `\"name\"` and `\"age\"`, storing the input values under the matching keys. Then print the whole dictionary. Use a dictionary literal assigned to `profile`; the grader checks that `profile` contains the explicitly requested `\"name\"` and `\"age\"` keys.","hint":"Use a dictionary literal with two `key: value` pairs.","help":{"concept":"A dictionary literal uses `{}` and separates each key from its value with a colon.","hint_1":"Store the variable `name` under the key `\"name\"` and `age` under the key `\"age\"`.","hint_2":"Create `profile = {\"name\": name, \"age\": age}`, then print `profile`."},"starterCode":"name = input()\nage = int(input())\n\n# Create profile with the keys \"name\" and \"age\".\n# Store the input values under those keys.\n# Print the whole dictionary.\n","solutionCode":"name = input()\nage = int(input())\n\nprofile = {\"name\": name, \"age\": age}\nprint(profile)\n","sourceChecks":{"0":{"message":"Create the requested dictionary in a variable named `profile`."},"1":{"message":"Include the explicitly requested `\"name\"` key in the dictionary."},"2":{"message":"Include the explicitly requested `\"age\"` key in the dictionary."}}},"try-dictionary-basics-sketch1":{"title":"Look up a price from input","prompt":"The dictionary `prices` is already defined. Read an item name from input and print the price stored under that key. The test inputs will always be keys that exist in `prices`.","hint":"Use the input variable as the key inside square brackets.","help":{"concept":"A dictionary lookup can use a variable key, not only a literal string.","hint_1":"The selected key is stored in `item`.","hint_2":"Print `prices[item]`."},"starterCode":"prices = {\"notebook\": 4, \"marker\": 2, \"folder\": 3}\nitem = input()\n\n# Print the value stored under the key in item.\n","solutionCode":"prices = {\"notebook\": 4, \"marker\": 2, \"folder\": 3}\nitem = input()\n\nprint(prices[item])\n","sourceChecks":{"0":{"message":"Update profile['age'] to 12 instead of replacing the final dictionary."}}},"try-dictionary-basics-sketch2":{"title":"Check whether a setting exists","prompt":"The dictionary `settings` contains several configuration keys. Read a key from input. If that key exists in `settings`, print `found`; otherwise print `missing`.","hint":"Use `key in settings` as the condition.","help":{"concept":"The `in` operator checks whether a dictionary contains a key without trying to read its value.","hint_1":"Use `if key in settings:` for the found case.","hint_2":"Print `found` in the `if` block and `missing` in the `else` block."},"starterCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\n# Print \"found\" if key exists in settings.\n# Otherwise print \"missing\".\n","solutionCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\nif key in settings:\n print(\"found\")\nelse:\n print(\"missing\")\n","sourceChecks":{"0":{"message":"Create a dictionary variable named scores."},"1":{"message":"Use Ava as a key in scores."},"2":{"message":"Use Mia as a key in scores."}}},"sc-key-value-role":{"title":"Identify a key and its value","prompt":"In `book = {\"title\": \"Kindred\", \"pages\": 264}`, what is `\"pages\"`?","hint":"Look at which side of the colon the item appears on.","help":{"concept":"In a dictionary entry, the key appears before the colon and its value appears after the colon.","hint_1":"The pair here is `\"pages\": 264`.","hint_2":"`\"pages\"` is the key; `264` is the value."},"options":{"a":"A key","b":"A value","c":"A list index","d":"A method"}},"sc-key-membership":{"title":"Check for a key safely","prompt":"Given `profile = {\"name\": \"Ava\", \"age\": 12}`, which expression checks whether the key `\"city\"` exists in the dictionary?","hint":"Use the membership operator with the key on the left and the dictionary on the right.","help":{"concept":"For dictionaries, `key in dictionary` checks whether that key exists.","hint_1":"You are checking for a key, not reading its value yet.","hint_2":"Use `\"city\" in profile`."},"options":{"a":"\"city\" in profile","b":"profile[\"city\"]","c":"\"city\" == profile","d":"profile.in(\"city\")"}}},"tryIt":{"try_dictionary_basics_checkpoint":{"title":"Try it yourself","prompt":"Create a dictionary for `name` and `score`, then print the score."},"try_dictionary_basics_sketch0":{"title":"Try it yourself","prompt":"A name and age arrive as input. Create a dictionary named `profile` with the keys `\"name\"` and `\"age\"`, storing the input values under the matching keys. Then print the whole dictionary. Use a dictionary literal assigned to `profile`; the grader checks that `profile` contains the explicitly requested `\"name\"` and `\"age\"` keys."},"try_dictionary_basics_sketch1":{"title":"Try it yourself","prompt":"Read a valid item key from input and print the matching value from `prices`."},"try_dictionary_basics_sketch2":{"title":"Try it yourself","prompt":"Read a key from input and print whether that key exists in `settings`."},"allowReveal":true}},"list-methods-and-mutation":{"label":"List Methods and Mutation","summary":"Change existing list items, add and remove values, capture removed items with pop(), and sort a list in place.","cards":{"sketch0":{"title":"Replacing an item by index"},"sketch1":{"title":"Adding an item with append()"},"sketch2":{"title":"Removing a matching value"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Removing by position with pop()"},"sketch4":{"title":"Sorting the same list"}},"quiz":{"sc-1":{"title":"Which method adds to the end?","prompt":"Which list method adds one new item to the end of a list?","hint":"Use execution order as evidence instead of choosing by familiar wording.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"append()","b":"remove()","c":"pop()","d":"sort()"}},"sc-2":{"title":"What does pop return?","prompt":"In Python, what does `items.pop(1)` return?","hint":"`pop()` both changes the list and gives you something back.","help":{"concept":"`pop(index)` removes the item at the given index and returns that removed item.","hint_1":"Index `1` means the second item in the list.","hint_2":"The return value is not the shortened list itself; it is the element that was taken out."},"options":{"a":"The item that was removed at index 1","b":"A copy of the whole list","c":"The length of the list after removal","d":"Nothing at all"}},"mc-1":{"title":"Methods that mutate a list","prompt":"Which of these operations change the original list? Choose all that apply.","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"append(5)","b":"remove(5)","c":"sort()","d":"len(my_list)"}},"mc-2":{"title":"Valid list method uses","prompt":"Which lines are valid ways to use common list methods on `numbers = [3, 1, 2]`? Choose all that apply.","hint":"Check whether each method name matches the kind of argument it expects.","help":{"concept":"Different list methods expect different inputs: `append` takes a value, `remove` takes a value, and `pop` usually takes an index.","hint_1":"Ask whether the method is removing by value or by position.","hint_2":"One choice mixes up `remove` with index behavior, and one choice uses `sort` with an argument it does not need here."},"options":{"a":"numbers.append(4)","b":"numbers.remove(1)","c":"numbers.pop(0)","d":"numbers.sort(2)"}},"dr-1":{"title":"Append then inspect","prompt":"Put these steps in the correct order to add `7` to a list and display the updated list.","hint":"First create the list, then change it, then print it.","help":{"concept":"A short list program usually follows a sequence: create data, mutate data, then inspect the result with `print()`.","hint_1":"You cannot append to a list before the list exists.","hint_2":"Printing should happen after the append if you want to see the changed list."},"tokens":{"t1":"numbers = [1, 2]","t2":"numbers.append(7)","t3":"print(numbers)"}},"dr-2":{"title":"Remove, pop, then print","prompt":"Arrange the lines to produce a program that removes `\"b\"`, then pops the last remaining item into `taken`, then prints `taken`.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"letters = [\"a\", \"b\", \"c\"]","t2":"letters.remove(\"b\")","t3":"taken = letters.pop()","t4":"print(taken)"}},"fb-1":{"title":"Complete an append call","prompt":"Choose the value that makes `numbers.append(...)` add `10` to the list.","hint":"`append()` needs the item you want to add inside the parentheses.","help":{"concept":"To add one item to the end of a list, place that item as the argument to `append()`.","hint_1":"The blank is the new value being added, not the list name or method name.","hint_2":"Pick the choice that would make the list gain the number ten."},"template":"numbers = [1, 2]\nnumbers.append([blank1])","choices":["numbers","append","10","pop"]},"fb-2":{"title":"Complete a sort statement","prompt":"Choose the method name that sorts `scores` in place.","hint":"This method puts list items in order and changes the list itself.","help":{"concept":"Choose the list method that rearranges the existing list into order instead of returning a separate sorted copy.","hint_1":"The blank should be a method that works directly on a list variable.","hint_2":"It is not a method for adding or removing items."},"template":"scores = [4, 1, 3]\nscores.[blank1]()","choices":["append","remove","sort","pop"]},"ci-1":{"title":"Add an item and print the list","prompt":"A pencil case already has `pen` and `pencil`. Read one more item from input, add it to `items`, and print the updated list.\n\nFor example, if the input is `eraser`, your program should print:\n`['pen', 'pencil', 'eraser']`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"item = input()\nitems = [\"pen\", \"pencil\"]\n\n# Add the input item to the list.\n# Then print the updated list.","solutionCode":"item = input()\nitems = [\"pen\", \"pencil\"]\nitems.append(item)\nprint(items)","sourceChecks":{"0":{"message":"Use items.append(item) so the list is really mutated."}}},"ci-2":{"title":"Remove a value and show the result","prompt":"The list `colors` starts as `['red', 'blue', 'green']`. Read one color from input, remove that value from the list, and print the updated list.\n\nFor example, if the input is `blue`, your program should print:\n`['red', 'green']`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"color = input()\ncolors = ['red', 'blue', 'green']\n\n# Remove the input color from the list.\n# Then print the updated list.","solutionCode":"color = input()\ncolors = ['red', 'blue', 'green']\ncolors.remove(color)\nprint(colors)","sourceChecks":{"0":{"message":"Use colors.remove(color) so the list is really mutated."}}},"ci-3":{"title":"Sort numbers from input","prompt":"Three quiz scores arrive out of order. Put the input numbers into `numbers`, sort the list from smallest to largest, and print the sorted list.\n\nFor example, if the inputs are `9`, `2`, and `5`, your program should print:\n`[2, 5, 9]`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\n\nnumbers = [a, b, c]\n\n# Sort the list.\n# Then print the sorted list.","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\n\nnumbers = [a, b, c]\nnumbers.sort()\nprint(numbers)","sourceChecks":{"0":{"message":"Use numbers.sort() so the list is really sorted in place."}}},"try-list-methods-and-mutation-checkpoint":{"title":"Append 10 to a list","prompt":"Start with `numbers = [3, 1, 2]`. Add `10` to the end of the list, then print the updated list.","hint":"Use `append()` to add one item to the end.","help":{"concept":"`append(value)` mutates the original list by adding one item to the end.","hint_1":"Use `append()` to add one item to the end.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"numbers = [3, 1, 2]\n\n# Add 10 to the end of the list.\n# Then print the updated list.\n","solutionCode":"numbers = [3, 1, 2]\nnumbers.append(10)\nprint(numbers)\n","sourceChecks":{"0":{"message":"Use numbers.append(10) so the list is really changed."}}},"try-list-methods-and-mutation-sketch0":{"title":"Correct one score","prompt":"A score was entered incorrectly. Read the corrected score from input. Use indexed assignment on the existing `scores` list to replace its last item with that value, then print the updated list.","hint":"Use list indexing on the left side of an assignment to change the final item of `scores`. Any valid index expression that selects the last item is acceptable.","help":{"concept":"Indexed assignment changes an existing list item in place. The index expression inside the brackets can be written in different valid ways.","hint_1":"Write an assignment to `scores[...]` where the expression inside the brackets selects the final item.","hint_2":"Assign `corrected_score` to that indexed position, then print `scores` itself."},"starterCode":"corrected_score = int(input())\nscores = [12, 15, 18]\n\n# Replace the last score with corrected_score.\n# Then print the updated list.\n","solutionCode":"corrected_score = int(input())\nscores = [12, 15, 18]\n\nscores[2] = corrected_score\nprint(scores)\n","sourceChecks":{"0":{"message":"Use indexed assignment on the existing `scores` list: assign `corrected_score` to a `scores[...]` position that selects the last item."},"1":{"message":"Print the updated `scores` list itself after changing it."}}},"try-list-methods-and-mutation-sketch1":{"title":"Add a new attendee","prompt":"A new attendee name arrives as input. Add that name to the end of `attendees` with `append()`, then print the updated list.","hint":"Pass the input variable to `attendees.append(...)`.","help":{"concept":"`append(value)` adds exactly one new item to the end of the existing list.","hint_1":"Do not type the incoming name directly into the list; use the value stored in `new_attendee`.","hint_2":"Call `attendees.append(new_attendee)`, then print `attendees`."},"starterCode":"new_attendee = input()\nattendees = [\"Ava\", \"Noah\"]\n\n# Add new_attendee to the end of attendees.\n# Then print the updated list.\n","solutionCode":"new_attendee = input()\nattendees = [\"Ava\", \"Noah\"]\n\nattendees.append(new_attendee)\nprint(attendees)\n","sourceChecks":{"0":{"message":"Use `append()` because that method is explicitly required by the prompt."},"1":{"message":"Print the updated `attendees` list itself after using `append()`."}}},"try-list-methods-and-mutation-sketch2":{"title":"Remove a canceled workshop","prompt":"One workshop has been canceled. Read its name from input, remove that matching value from `workshops` with `remove()`, then print the remaining workshops.","hint":"`remove(value)` searches for a matching value and deletes the first match.","help":{"concept":"`remove(value)` changes the list by deleting the first item equal to that value.","hint_1":"Use the input stored in `canceled` rather than hard-coding one workshop name.","hint_2":"Call `workshops.remove(canceled)`, then print `workshops`."},"starterCode":"canceled = input()\nworkshops = [\"Python\", \"Excel\", \"SQL\", \"Git\"]\n\n# Remove the workshop whose name is stored in canceled.\n# Then print the updated list.\n","solutionCode":"canceled = input()\nworkshops = [\"Python\", \"Excel\", \"SQL\", \"Git\"]\n\nworkshops.remove(canceled)\nprint(workshops)\n","sourceChecks":{"0":{"message":"Use `remove()` because that method is explicitly required by the prompt."},"1":{"message":"Print the mutated `workshops` list itself after removing the canceled workshop."}}},"sc-index-assignment":{"title":"Replace one list item","prompt":"The list is `tasks = [\"email\", \"meeting\", \"backup\"]`. Which line replaces the second item with `\"study\"`?","hint":"Reading an item uses an index. Replacing an item uses that same indexed position on the left side of `=`.","help":{"concept":"Assigning to `list[index]` changes the item stored at that position.","hint_1":"The second item is at index `1` because Python starts counting at 0.","hint_2":"Use `tasks[1] = \"study\"`."},"options":{"a":"tasks[1] = \"study\"","b":"tasks[0] = \"study\"","c":"tasks.append(\"study\")","d":"tasks(1) = \"study\""}},"mc-mutates-original":{"title":"Operations that mutate a list","prompt":"Which operations change the existing list itself? Assume `items` is already a list. Choose all that apply.","hint":"Think about whether the list's stored items are different after the operation runs.","help":{"concept":"Index assignment and list methods such as `append`, `remove`, `pop`, and `sort` mutate the existing list.","hint_1":"`len(items)` reads information but does not change any item.","hint_2":"Choose the operations that replace, add, remove, or reorder list items."},"options":{"a":"items[0] = \"new\"","b":"items.append(\"new\")","c":"items.pop()","d":"len(items)"}},"sc-remove-vs-pop":{"title":"Remove by position and keep the value","prompt":"You need to remove the item at index `1` from `colors` and store the removed value in `removed`. Which line does both?","hint":"`remove()` looks for a matching value. `pop()` removes by position and returns what it removed.","help":{"concept":"`pop(index)` removes the item at that index and returns the removed value.","hint_1":"The task gives a position, not a value to search for.","hint_2":"Assign the result of `colors.pop(1)` to `removed`."},"options":{"a":"removed = colors.pop(1)","b":"removed = colors.remove(1)","c":"colors.remove(removed)","d":"removed = colors[1]"}},"sc-sort-return":{"title":"What sort() returns","prompt":"What is printed by this code?\n\n`scores = [8, 3, 5]`\n`result = scores.sort()`\n`print(result)`","hint":"`sort()` changes `scores` in place; it does not return the sorted list.","help":{"concept":"`list.sort()` mutates the list and returns `None`.","hint_1":"After sorting, `scores` is ordered, but `result` receives the method's return value.","hint_2":"That return value is `None`."},"options":{"a":"None","b":"[3, 5, 8]","c":"8","d":"Nothing is printed because the program crashes"}},"try-list-methods-and-mutation-sketch3":{"title":"Take the second ticket","prompt":" Use `pop()` with the index of the second item, store the removed ticket in `next_ticket`, then print the removed value. Do not hard-code the ticket.","hint":"`pop(1)` removes the item at index 1 and returns that removed item.","help":{"concept":"`pop(index)` is useful when you know the position and also need the removed value.","hint_1":"Assign the result of `tickets.pop(1)` to `next_ticket`.","hint_2":"Print `next_ticket` first, then print `tickets`."},"starterCode":"tickets = [\"T-104\", \"T-105\", \"T-106\", \"T-107\"]\n\n# Remove the second ticket with pop(1) and store it in next_ticket.\n# Print next_ticket.\n# Then print the remaining tickets list.\n","solutionCode":"tickets = [\"T-104\", \"T-105\", \"T-106\", \"T-107\"]\n\nnext_ticket = tickets.pop(1)\nprint(next_ticket)\nprint(tickets)\n","sourceChecks":{"0":{"message":"Use `pop()` because that method is explicitly required by the prompt."},"1":{"message":"Print `next_ticket` itself instead of typing the known removed ticket."},"2":{"message":"Print the remaining `tickets` list itself after `pop()` changes it."}}},"try-list-methods-and-mutation-sketch4":{"title":"Sort three incoming times","prompt":"Three completion times arrive as integers. Store them in a list named `times`, sort the same list from smallest to largest with `sort()`, then print the sorted list.","hint":"Create `times` from the three input variables before calling `times.sort()`.","help":{"concept":"`sort()` rearranges the existing list in ascending order.","hint_1":"Build one list from `first`, `second`, and `third` in that order.","hint_2":"Call `times.sort()` before printing `times`."},"starterCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\n# Create a list named times from the three inputs.\n# Sort times from smallest to largest.\n# Print the sorted list.\n","solutionCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\ntimes = [first, second, third]\ntimes.sort()\nprint(times)\n","sourceChecks":{"0":{"message":"Use `sort()` because that method is explicitly required by the prompt."},"1":{"message":"Print the sorted `times` list itself after sorting it in place."}}}},"tryIt":{"try_list_methods_and_mutation_checkpoint":{"title":"Try it yourself","prompt":"Start with `numbers = [3, 1, 2]`. Add `10` to the end of the list, then print the updated list."},"try_list_methods_and_mutation_sketch0":{"title":"Try it yourself","prompt":"A score was entered incorrectly. Read the corrected score from input, replace the last item in `scores` with that value, then print the updated list."},"try_list_methods_and_mutation_sketch1":{"title":"Try it yourself","prompt":"A new attendee name arrives as input. Add that name to the end of `attendees` with `append()`, then print the updated list."},"try_list_methods_and_mutation_sketch2":{"title":"Try it yourself","prompt":"One workshop has been canceled. Read its name from input, remove that matching value from `workshops` with `remove()`, then print the remaining workshops."},"allowReveal":true,"try_list_methods_and_mutation_sketch3":{"title":"Try it yourself","prompt":"The second ticket in `tickets` is ready to be processed. Remove that item with `pop(1)`, store the removed value in `next_ticket`, then print `next_ticket` followed by the remaining list. Use `pop()` with the index of the second item, store the removed ticket in `next_ticket`, then print the removed value. Do not hard-code the ticket."},"try_list_methods_and_mutation_sketch4":{"title":"Try it yourself","prompt":"Three completion times arrive as integers. Store them in a list named `times`, sort the same list from smallest to largest with `sort()`, then print the sorted list."}}},"looping-through-lists":{"label":"Looping Through Lists","summary":"Loop through list items to print values, accumulate totals, build transformed lists, and keep only values that meet a condition.","cards":{"sketch0":{"title":"Processing each item in a list"},"sketch1":{"title":"Building a running total"},"sketch2":{"title":"Building a transformed list"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Filtering items while you loop"}},"quiz":{"sc-loop-item-name":{"title":"What the loop variable holds","prompt":"In this loop, what does `fruit` hold during each iteration?\n\n```python\nfruits = [\"apple\", \"banana\", \"pear\"]\nfor fruit in fruits:\n print(fruit)\n```","hint":"Look at the name immediately after `for`.","help":{"concept":"The loop variable holds one current item from the list at a time.","hint_1":"The list itself is named `fruits`; the singular name `fruit` changes on each pass.","hint_2":"`fruit` is `\"apple\"`, then `\"banana\"`, then `\"pear\"`."},"options":{"a":"The entire fruits list","b":"One current item from fruits","c":"The numeric index of the current item","d":"The number of items in fruits"}},"sc-empty-list-start":{"title":"Start a result list","prompt":"You want to collect new values while looping. Which line correctly creates an empty list named `result`?","hint":"An empty list literal uses square brackets with nothing between them.","help":{"concept":"A common list-building pattern starts with an empty list and appends values during the loop.","hint_1":"Parentheses create a tuple, while square brackets create a list.","hint_2":"Use `result = []`."},"options":{"a":"result = []","b":"result = ()","c":"result = \"\"","d":"print(result)"}},"mc-loop-uses":{"title":"What loops through a list can do","prompt":"Which actions are common reasons to loop through a list? Choose all that apply.","hint":"Think about tasks you repeat once for each item.","help":{"concept":"List loops are used to process each item, such as printing values, checking conditions, or building a new list from transformed items.","hint_1":"A loop is useful when the same action should happen for every item in the list.","hint_2":"Look for choices about repeated processing of items, not choices about changing Python syntax itself."},"options":{"a":"Print each item","b":"Build a new list from changed items","c":"Check whether items meet a condition","d":"Rename Python keywords"}},"mc-good-loop-names":{"title":"Choose clear loop variable names","prompt":"For the list `scores = [88, 91, 76]`, which loop variable names are clear and appropriate? Choose all that apply.","hint":"Trace the code before choosing the option that matches its actual behavior.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"score","b":"item","c":"scores","d":"score_value"}},"dr-build-derived-list":{"title":"Order the steps to build a derived list","prompt":"Arrange these steps in the correct order for building a new list from an existing list.","hint":"Start by creating the new list before the loop begins.","help":{"concept":"To build a derived list, first create an empty list, then loop through the original list, compute each new value, and append it.","hint_1":"The empty list setup happens before any items are processed.","hint_2":"Inside the loop, you first get the current item, then create the changed value, then add it to the result list."},"tokens":{"t1":"Create an empty result list","t2":"Start a loop over the original list","t3":"Compute the changed value for the current item","t4":"Append the changed value to the result list"}},"dr-read-loop-header":{"title":"Read the loop in order","prompt":"Put these parts of the loop statement in the correct order to make a valid Python loop header.","hint":"Focus on the logical order of the parts.","help":{"concept":"Arrange the pieces according to the structure of the statement.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Put the pieces in the order that makes the statement valid."},"tokens":{"t1":"for","t2":"color","t3":"in","t4":"colors","t5":":"}},"fb-append-call":{"title":"Complete the append line","prompt":"Fill in the missing method name to add each changed item to the result list.","hint":"Use the list method that adds one item to the end.","help":{"concept":"Choose the list method that adds one new value to the end during each iteration.","hint_1":"The method is called on the list you are building, like `result.method(value)`.","hint_2":"It is the common list method used in beginner loops to collect new values."},"template":"result.[blank1](number * 2)","choices":["append","add","insert","print"]},"fb-loop-keyword":{"title":"Complete the loop header","prompt":"Fill in the missing keyword to start a loop over a list.","hint":"Use execution order as evidence instead of choosing by familiar wording.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"template":"[blank1] item in items:","choices":["for","if","while","def"]},"ci-print-each-item":{"title":"Print each item in a list","prompt":"A shelter roll call stores three animal names in `animals`. Loop through `animals` and print each name on its own line.\n\nFor example, if the inputs are `cat`, `dog`, and `fox`, your program should print:\n`cat`\n`dog`\n`fox`.","hint":"Build the list from the three input values before the loop starts.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"first = input()\nsecond = input()\nthird = input()\n\nanimals = [first, second, third]\n\n# Loop through animals and print each one.\n","solutionCode":"first = input()\nsecond = input()\nthird = input()\n\nanimals = [first, second, third]\n\nfor animal in animals:\n print(animal)\n","sourceChecks":{"0":{"message":"Use a for loop over animals instead of printing each variable manually."}}},"ci-double-list-function":{"title":"Return a doubled list","prompt":"Write `double_numbers(numbers)` so it builds a new list containing each number doubled, then returns that new list.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def double_numbers(numbers):\n # build and return a new list\n pass","solutionCode":"def double_numbers(numbers):\n result = []\n for number in numbers:\n result.append(number * 2)\n return result"},"ci-count-long-words":{"title":"Count words longer than 4 letters","prompt":"Write `count_long_words(words)` so it returns how many words in the list are longer than 4 letters.","hint":"Read the task \"Count words longer than 4 letters\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def count_long_words(words):\n # return the number of words longer than 4 letters\n pass","solutionCode":"def count_long_words(words):\n count = 0\n for word in words:\n if len(word) > 4:\n count += 1\n return count"},"try-looping-through-lists-checkpoint":{"title":"Loop through names","prompt":"Loop through `names = [\"Ava\", \"Mia\", \"Zoe\"]` and print each name on its own line.","hint":"Use a `for` loop.","help":{"concept":"A `for` loop can visit each value in a list.","hint_1":"Use a `for` loop.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"names = [\"Ava\", \"Mia\", \"Zoe\"]\n\n# Print each name on its own line.\n","solutionCode":"names = [\"Ava\", \"Mia\", \"Zoe\"]\nfor name in names:\n print(name)\n","sourceChecks":{"0":{"message":"Use a for loop over names instead of printing each name manually."}}},"try-looping-through-lists-sketch0":{"title":"Print room labels from input","prompt":"Three room names arrive as input. Store them in a list named `rooms`. Loop through `rooms` and print each room as `Room: <name>` on its own line.","hint":"Build `rooms` first, then use one `for` loop so the same print statement runs for every room.","help":{"concept":"A loop lets one block of code process every item in a list.","hint_1":"Use a singular loop variable such as `room` for one current value from `rooms`.","hint_2":"Inside the loop, print `\"Room:\"` and the current `room`."},"starterCode":"first = input()\nsecond = input()\nthird = input()\n\n# Create a list named rooms from the three inputs.\n# Loop through rooms.\n# Print each item as: Room: <name>\n","solutionCode":"first = input()\nsecond = input()\nthird = input()\n\nrooms = [first, second, third]\nfor room in rooms:\n print(\"Room:\", room)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `rooms` as the prompt requests."}}},"try-looping-through-lists-sketch1":{"title":"Total four delivery times","prompt":"Four delivery times arrive as integers. Store them in a list named `minutes`. Start `total` at 0, loop through `minutes`, add each value into `total`, then print the final total.","hint":"Initialize `total = 0` before the loop, then update it once for each current value.","help":{"concept":"An accumulator stores a result that grows as the loop processes each item.","hint_1":"The loop variable can be named `minute` because it represents one value from `minutes`.","hint_2":"Inside the loop, use `total += minute`. Print `total` after the loop."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\n# Create a list named minutes from the four inputs.\n# Start total at 0.\n# Add each minute value into total with a loop.\n# Print the final total.\n","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\nminutes = [a, b, c, d]\ntotal = 0\nfor minute in minutes:\n total += minute\nprint(total)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `minutes` as the prompt requests."},"1":{"message":"Add each score into total inside the loop."}}},"try-looping-through-lists-sketch2":{"title":"Build adjusted values","prompt":"Three integer readings arrive as input. Store them in `readings`. Create an empty list named `adjusted`, then loop through `readings` and append each value plus 5. Print the completed `adjusted` list.","hint":"The result list starts empty and receives one transformed value during each loop iteration.","help":{"concept":"A transformation loop creates one new value for every item in the original list.","hint_1":"Create `adjusted = []` before the loop.","hint_2":"Inside the loop, use `adjusted.append(reading + 5)`."},"starterCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\n# Create readings from the three inputs.\n# Create an empty list named adjusted.\n# Append each reading plus 5 to adjusted.\n# Print adjusted.\n","solutionCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\nreadings = [first, second, third]\nadjusted = []\nfor reading in readings:\n adjusted.append(reading + 5)\nprint(adjusted)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `readings` as the prompt requests."},"1":{"message":"Use doubled.append(...) to build the list."}}},"sc-running-total":{"title":"Update a running total","prompt":"Which line belongs inside this loop to add every score into `total`?\n\n```python\nscores = [4, 7, 3]\ntotal = 0\nfor score in scores:\n # missing line\n```","hint":"The current item is stored in `score`, and the accumulated value is stored in `total`.","help":{"concept":"A running total repeatedly adds the current item to an accumulator variable.","hint_1":"The new total should include the old `total` plus the current `score`.","hint_2":"Use `total += score`."},"options":{"a":"total += score","b":"score += total","c":"total = 0","d":"scores.append(total)"}},"sc-filter-append":{"title":"Append only matching items","prompt":"You want `passing` to contain only scores that are at least 60. Where should `passing.append(score)` run?","hint":"Only matching scores should be appended.","help":{"concept":"Filtering combines a loop with a condition so only selected items are added to the result list.","hint_1":"The append should not run for scores below 60.","hint_2":"Put the append inside `if score >= 60:`."},"options":{"a":"Inside `if score >= 60:`","b":"Before the `for` loop","c":"After the loop finishes","d":"Inside `if score < 60:`"}},"try-looping-through-lists-sketch3":{"title":"Keep only high scores","prompt":"Four scores arrive as integers. Store them in `scores`. Create an empty list named `high_scores`, then loop through `scores` and append only values that are 80 or higher. Print the completed `high_scores` list.","hint":"The append should run only when the current score passes the condition.","help":{"concept":"Filtering keeps some list items and skips others based on a condition.","hint_1":"Inside the loop, check `if score >= 80:`.","hint_2":"Indent `high_scores.append(score)` inside that `if` block."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\n# Create scores from the four inputs.\n# Create an empty list named high_scores.\n# Keep only scores that are 80 or higher.\n# Print high_scores.\n","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\nscores = [a, b, c, d]\nhigh_scores = []\nfor score in scores:\n if score >= 80:\n high_scores.append(score)\nprint(high_scores)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `scores` as the prompt requests."}}}},"tryIt":{"try_looping_through_lists_checkpoint":{"title":"Try it yourself","prompt":"Loop through `names = [\"Ava\", \"Mia\", \"Zoe\"]` and print each name on its own line."},"try_looping_through_lists_sketch0":{"title":"Try it yourself","prompt":"Three room names arrive as input. Store them in a list named `rooms`. Loop through `rooms` and print each room as `Room: <name>` on its own line."},"try_looping_through_lists_sketch1":{"title":"Try it yourself","prompt":"Four delivery times arrive as integers. Store them in a list named `minutes`. Use a running total in a loop, then print the final total."},"try_looping_through_lists_sketch2":{"title":"Try it yourself","prompt":"Three integer readings arrive as input. Build a new `adjusted` list containing each reading plus 5, then print the completed list."},"allowReveal":true,"try_looping_through_lists_sketch3":{"title":"Try it yourself","prompt":"Four scores arrive as input. Build `high_scores` containing only scores that are 80 or higher, then print the completed list."}}},"module-5-workshop-schedule-project":{"label":"Module 5 Workshop Schedule Project","summary":"Build a community workshop schedule from tuple records, preserve their order in a list, create a direct room lookup, and group workshop names inside room lists.","cards":{"sketch0":{"title":"Plan the schedule data"},"project":{"title":"Workshop Schedule Builder"}},"projectSteps":{"exercise1":{"title":"Expand the ordered schedule"},"exercise2":{"title":"Build a room lookup"},"exercise3":{"title":"Group workshops by room"}},"quiz":{"try-workshop-schedule-sketch0":{"title":"Preview the schedule pattern","prompt":"Create `schedule` as a list containing one tuple: `(\"Python Basics\", \"Room A\")`. Loop through `schedule`, unpack each tuple into `name` and `room`, and print each workshop as `name — room`.","hint":"The outer structure is a list; each item is a two-field tuple that can be unpacked in the loop header.","help":{"concept":"The project will use a list to preserve workshop order and a tuple for each fixed `(name, room)` record.","hint_1":"Start with `schedule = [(\"Python Basics\", \"Room A\")]`.","hint_2":"Use `for name, room in schedule:` and print the two unpacked values."},"starterCode":"# Create schedule as a list containing one (name, room) tuple.\n# Loop through schedule, unpack each tuple, and print: name — room\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","sourceChecks":{"0":{"message":"Use a `for` loop over `schedule` as the prompt requests."}}},"exercise1":{"title":"Expand the ordered schedule","prompt":"Step 1 of 3 starts from the working one-session preview. Read two more workshop names and rooms from input in this order: `name2`, `room2`, `name3`, `room3`. Append `(name2, room2)` and `(name3, room3)` to `schedule`. Keep the existing loop so the complete schedule prints in order as `name — room`, one workshop per line. For this step, add the second and third workshop records to `schedule` using `append()`. Then process the completed schedule with a `for` loop over `schedule`.","hint":"Read the four input values first, append two tuple records, then let the existing loop print the ordered list.","help":{"concept":"A list preserves workshop order, and `.append()` can add new fixed tuple records without replacing the existing schedule.","hint_1":"Use `schedule.append((name2, room2))` and then append the third record.","hint_2":"Do not hard-code the two new workshop names or rooms; the tests provide different input values."},"starterCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","sourceChecks":{"0":{"message":"Append the second workshop with `schedule.append((name2, room2))`."},"1":{"message":"Append the third workshop with `schedule.append((name3, room3))`."},"2":{"message":"Keep a `for` loop over `schedule` so the finished schedule is processed in order."}}},"exercise2":{"title":"Build a room lookup","prompt":"Step 2 of 3 starts from your completed ordered schedule. Keep that behavior. Create an empty dictionary named `room_lookup`, loop through `schedule`, and store each workshop name as a key in `room_lookup` with its room as the corresponding value. Then read one workshop name into `requested` and look up that workshop in `room_lookup` and print the stored room.","hint":"Build the dictionary from the tuple records instead of writing the room mappings by hand.","help":{"concept":"The ordered list remains useful for the board, while a dictionary gives direct lookup by workshop name.","hint_1":"Initialize `room_lookup = {}` and fill it inside a loop over `schedule`.","hint_2":"After the dictionary is built, read `requested` and print `room_lookup[requested]`."},"starterCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n\nroom_lookup = {}\nfor name, room in schedule:\n room_lookup[name] = room\n\nrequested = input()\nprint(room_lookup[requested])\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"exercise3":{"title":"Group workshops by room","prompt":"Step 3 of 3 starts from the schedule board and direct lookup. Keep both. Build a nested dictionary named `room_sessions` where each room key stores a list of workshop names held in that room. Loop through `schedule`. If the room already exists in `room_sessions`, append the current workshop name to its list; otherwise create a new one-item list. Finally read `room_query` and print `room_sessions[room_query]`.","hint":"Use dictionary membership to decide whether to append to an existing room list or create that list.","help":{"concept":"A dictionary whose values are lists can group several workshop names under the same room key.","hint_1":"Inside the loop, use `if room in room_sessions:` and append `name` to the existing list.","hint_2":"In the `else` branch, create the first list with `room_sessions[room] = [name]`."},"starterCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n\nroom_lookup = {}\nfor name, room in schedule:\n room_lookup[name] = room\n\nrequested = input()\nprint(room_lookup[requested])\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n\nroom_lookup = {}\nfor name, room in schedule:\n room_lookup[name] = room\n\nrequested = input()\nprint(room_lookup[requested])\n\nroom_sessions = {}\nfor name, room in schedule:\n if room in room_sessions:\n room_sessions[room].append(name)\n else:\n room_sessions[room] = [name]\n\nroom_query = input()\nprint(room_sessions[room_query])\n","sourceChecks":{"0":{"message":"Use a `for` loop over `schedule` to process each workshop record, as the prompt requests."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}}},"tryIt":{"try_workshop_schedule_sketch0":{"title":"Try it yourself","prompt":"Create a one-workshop schedule as a list of tuples, then loop through it and unpack the record."},"allowReveal":true}},"nested-data-structures":{"label":"Nested Data Structures","summary":"Work with lists of dictionaries, dictionaries inside dictionaries, and lists stored inside dictionaries by accessing, updating, and looping through one layer at a time.","cards":{"sketch0":{"title":"Reading from a list of dictionaries"},"sketch1":{"title":"Reading and updating a nested dictionary"},"sketch2":{"title":"Changing a list stored inside a dictionary"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Looping through a list of records"}},"quiz":{"sc-1":{"title":"Choose the best structure","prompt":"You want to store several products, and each product has a name and a price. Which structure is the best fit?","hint":"Use execution order as evidence instead of choosing by familiar wording.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"A single string with all product names","b":"A list of dictionaries","c":"One number for each product","d":"A tuple with only one product"}},"sc-2":{"title":"Read a nested value","prompt":"Given `item = {\"name\": \"Pen\", \"info\": {\"price\": 2, \"stock\": 9}}`, which expression gets the value `9`?","hint":"First access the inner dictionary stored at `\"info\"`.","help":{"concept":"To read a nested dictionary value, access the outer key first, then the inner key.","hint_1":"`\"stock\"` is not at the top level of `item`; it is inside `item[\"info\"]`.","hint_2":"The correct expression uses two bracket lookups in order: outer key, then inner key."},"options":{"a":"item[\"stock\"]","b":"item[\"info\"][\"stock\"]","c":"item[\"name\"][\"stock\"]","d":"item[0][\"stock\"]"}},"mc-1":{"title":"Valid nested structures","prompt":"Which of these are examples of nested data structures in Python? Choose all that apply.","hint":"A structure is nested when one collection is stored inside another.","help":{"concept":"Nested data structures contain collections inside collections, such as a list inside a dictionary or dictionaries inside a list.","hint_1":"Check whether each option includes one container placed inside another container.","hint_2":"A plain number or plain string alone is not nested; combinations like list-of-dicts or dict-with-list are."},"options":{"a":"[{\"name\": \"Ava\"}, {\"name\": \"Ben\"}]","b":"{\"scores\": [10, 20, 30]}","c":"42","d":"\"hello\""}},"mc-2":{"title":"Useful access patterns","prompt":"Suppose `players = [{\"name\": \"Mia\", \"points\": 7}, {\"name\": \"Leo\", \"points\": 5}]`. Which expressions are valid ways to read data from this structure? Choose all that apply.","hint":"Start by deciding whether you need a list index first or a dictionary key first.","help":{"concept":"For a list of dictionaries, you use a numeric index to choose one dictionary, then a string key to read a value from that dictionary.","hint_1":"`players` is a list first, so expressions that begin with a string key on `players` are not correct.","hint_2":"Look for expressions that use `[0]` or `[1]` before `['name']` or `['points']`."},"options":{"a":"players[0][\"name\"]","b":"players[1][\"points\"]","c":"players[\"name\"]","d":"players[0][0]"}},"dr-1":{"title":"Access a city name","prompt":"Put these tokens in order to build the expression that gets `\"Paris\"` from `trip = {\"destination\": {\"city\": \"Paris\"}}`.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"trip","t2":"[\"destination\"]","t3":"[\"city\"]"}},"dr-2":{"title":"Build a loop over records","prompt":"Arrange these lines to make a loop that prints each student's name from `students`, a list of dictionaries.","hint":"The loop header comes first, and the indented print line comes after it.","help":{"concept":"To loop through a list of dictionaries, write a `for` loop that takes one dictionary at a time, then access a key from that dictionary inside the loop.","hint_1":"Use `student` as the loop variable for each dictionary in `students`.","hint_2":"After the loop header, the print line should use `student[\"name\"]`."},"tokens":{"t1":"for student in students:","t2":"print(student[\"name\"])"}},"fb-1":{"title":"Fill the missing key","prompt":"Complete the expression so it reads the score from the first dictionary in the list.","hint":"The first part `records[0]` gives you one dictionary.","help":{"concept":"After selecting one dictionary from a list, use the correct key name to read the needed value.","hint_1":"You already have the first record. Now choose the key that stores the numeric result.","hint_2":"Use the dictionary key that names the requested field, not a list index or an unrelated variable."},"template":"records[0][\"[blank1]\"]","choices":["score","records","0","name"]},"fb-2":{"title":"Fill the missing outer key","prompt":"Complete the expression so it reads the list stored inside the dictionary `data = {\"items\": [1, 2, 3]}`.","hint":"You need the key that points to the inner list.","help":{"concept":"When a dictionary stores a list, you use the dictionary key first to get that list.","hint_1":"The list `[1, 2, 3]` is stored under one named key in `data`.","hint_2":"Choose the key that matches the label attached to the list value."},"template":"data[\"[blank1]\"]","choices":["items","data","list","0"]},"code-1":{"title":"Return all names","prompt":"Each item in `records` stores a person's data. Finish `get_names(records)` by adding every record's `\"name\"` value to the `names` list, then return `names`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def get_names(records):\n names = []\n # add each record's name to names\n return names","solutionCode":"def get_names(records):\n names = []\n for record in records:\n names.append(record[\"name\"])\n return names"},"code-2":{"title":"Count total stock","prompt":"Finish `total_stock(items)` so it loops through the item dictionaries, adds each `\"stock\"` value into `total`, and returns the final total.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def total_stock(items):\n total = 0\n # update total using each item's stock\n return total","solutionCode":"def total_stock(items):\n total = 0\n for item in items:\n total += item[\"stock\"]\n return total"},"code-3":{"title":"Find the highest score","prompt":"Finish `highest_score(players)` so it compares each later player's `\"score\"` with `best` and returns the highest score in the list.","hint":"Read the task \"Find the highest score\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def highest_score(players):\n best = players[0][\"score\"]\n # compare later scores with best\n return best","solutionCode":"def highest_score(players):\n best = players[0][\"score\"]\n for player in players:\n if player[\"score\"] > best:\n best = player[\"score\"]\n return best"},"try-nested-data-structures-checkpoint":{"title":"Read nested data","prompt":"Use a list of dictionaries. Print the second student’s name and score.","hint":"Use index `1`, then dictionary keys.","help":{"concept":"Nested data combines containers, such as a list of dictionaries.","hint_1":"Use index `1`, then dictionary keys.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"students = [{\"name\": \"Ava\", \"score\": 88}, {\"name\": \"Mia\", \"score\": 91}]\n\n# Print Mia and her score on separate lines.\n","solutionCode":"students = [{\"name\": \"Ava\", \"score\": 88}, {\"name\": \"Mia\", \"score\": 91}]\nprint(students[1][\"name\"])\nprint(students[1][\"score\"])\n","sourceChecks":{"0":{"message":"Use students[1] to reach Mia instead of typing Mia directly."},"1":{"message":"Use the name key from the student dictionary."},"2":{"message":"Use the score key from the student dictionary."}}},"try-nested-data-structures-sketch0":{"title":"Build records and read the second score","prompt":"Two student names and scores arrive as input. Build `students` as a list containing two dictionaries. Each dictionary must use the keys `\"name\"` and `\"score\"`. Then print the second student's name and score on separate lines by accessing `students[1]` first.","hint":"Build the two dictionaries inside one list, then access the second record with index `1`.","help":{"concept":"A list of dictionaries combines positional access for the outer list with key access for each record.","hint_1":"Create `students = [{\"name\": name1, \"score\": score1}, {\"name\": name2, \"score\": score2}]`.","hint_2":"Print `students[1][\"name\"]` and `students[1][\"score\"]`."},"starterCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\n# Build students as a list of two dictionaries.\n# Print the second student's name using students[1].\n# Print the second student's score using students[1].\n","solutionCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\nstudents = [\n {\"name\": name1, \"score\": score1},\n {\"name\": name2, \"score\": score2}\n]\nprint(students[1][\"name\"])\nprint(students[1][\"score\"])\n","sourceChecks":{"0":{"message":"Use index `1` as requested in the prompt."},"1":{"message":"Use index `1` as requested in the prompt."}}},"try-nested-data-structures-sketch1":{"title":"Update stock inside a nested dictionary","prompt":"The dictionary `product` contains an inner dictionary under the key `\"details\"`. Read a new stock count from input, update only `product[\"details\"][\"stock\"]`, then print the updated stock value.","hint":"Use one key lookup to reach `details`, then another key lookup to reach `stock`.","help":{"concept":"Nested assignment follows the same path as nested reading, with the final lookup placed on the left side of `=`.","hint_1":"Do not replace the whole `details` dictionary.","hint_2":"Assign with `product[\"details\"][\"stock\"] = new_stock`."},"starterCode":"product = {\n \"name\": \"Notebook\",\n \"details\": {\"price\": 4, \"stock\": 12}\n}\nnew_stock = int(input())\n\n# Update only the nested stock value.\n# Print the updated stock value.\n","solutionCode":"product = {\n \"name\": \"Notebook\",\n \"details\": {\"price\": 4, \"stock\": 12}\n}\nnew_stock = int(input())\n\nproduct[\"details\"][\"stock\"] = new_stock\nprint(product[\"details\"][\"stock\"])\n","sourceChecks":{"0":{"message":"Loop through students instead of typing each line directly."},"1":{"message":"Use the name key while building each line."},"2":{"message":"Use the score key while building each line."}}},"try-nested-data-structures-sketch2":{"title":"Add an attendee to a nested list","prompt":"The dictionary `course` stores a list of student names under the key `\"students\"`. Read one new name from input, append that name to `course[\"students\"]`, then print the updated list. Access the student list stored inside `course` under the `students` key, then use `append()` to add `new_student` to that nested list.","hint":"First access the list stored under `\"students\"`, then call `.append()` on that list.","help":{"concept":"When a dictionary value is a list, you can access that list by key and use normal list methods on it.","hint_1":"The input name is stored in `new_student`.","hint_2":"Use `course[\"students\"].append(new_student)`, then print `course[\"students\"]`."},"starterCode":"course = {\"title\": \"Python\", \"students\": [\"Ava\"]}\nnew_student = input()\n\n# Append new_student to the list stored under \"students\".\n# Print the updated students list.\n","solutionCode":"course = {\"title\": \"Python\", \"students\": [\"Ava\"]}\nnew_student = input()\n\ncourse[\"students\"].append(new_student)\nprint(course[\"students\"])\n","sourceChecks":{"0":{"message":"Access the explicitly requested `\"students\"` field from `course`."},"1":{"message":"Use `append()` to add the input name to the nested students list."},"2":{"message":"Print the updated student list stored at `course[\"students\"]` itself."}}},"sc-best-structure":{"title":"Choose a structure for repeated records","prompt":"You need to store several products, and every product has a `name` and a `price`. Which structure best represents that data?","hint":"You need one collection for the whole group and labeled fields for each individual product.","help":{"concept":"A list of dictionaries is a common structure for several records that share the same labeled fields.","hint_1":"The outer list stores all products.","hint_2":"Each dictionary can store one product with keys such as `\"name\"` and `\"price\"`."},"options":{"a":"A list of dictionaries","b":"One long string","c":"A single dictionary for every product combined","d":"One integer"}},"sc-list-then-key":{"title":"Read from a list of dictionaries","prompt":"Given `players = [{\"name\": \"Mia\", \"score\": 7}, {\"name\": \"Leo\", \"score\": 5}]`, which expression gets Leo's score?","hint":"Select the second dictionary first, then read its `\"score\"` key.","help":{"concept":"For a list of dictionaries, access happens in layers: list index first, dictionary key second.","hint_1":"Leo is the second list item, so use index `1`.","hint_2":"Then use `['score']` on that dictionary."},"options":{"a":"players[1][\"score\"]","b":"players[\"score\"][1]","c":"players[1][1]","d":"players[\"Leo\"][\"score\"]"}},"sc-dict-then-key":{"title":"Read from a dictionary inside a dictionary","prompt":"Given `item = {\"name\": \"Pen\", \"info\": {\"price\": 2, \"stock\": 9}}`, which expression gets the stock value?","hint":"Open the outer `\"info\"` field before reading `\"stock\"` from the inner dictionary.","help":{"concept":"A dictionary nested inside another dictionary is read with one key lookup per layer.","hint_1":"`item[\"info\"]` gives the inner dictionary.","hint_2":"Then add `[\"stock\"]`."},"options":{"a":"item[\"info\"][\"stock\"]","b":"item[\"stock\"]","c":"item[0][\"stock\"]","d":"item[\"name\"][\"stock\"]"}},"sc-loop-record":{"title":"Understand the loop variable","prompt":"If `students` is a list of dictionaries, what does `student` hold during `for student in students:`?","hint":"The loop visits one item from the outer list at a time.","help":{"concept":"When a list contains dictionaries, the loop variable receives one whole dictionary record on each iteration.","hint_1":"`student` is not only a name or score.","hint_2":"Inside the loop you can read fields such as `student[\"name\"]`."},"options":{"a":"One student dictionary at a time","b":"Only the student's name","c":"Only the list index","d":"The entire students list every time"}},"try-nested-data-structures-sketch3":{"title":"Loop through dynamic student records","prompt":"Two student names and scores arrive as input. Build `students` as a list of two dictionaries using the keys `\"name\"` and `\"score\"`. Loop through `students` so `student` receives one dictionary at a time. Print each record exactly as `name: score`.","hint":"Build the records first, then use one loop over `students` and read both keys from the current `student`.","help":{"concept":"A loop over a list of dictionaries processes one whole record per iteration.","hint_1":"Use `for student in students:`.","hint_2":"Inside the loop, print `f\"{student['name']}: {student['score']}\"`."},"starterCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\n# Build students as a list of two dictionaries.\n# Loop through students.\n# Print each student as: name: score\n","solutionCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\nstudents = [\n {\"name\": name1, \"score\": score1},\n {\"name\": name2, \"score\": score2}\n]\nfor student in students:\n print(f\"{student['name']}: {student['score']}\")\n","sourceChecks":{"0":{"message":"Use a `for` loop over `students` as the prompt requests."}}}},"tryIt":{"try_nested_data_structures_checkpoint":{"title":"Try it yourself","prompt":"Use a list of dictionaries. Print the second student’s name and score."},"try_nested_data_structures_sketch0":{"title":"Try it yourself","prompt":"Build two student dictionaries inside a list, then read the second record by index and key."},"try_nested_data_structures_sketch1":{"title":"Try it yourself","prompt":"Update a stock value stored inside a nested dictionary."},"try_nested_data_structures_sketch2":{"title":"Try it yourself","prompt":"The dictionary `course` stores a list of student names under the key `\"students\"`. Read one new name from input, append that name to `course[\"students\"]`, then print the updated list. Access the student list stored inside `course` under the `students` key, then use `append()` to add `new_student` to that nested list."},"allowReveal":true,"try_nested_data_structures_sketch3":{"title":"Try it yourself","prompt":"Build student records from input and loop through the list one dictionary at a time."}}},"tuple-records-and-unpacking":{"label":"Tuple Records and Unpacking","summary":"Use tuples for fixed-shape records, read fields by position, unpack fields into meaningful names, and process tuple records in a loop.","cards":{"sketch0":{"title":"Tuples as fixed-shape records"},"sketch1":{"title":"Unpacking fields into names"},"quiz":{"title":"Check your understanding"},"sketch2":{"title":"Looping through tuple records"}},"quiz":{"try-tuple-records-sketch0":{"title":"Build and read a shipment record","prompt":"A product name and quantity arrive as input. Create a tuple named `shipment` containing `product` first and `quantity` second. Then print the product using index `0` and the quantity using index `1`, each on its own line. Create a tuple named `shipment` containing `product` first and `quantity` second. Then use tuple indexing to read and print the first field followed by the second field.","hint":"Create one two-field tuple from the input variables, then read its two positions.","help":{"concept":"A tuple can hold related fields in a fixed order, and tuple indexes work like list indexes.","hint_1":"Build `shipment = (product, quantity)`.","hint_2":"Print `shipment[0]`, then `shipment[1]`."},"starterCode":"product = input()\nquantity = int(input())\n\n# Create shipment as a two-field tuple: product, then quantity.\n# Print the product using index 0.\n# Print the quantity using index 1.\n","solutionCode":"product = input()\nquantity = int(input())\n\nshipment = (product, quantity)\nprint(shipment[0])\nprint(shipment[1])\n","sourceChecks":{"0":{"message":"Create `shipment` as the tuple `(product, quantity)`."},"1":{"message":"Use index `0` to read the first tuple field."},"2":{"message":"Use index `1` to read the second tuple field."}}},"try-tuple-unpacking-sketch1":{"title":"Unpack a booking record","prompt":"A booking record is already stored as the provided `booking` value is a three-field tuple containing a workshop title, seat count, and day. Unpack the tuple into `title`, `seats`, and `day` in one assignment. Print the three variables on separate lines in that order. Unpack `booking` into the variables `title`, `seats`, and `day` in that order before printing the three values. Do not hard-code the known output.","hint":"The tuple has three fields, so use three target names on the left side of one assignment.","help":{"concept":"Unpacking replaces positional lookups with meaningful variable names.","hint_1":"Write `title, seats, day = booking`.","hint_2":"After unpacking, print `title`, `seats`, and `day` instead of hard-coding the values."},"starterCode":"booking = (\"Workshop\", 24, \"Friday\")\n\n# Unpack booking into title, seats, and day.\n# Print title, seats, and day on separate lines.\n","solutionCode":"booking = (\"Workshop\", 24, \"Friday\")\n\ntitle, seats, day = booking\nprint(title)\nprint(seats)\nprint(day)\n","sourceChecks":{"0":{"message":"Unpack the tuple with `title, seats, day = booking` before printing the fields."}}},"sc-tuple-purpose":{"title":"Choose a fixed-shape record","prompt":"A coordinate always has exactly two ordered fields: x and y. Which value best communicates that fixed two-field shape?","options":{"a":"[4, 9]","b":"(4, 9)","c":"{\"x\": 4, \"y\": 9}","d":"\"4, 9\""},"hint":"Use the collection type intended for an ordered record whose fields should not be changed in place.","help":{"concept":"A tuple is useful when a small ordered record has a stable shape.","hint_1":"A list is better when items are expected to be added, removed, or replaced.","hint_2":"Choose the value written with parentheses."}},"mc-tuple-facts":{"title":"Recognize tuple behavior","prompt":"Which statements about tuples are true?","options":{"a":"Tuple positions use zero-based indexes.","b":"append() adds a value to an existing tuple.","c":"A tuple can be unpacked into multiple names.","d":"Tuples can contain only strings."},"hint":"Separate how a tuple is read from whether its structure can be mutated.","help":{"concept":"Tuples are ordered and indexable, but they do not support list-style mutation methods.","hint_1":"Unpacking follows position order.","hint_2":"A tuple may hold values of different types."}},"fb-tuple-index":{"title":"Read the first tuple field","prompt":"Complete the expression that reads `\"North\"` from `direction = (\"North\", 12)`: `direction[___]`","options":{"a":"0","b":"1","c":"-2 + 1"},"hint":"Tuple indexing begins at the same position as list and string indexing.","help":{"concept":"Every Python sequence begins with the zero index.","hint_1":"The requested value is the first field.","hint_2":"Use the simplest direct index."}},"dr-tuple-unpack":{"title":"Build an unpacking assignment","prompt":"Arrange the tokens to unpack `record` into `name` and `score`.","tokens":{"t1":"name","t2":",","t3":"score","t4":"=","t5":"record"},"hint":"Put the target names on the left and the tuple variable on the right.","help":{"concept":"Unpacking is one assignment with one target name per tuple position.","hint_1":"The comma separates the two target names.","hint_2":"The tuple variable appears after the equals sign."}},"sc-tuple-immutable":{"title":"Recognize an invalid tuple mutation","prompt":"Given `point = (4, 9)`, which line tries to mutate the tuple and therefore cannot be used?","hint":"Tuples can be read and unpacked, but their existing positions cannot be reassigned.","help":{"concept":"Tuple values are ordered and indexable, but the tuple itself is immutable.","hint_1":"`point[0]` can be read.","hint_2":"Assigning a new value to `point[0]` attempts to change the tuple in place."},"options":{"a":"print(point[0])","b":"x, y = point","c":"point[0] = 7","d":"print(point)"}},"sc-unpack-shape":{"title":"Match names to tuple fields","prompt":"Given `student = (\"Ava\", 91, \"A\")`, which line correctly unpacks all three fields?","hint":"Unpacking needs one target name for each tuple position.","help":{"concept":"Tuple unpacking assigns positions from left to right into the same number of target names.","hint_1":"This tuple contains three fields.","hint_2":"Choose the assignment with three names on the left side."},"options":{"a":"name, score, grade = student","b":"name, score = student","c":"student = name, score, grade","d":"name = student"}},"sc-loop-unpack":{"title":"Unpack each record in a loop","prompt":"Given `registrations = [(\"Ava\", 2), (\"Noah\", 1)]`, which loop header gives meaningful names to both fields of each tuple?","hint":"Each item in `registrations` is a two-field tuple.","help":{"concept":"A `for` loop can unpack each tuple item directly into one variable per field.","hint_1":"Each record contains a name and a seat count.","hint_2":"Use `for name, seats in registrations:`."},"options":{"a":"for name, seats in registrations:","b":"for registrations in name, seats:","c":"for name in seats:","d":"for 0, 1 in registrations:"}},"try-tuple-loop-sketch2":{"title":"Build and loop through registration records","prompt":"Two registrations arrive as a name followed by a seat count. Create `registrations` as a list containing two tuples: `(name1, seats1)` and `(name2, seats2)`. Loop through the list by unpacking each tuple into `name` and `seats`, then print `name` and `seats` on one line for each registration.","hint":"Build a list of two tuple records first, then unpack each record directly in the `for` loop header.","help":{"concept":"A list can hold several fixed-shape tuple records, and a loop can unpack each record as it visits it.","hint_1":"Create `registrations = [(name1, seats1), (name2, seats2)]`.","hint_2":"Use `for name, seats in registrations:` and print the two current fields."},"starterCode":"name1 = input()\nseats1 = int(input())\nname2 = input()\nseats2 = int(input())\n\n# Create registrations as a list of two (name, seats) tuples.\n# Loop through registrations and unpack each tuple into name and seats.\n# Print name and seats on one line for each record.\n","solutionCode":"name1 = input()\nseats1 = int(input())\nname2 = input()\nseats2 = int(input())\n\nregistrations = [(name1, seats1), (name2, seats2)]\nfor name, seats in registrations:\n print(name, seats)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `registrations` as the prompt requests."}}}},"tryIt":{"try_tuple_records_sketch0":{"title":"Try it yourself","prompt":"A product name and quantity arrive as input. Create a tuple named `shipment` containing `product` first and `quantity` second. Then print the product using index `0` and the quantity using index `1`, each on its own line. Create a tuple named `shipment` containing `product` first and `quantity` second. Then use tuple indexing to read and print the first field followed by the second field."},"try_tuple_unpacking_sketch1":{"title":"Try it yourself","prompt":"A booking record is already stored as the provided `booking` value is a three-field tuple containing a workshop title, seat count, and day. Unpack the tuple into `title`, `seats`, and `day` in one assignment. Print the three variables on separate lines in that order. Unpack `booking` into the variables `title`, `seats`, and `day` in that order before printing the three values. Do not hard-code the known output."},"allowReveal":true,"try_tuple_loop_sketch2":{"title":"Try it yourself","prompt":"Build two tuple records from input, store them in a list, and unpack each record in a loop."}},"practice":{"practice-unpack-name-score":{"title":"Unpack a name and score record","prompt":"Read a name and a whole-number score. Store them together in a tuple named `record`, unpack the tuple into `name` and `score`, then print `NAME: SCORE`.","hint":"Create `(name_input, score_input)`, then assign `name, score = record`.","help":{"concept":"Tuple unpacking assigns each fixed record field to a matching variable in one statement.","hint_1":"Create `(name_input, score_input)`, then assign `name, score = record`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"name_input = input().strip()\nscore_input = int(input())\n\n# Build record, unpack it, and print NAME: SCORE.\n","starterFiles":{"main_py":{"content":"name_input = input().strip()\nscore_input = int(input())\n\n# Build record, unpack it, and print NAME: SCORE.\n"}},"solutionCode":"name_input = input().strip()\nscore_input = int(input())\nrecord = (name_input, score_input)\nname, score = record\nprint(f\"{name}: {score}\")\n","solutionFiles":{"main_py":{"content":"name_input = input().strip()\nscore_input = int(input())\nrecord = (name_input, score_input)\nname, score = record\nprint(f\"{name}: {score}\")\n"}}},"practice-tuple-first-and-last":{"title":"Read fields from a tuple record","prompt":"Read a city, a day, and a temperature. Store them as `(city, day, temperature)` in `record`, then print the first field and the last field on separate lines using tuple indexes.","hint":"The first field is index `0`; the last field can be accessed with `-1`.","help":{"concept":"A tuple keeps record fields in a stable order, so indexes can retrieve known positions directly.","hint_1":"The first field is index `0`; the last field can be accessed with `-1`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\n\n# Build record and print its first and last fields.\n","starterFiles":{"main_py":{"content":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\n\n# Build record and print its first and last fields.\n"}},"solutionCode":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\nrecord = (city, day, temperature)\nprint(record[0])\nprint(record[-1])\n","solutionFiles":{"main_py":{"content":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\nrecord = (city, day, temperature)\nprint(record[0])\nprint(record[-1])\n"}}},"practice-loop-unpack-two-records":{"title":"Loop through tuple records with unpacking","prompt":"Read two names and two scores. Build a list containing two `(name, score)` tuples. Loop with `for name, score in records:` and print each record as `NAME -> SCORE`.","hint":"Build two tuples first, then unpack each tuple directly in the `for` loop header.","help":{"concept":"A loop can unpack each tuple record as it is visited, giving clear names to the fields without separate index lookups.","hint_1":"Build two tuples first, then unpack each tuple directly in the `for` loop header.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\n\n# Build two tuple records and loop through them with unpacking.\n","starterFiles":{"main_py":{"content":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\n\n# Build two tuple records and loop through them with unpacking.\n"}},"solutionCode":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\nrecords = [(name1, score1), (name2, score2)]\nfor name, score in records:\n print(f\"{name} -> {score}\")\n","solutionFiles":{"main_py":{"content":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\nrecords = [(name1, score1), (name2, score2)]\nfor name, score in records:\n print(f\"{name} -> {score}\")\n"}}}}},"updating-and-looping-dictionaries":{"label":"Updating and Looping Dictionaries","summary":"Add or update dictionary entries, remove keys safely, loop through keys or key-value pairs, and build a dictionary from repeated data.","cards":{"sketch0":{"title":"Adding and updating entries"},"sketch1":{"title":"Removing a key safely"},"sketch2":{"title":"Looping through dictionary keys"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Looping through key-value pairs"},"sketch4":{"title":"Building a dictionary in a loop"}},"quiz":{"sc-dict-update-existing":{"title":"Updating an existing key","prompt":"What happens in Python when you run `profile[\"age\"] = 13` and the key `\"age\"` is already in the dictionary?","hint":"Assignment with an existing key replaces that key's old value.","help":{"concept":"Dictionary assignment uses the key to decide where the value goes. If the key already exists, Python keeps the key and changes only its stored value.","hint_1":"This is not a list index operation. Python looks up the key `\"age\"` in the dictionary.","hint_2":"Ask whether the key is new or already present. Existing keys are changed, not duplicated."},"options":{"a":"It updates the value stored for `\"age\"`","b":"It creates a second separate `\"age\"` entry","c":"It removes the `\"age\"` key","d":"It turns the dictionary into a list"}},"sc-loop-direct-dict":{"title":"What direct dictionary iteration gives you","prompt":"If `colors = {\"red\": 1, \"blue\": 2}`, what does `for color in colors:` store in `color` on each iteration?","hint":"A plain loop over a dictionary visits its lookup labels.","help":{"concept":"Direct dictionary iteration yields one key at a time.","hint_1":"The keys are `\"red\"` and `\"blue\"`.","hint_2":"To obtain the matching value inside the loop, you could use `colors[color]`."},"options":{"a":"Each key, such as `\"red\"` and `\"blue\"`","b":"Each value, such as `1` and `2`","c":"A key and value pair automatically","d":"The dictionary length"}},"mc-valid-dict-changes":{"title":"Ways to change a dictionary","prompt":"Which statements can change the contents of a dictionary named `stock`? Choose all that apply.","hint":"Think about adding or updating with square brackets, and removing with `del`.","help":{"concept":"Dictionaries can be changed by assigning to a key or deleting a key. Reading a value or printing the dictionary does not modify it.","hint_1":"Look for statements that either store a value into `stock[...]` or remove a key from `stock`.","hint_2":"One correct choice adds or updates a key, and another correct choice removes a key entirely."},"options":{"a":"`stock[\"pens\"] = 12`","b":"`del stock[\"pens\"]`","c":"`print(stock[\"pens\"])`","d":"`len(stock)`"}},"mc-items-loop":{"title":"Using `.items()`","prompt":"Which statements about `for key, value in data.items():` are correct? Choose all that apply.","hint":"Focus on what `.items()` provides to the loop.","help":{"concept":"The `.items()` method gives key-value pairs, so the loop can unpack each pair into two variables.","hint_1":"Check whether the loop receives one thing or two things from each dictionary entry.","hint_2":"Two statements are true: one about getting both parts of each entry, and one about the meaning of `key` and `value`."},"options":{"a":"It lets you work with both the key and the value in each loop","b":"`key` stores the dictionary key for the current pair","c":"It only works for lists, not dictionaries","d":"It removes entries as it loops"}},"dr-update-sequence":{"title":"Order the dictionary changes","prompt":"Put these lines in the correct order to create a dictionary, update one value, add one new key, and print the result.","hint":"Start by creating the dictionary before trying to change it.","help":{"concept":"A dictionary must exist before you can update or add entries. After the changes, printing shows the final state.","hint_1":"The dictionary literal line comes first, and `print` comes last.","hint_2":"Between those, update the existing `\"tea\"` key and add the new `\"juice\"` key."},"tokens":{"t1":"drinks = {\"tea\": 2}","t2":"drinks[\"tea\"] = 3","t3":"drinks[\"juice\"] = 1","t4":"print(drinks)"}},"dr-loop-items-order":{"title":"Build a loop with `.items()`","prompt":"Arrange the tokens to make a loop that prints each key and value from `scores`.","hint":"The loop header comes first, then the indented print line.","help":{"concept":"A dictionary loop with `.items()` uses `for key, value in scores.items():` and then an indented statement inside the loop.","hint_1":"Use `.items()` in the loop header so both variables receive data.","hint_2":"After the colon, the next line should be indented and print both loop variables."},"tokens":{"t1":"for name, score in scores.items():","t2":"print(name, score)"}},"fb-remove-key":{"title":"Remove a dictionary entry","prompt":"Choose the missing code to remove the key `\"done\"` from the dictionary.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"[blank1] tasks[\"done\"]","choices":["del","print","return","for"]},"fb-items-method":{"title":"Complete the loop method","prompt":"Choose the missing method so the loop gets both keys and values.","hint":"Use the dictionary method that returns key-value pairs.","help":{"concept":"Choose the dictionary method that yields key-value pairs so each pair can be unpacked into two loop variables.","hint_1":"Methods like `.keys()` and `.values()` give only one part each.","hint_2":"You need the method that matches `for key, value in ...`."},"template":"for key, value in data.[blank1]():","choices":["items","keys","values","append"]},"ci-update-score":{"title":"Update one score and return the dictionary","prompt":"Write `update_score(scores, name, new_score)` so it updates the existing entry for `name` or adds it if it is missing, then returns the `scores` dictionary.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def update_score(scores, name, new_score):\n # update or add the score, then return the dictionary\n pass","solutionCode":"def update_score(scores, name, new_score):\n scores[name] = new_score\n return scores"},"ci-remove-key":{"title":"Remove a key if it exists","prompt":"Write `remove_item(data, key_name)` so it removes `key_name` from the dictionary when that key is present, then returns the dictionary.","hint":"Read the task \"Remove a key if it exists\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def remove_item(data, key_name):\n # remove the key when it is present, then return the dictionary\n pass","solutionCode":"def remove_item(data, key_name):\n if key_name in data:\n del data[key_name]\n return data"},"ci-format-items":{"title":"Build lines from dictionary pairs","prompt":"Write `format_inventory(items)` so it builds and returns a list of strings in the format `\"name: count\"`, such as `\"pens: 3\"`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def format_inventory(items):\n # return a list like [\"pens: 3\", \"paper: 2\"]\n result = []\n \n return result","solutionCode":"def format_inventory(items):\n result = []\n for name, count in items.items():\n result.append(f\"{name}: {count}\")\n return result"},"try-updating-and-looping-dictionaries-checkpoint":{"title":"Update and loop through scores","prompt":"Update Mia’s score to `91`, then print each name and score as `name: score`.","hint":"Assign to `scores[\"Mia\"]`, then loop with `.items()`.","help":{"concept":"Dictionaries can be updated by assigning to an existing key.","hint_1":"Assign to `scores[\"Mia\"]`, then loop with `.items()`.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"scores = {\"Ava\": 88, \"Mia\": 79}\n\n# Update Mia to 91.\n# Print each name and score.\n","solutionCode":"scores = {\"Ava\": 88, \"Mia\": 79}\nscores[\"Mia\"] = 91\nfor name, score in scores.items():\n print(f\"{name}: {score}\")\n","sourceChecks":{"0":{"message":"Update scores['Mia'] to 91 instead of printing the final result directly."}}},"try-updating-and-looping-dictionaries-sketch0":{"title":"Add or update stock from input","prompt":"The dictionary `stock` already contains counts for pens and paper. Read an item name and an integer amount from input. Store `amount` under the key in `item` using dictionary assignment, then print the updated dictionary. Your code must work whether the input key already exists or is new. Update `stock` by using the value in `item` as the dictionary key and the value in `amount` as that key's value. This exercise is specifically about dictionary assignment by key.","hint":"Use the input variable itself as the key: `stock[item] = amount`.","help":{"concept":"Dictionary assignment uses the same syntax for both adding a new key and updating an existing one.","hint_1":"Do not write separate code for `\"pens\"` and new item names.","hint_2":"Assign `amount` to `stock[item]`, then print `stock`."},"starterCode":"stock = {\"pens\": 4, \"paper\": 2}\nitem = input()\namount = int(input())\n\n# Store amount under the key in item.\n# Print the updated stock dictionary.\n","solutionCode":"stock = {\"pens\": 4, \"paper\": 2}\nitem = input()\namount = int(input())\n\nstock[item] = amount\nprint(stock)\n","sourceChecks":{"0":{"message":"Store the input amount with `stock[item] = amount` as requested."},"1":{"message":"Print the updated `stock` dictionary itself after changing it."}}},"try-updating-and-looping-dictionaries-sketch1":{"title":"Remove an optional setting","prompt":"The dictionary `settings` contains three keys. Read a key from input. If that key exists, remove it with `del`. If it does not exist, leave the dictionary unchanged. Print the final dictionary.","hint":"Guard the deletion with `if key in settings:`.","help":{"concept":"Checking membership before `del` lets the same program handle present and missing keys safely.","hint_1":"Use `key in settings` as the condition.","hint_2":"Inside the `if` block, write `del settings[key]`. Print the dictionary after the condition."},"starterCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\n# If key exists in settings, remove that entry with del.\n# Print the final settings dictionary.\n","solutionCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\nif key in settings:\n del settings[key]\nprint(settings)\n","sourceChecks":{"0":{"message":"Loop through inventory instead of typing the inventory lines directly."}}},"try-updating-and-looping-dictionaries-sketch2":{"title":"Loop through keys and look up each value","prompt":"The dictionary `inventory` is already defined. Loop directly through `inventory` so the loop variable receives one key at a time. For each key, print the key and its matching value on one line. Use a `for` loop directly over `inventory`. For each key produced by the loop, use dictionary indexing to retrieve and print its matching value.","hint":"Use `for item in inventory:` and retrieve the current value with `inventory[item]`.","help":{"concept":"A direct dictionary loop yields keys; use the current key to look up its value.","hint_1":"The loop header should not call `.items()` in this exercise.","hint_2":"Inside the loop, print `item` and `inventory[item]`."},"starterCode":"inventory = {\"pens\": 3, \"markers\": 2, \"folders\": 5}\n\n# Loop directly through inventory so item receives each key.\n# Print the current key and inventory[item] on one line.\n","solutionCode":"inventory = {\"pens\": 3, \"markers\": 2, \"folders\": 5}\n\nfor item in inventory:\n print(item, inventory[item])\n","sourceChecks":{"0":{"message":"Loop directly over `inventory` instead of typing the known output."},"1":{"message":"Use `inventory[item]` to retrieve each current key's value."},"2":{"message":"Store each length with lengths[word] = len(word)."}}},"sc-add-or-update":{"title":"Use one assignment for add or update","prompt":"What does `stock[item] = amount` do when `item` is used as a dictionary key?","hint":"The same square-bracket assignment works whether the key already exists or not.","help":{"concept":"Dictionary assignment adds a new key when it is missing and updates the value when the key already exists.","hint_1":"Python checks whether the key stored in `item` is already present in `stock`.","hint_2":"A missing key is added; an existing key receives the new value."},"options":{"a":"It adds the key if missing or updates its value if it already exists","b":"It can only add new keys","c":"It can only change existing keys","d":"It removes the key from the dictionary"}},"sc-safe-delete":{"title":"Remove a key only when it exists","prompt":"Which pattern safely removes the key stored in `key` from `settings` only when that key exists?","hint":"Check membership before using `del`.","help":{"concept":"A membership check can guard a deletion so a missing key does not cause an error.","hint_1":"Use `key in settings` as the condition.","hint_2":"Place `del settings[key]` inside that `if` block."},"options":{"a":"if key in settings:\n del settings[key]","b":"if settings[key]:\n del key","c":"settings.remove(key)","d":"del key in settings"}},"sc-items-loop":{"title":"Get keys and values together","prompt":"Which loop header gives both the key and value from each entry in `scores`?","hint":"Use the dictionary method that provides key-value pairs.","help":{"concept":"`.items()` provides each dictionary entry as a key-value pair that can be unpacked into two loop variables.","hint_1":"The loop needs two variables because each item contains two pieces.","hint_2":"Use `for name, score in scores.items():`."},"options":{"a":"for name, score in scores.items():","b":"for name, score in scores:","c":"for score in scores.values, names:","d":"for scores.items() in name, score:"}},"try-updating-and-looping-dictionaries-sketch3":{"title":"Print dynamic score pairs with .items()","prompt":"Two student names and scores arrive as input. Build a dictionary named `scores` from those two pairs. Then loop through the dictionary's `items()` method by unpacking each pair into `name` and `score`. Print each entry exactly as `name: score`.","hint":"Build the dictionary first, then use `for name, score in scores.items():`.","help":{"concept":"`.items()` lets a loop work with the key and value together without a separate lookup.","hint_1":"Create `scores = {name1: score1, name2: score2}`.","hint_2":"In the loop, print `f\"{name}: {score}\"`."},"starterCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\n# Create scores from the two name/score pairs.\n# Loop through scores.items() as name, score.\n# Print each entry as: name: score\n","solutionCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\nscores = {name1: score1, name2: score2}\nfor name, score in scores.items():\n print(f\"{name}: {score}\")\n","sourceChecks":{"0":{"message":"Use a `for` loop over `scores` as the prompt requests."}}},"try-updating-and-looping-dictionaries-sketch4":{"title":"Build word lengths in a dictionary","prompt":"Three words arrive as input. Store them in a list named `words`. Create an empty dictionary named `lengths`. Loop through `words` and store each word as a key with `len(word)` as its value. Print the completed `lengths` dictionary.","hint":"Inside the loop, assign to a dictionary key with `lengths[word] = len(word)`.","help":{"concept":"A loop can build a dictionary one key-value pair at a time.","hint_1":"Create `words` from the three inputs and initialize `lengths = {}` before the loop.","hint_2":"For each `word`, store its calculated length with `lengths[word] = len(word)`."},"starterCode":"first = input()\nsecond = input()\nthird = input()\n\n# Create words from the three input values.\n# Create an empty dictionary named lengths.\n# Loop through words and store each word's length.\n# Print lengths.\n","solutionCode":"first = input()\nsecond = input()\nthird = input()\n\nwords = [first, second, third]\nlengths = {}\nfor word in words:\n lengths[word] = len(word)\nprint(lengths)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `words` as the prompt requests."}}}},"tryIt":{"try_updating_and_looping_dictionaries_checkpoint":{"title":"Try it yourself","prompt":"Update Mia’s score to `91`, then print each name and score as `name: score`."},"try_updating_and_looping_dictionaries_sketch0":{"title":"Try it yourself","prompt":"The dictionary `stock` already contains counts for pens and paper. Read an item name and an integer amount from input. Store `amount` under the key in `item` using dictionary assignment, then print the updated dictionary. Your code must work whether the input key already exists or is new. Update `stock` by using the value in `item` as the dictionary key and the value in `amount` as that key's value. This exercise is specifically about dictionary assignment by key."},"try_updating_and_looping_dictionaries_sketch1":{"title":"Try it yourself","prompt":"Remove an input key from `settings` only when that key exists."},"try_updating_and_looping_dictionaries_sketch2":{"title":"Try it yourself","prompt":"The dictionary `inventory` is already defined. Loop directly through `inventory` so the loop variable receives one key at a time. For each key, print the key and its matching value on one line. Use a `for` loop directly over `inventory`. For each key produced by the loop, use dictionary indexing to retrieve and print its matching value."},"allowReveal":true,"try_updating_and_looping_dictionaries_sketch3":{"title":"Try it yourself","prompt":"Two student names and scores arrive as input. Build a dictionary named `scores` from those two pairs. Then loop through the dictionary's `items()` method by unpacking each pair into `name` and `score`. Print each entry exactly as `name: score`."},"try_updating_and_looping_dictionaries_sketch4":{"title":"Try it yourself","prompt":"Build a word-length dictionary one entry at a time inside a loop."}}}},"python-6-functions-and-modularity":{"decomposition-and-refactoring":{"label":"Decomposition and Refactoring","summary":"Refactor working code by extracting repeated or separate responsibilities into helper functions while preserving the program's behavior.","cards":{"sketch0":{"title":"Extract repeated work into one helper"},"sketch1":{"title":"Move one responsibility out of the main flow"},"sketch2":{"title":"Reuse helpers instead of duplicating their logic"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-1":{"title":"Best reason to extract a helper","prompt":"Which situation is the strongest reason to move code into a helper function?","hint":"Look for repeated logic that does the same job in more than one place.","help":{"concept":"Helper functions are especially useful when the same logic appears multiple times, because one function can replace repeated code and make updates easier.","hint_1":"Compare the choices and find the one where the same steps would otherwise be copied.","hint_2":"A helper is most valuable when one reusable task appears in several places, not just because a program has many lines."},"options":{"a":"A variable name is short","b":"The same cleanup steps are written in several places","c":"The program uses input() once","d":"A print statement appears at the end"}},"sc-2":{"title":"What refactoring should preserve","prompt":"When you refactor a working program, what should stay the same?","hint":"Refactoring changes structure, not the program's intended result.","help":{"concept":"Refactoring improves readability or organization while preserving behavior, so the program should still produce the same results for the same inputs.","hint_1":"Think about what users notice: the program should still solve the same problem correctly.","hint_2":"The code layout may change, but the output and behavior for the same input should not change."},"options":{"a":"The number of functions must decrease","b":"The variable names must stay identical","c":"The program's behavior for the same input should remain correct","d":"Every line must stay in the same order"}},"mc-1":{"title":"Signs a function is doing too much","prompt":"Which choices suggest a function should be split into smaller helpers? Choose all that apply.","hint":"Look for mixed responsibilities and repeated chunks of logic.","help":{"concept":"A function often needs decomposition when it handles several different jobs or contains repeated logic that could be reused elsewhere.","hint_1":"One clue is that the function both transforms data and formats final output in a long block.","hint_2":"Another clue is seeing nearly identical code chunks or a function that tries to clean, calculate, and display all at once."},"options":{"a":"It cleans text, calculates a result, and formats a message in one long block","b":"It contains repeated code chunks with only small changes","c":"It has one short return statement for one clear task","d":"It is hard to describe the function's job in one sentence"}},"mc-2":{"title":"Benefits of helper functions","prompt":"Which are real benefits of breaking code into helper functions? Choose all that apply.","hint":"Think about readability, reuse, and testing.","help":{"concept":"Helper functions improve organization by giving small tasks clear names, reducing duplication, and making logic easier to test separately.","hint_1":"Useful helpers usually make code easier to read and let you reuse one piece of logic in multiple places.","hint_2":"They also help you test one small behavior at a time; they do not automatically make every program shorter in line count."},"options":{"a":"You can reuse the same logic from multiple places","b":"Small pieces are easier to test one at a time","c":"Every program will always use fewer total lines","d":"Function names can explain what each step does"}},"dr-1":{"title":"Refactor repeated cleanup","prompt":"Put these steps in the best order for refactoring repeated text-cleaning code into a helper function.","hint":"First identify the repeated task, then define the helper, then replace the duplicates.","help":{"concept":"A clean refactor usually starts by noticing repeated logic, extracting it into a function, and then calling that function where needed.","hint_1":"You should not replace old code with helper calls before the helper exists.","hint_2":"The repeated behavior must be identified first, then moved into a function, then used from the original locations."},"tokens":{"t1":"Notice the same cleanup logic appears more than once","t2":"Write a helper function for that cleanup task","t3":"Replace the repeated code with calls to the helper","t4":"Run the program and confirm the behavior still matches"}},"dr-2":{"title":"How a helper-based program flows","prompt":"Arrange the steps in the order they happen when this pattern runs: input is cleaned, then used to build a message, then printed.","hint":"A helper returns a value before the next function uses it.","help":{"concept":"In decomposed code, one function often returns a cleaned value, another function uses that value to build a result, and then the main code prints the final result.","hint_1":"The cleaned text must exist before a greeting or summary can be built from it.","hint_2":"Printing is usually the last step after helper functions have returned the needed values."},"tokens":{"t1":"Call the cleaning helper with the original text","t2":"Receive the cleaned text as a return value","t3":"Use the cleaned text to build the final message","t4":"Print the final message"}},"fb-1":{"title":"Call the helper","prompt":"Choose the function call that uses the helper to clean the variable `name`.","hint":"The blank should be a call that passes `name` into the helper.","help":{"concept":"To use a helper function, write its name followed by parentheses and pass the needed argument inside.","hint_1":"You are filling the right side of an assignment, so the blank should produce a value.","hint_2":"Look for the choice that calls `clean_name` with `name` inside the parentheses."},"template":"nice_name = [blank1]","choices":["clean_name(name)","name = clean_name","print(name)","return clean_name"]},"fb-2":{"title":"Return from a helper","prompt":"Choose the missing word that sends the computed value back from the function.","hint":"Inside a function, one keyword sends a value back to the caller.","help":{"concept":"A helper function should send its result back so other code can store, display, or combine that value.","hint_1":"`print` shows text in the output panel, but it does not send a reusable value back to the caller.","hint_2":"The missing word is the keyword used before an expression like `text.strip()` when the function should produce a value."},"template":"def clean_text(text):\n [blank1] text.strip().lower()","choices":["return","print","input","def"]},"ci-1":{"title":"Extract a cleaning helper","prompt":"Write `clean_name(name)` so it returns the cleaned version of `name`. This helper should do the name-cleaning work instead of leaving it repeated elsewhere.","hint":"Read the task \"Extract a cleaning helper\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def clean_name(name):\n # return the cleaned version of name\n pass","solutionCode":"def clean_name(name):\n return name.strip().title()"},"ci-2":{"title":"Build a summary with helpers","prompt":"Split this job into two helpers. `word_count(text)` should return the number of words, and `summary(text)` should call that helper and return a string like `Words: 3`.","hint":"Read the task \"Build a summary with helpers\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def word_count(text):\n # return the number of words\n pass\n\n\ndef summary(text):\n # return a string like: Words: 3\n pass","solutionCode":"def word_count(text):\n return len(text.split())\n\n\ndef summary(text):\n count = word_count(text)\n return f\"Words: {count}\""},"ci-3":{"title":"Refactor repeated math into helpers","prompt":"Finish `double(number)` and `triple(number)`, then use those helper functions inside `combined_total(a, b)` instead of repeating the math there.","hint":"Read the task \"Refactor repeated math into helpers\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def double(number):\n pass\n\n\ndef triple(number):\n pass\n\n\ndef combined_total(a, b):\n # use the helper functions here\n pass","solutionCode":"def double(number):\n return number * 2\n\n\ndef triple(number):\n return number * 3\n\n\ndef combined_total(a, b):\n return double(a) + triple(b)"},"try-decomposition-and-refactoring-checkpoint":{"title":"Use a helper function","prompt":"Define `clean_title(text)` that strips spaces and title-cases the text. Print the cleaned version of `\" python helper \"`.","hint":"Use `.strip().title()` inside a helper function.","help":{"concept":"Decomposition means moving one clear step into a helper function.","hint_1":"Use `.strip().title()` inside a helper function.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def clean_title(text):\n # Return the cleaned title.\n pass\n\nprint(clean_title(\" python helper \"))\n","solutionCode":"def clean_title(text):\n return text.strip().title()\n\nprint(clean_title(\" python helper \"))\n"},"try-decomposition-and-refactoring-sketch0":{"title":"Refactor repeated name cleanup","prompt":"This program already produces the correct output, but it repeats whitespace trimming followed by title-case normalization for both names. Refactor it without changing the output: define `clean_name(name)` so it returns the cleaned name, then replace both repeated cleanup expressions with calls to `clean_name`.","hint":"The finished program should still print the same two cleaned names; only the structure changes.","help":{"concept":"A refactor can preserve output while moving repeated logic into one reusable helper.","hint_1":"Define `clean_name(name)` once using `name.strip().title()`.","hint_2":"Use `clean_name(first)` and `clean_name(second)` instead of repeating the method chain."},"starterCode":"first = input()\nsecond = input()\n\nfirst_clean = first.strip().title()\nsecond_clean = second.strip().title()\n\nprint(first_clean)\nprint(second_clean)\n","solutionCode":"def clean_name(name):\n return name.strip().title()\n\nfirst = input()\nsecond = input()\n\nfirst_clean = clean_name(first)\nsecond_clean = clean_name(second)\n\nprint(first_clean)\nprint(second_clean)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `clean_name(...)` because that function call is explicitly required by the prompt."},"2":{"message":"Call `clean_name(...)` because that function call is explicitly required by the prompt."}}},"try-decomposition-and-refactoring-sketch1":{"title":"Extract word counting from the main flow","prompt":"This working program counts words directly in the main flow. Refactor it without changing its output: create `word_count(text)` that returns the number of words, then use that helper to compute `count`.","hint":"Move the split-and-count responsibility into `word_count(text)` and leave formatting in the main flow.","help":{"concept":"Decomposition can move one responsibility into a helper while the rest of the program keeps its original job.","hint_1":"Inside `word_count`, return `len(text.split())`.","hint_2":"Replace the inline counting lines with `count = word_count(text)`."},"starterCode":"text = input()\nwords = text.split()\ncount = len(words)\nprint(f\"Words: {count}\")\n","solutionCode":"def word_count(text):\n return len(text.split())\n\ntext = input()\ncount = word_count(text)\nprint(f\"Words: {count}\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `word_count(...)` because that function call is explicitly required by the prompt."}}},"try-decomposition-and-refactoring-sketch2":{"title":"Replace duplicated cleanup with a helper call","prompt":"`clean_name(name)` already owns the cleanup rule. `build_badge(name)` currently duplicates that rule. Refactor `build_badge` so it calls `clean_name(name)` and returns `\"Badge: \" + nice_name`. Keep the program's output unchanged.","hint":"The goal is not a new result; it is to make `build_badge` reuse the existing helper.","help":{"concept":"When one helper already owns a responsibility, another helper should call it instead of copying the same implementation.","hint_1":"Inside `build_badge`, assign `nice_name = clean_name(name)`.","hint_2":"Then return `\"Badge: \" + nice_name`."},"starterCode":"def clean_name(name):\n return name.strip().title()\n\ndef build_badge(name):\n nice_name = name.strip().title()\n return \"Badge: \" + nice_name\n\nname = input()\nprint(build_badge(name))\n","solutionCode":"def clean_name(name):\n return name.strip().title()\n\ndef build_badge(name):\n nice_name = clean_name(name)\n return \"Badge: \" + nice_name\n\nname = input()\nprint(build_badge(name))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"sc-refactor-goal":{"title":"What refactoring should preserve","prompt":"What is the main goal when refactoring code that already works?","hint":"The structure may improve, but the program should still do the same job for the same inputs.","help":{"concept":"Refactoring changes code structure without intentionally changing observable behavior.","hint_1":"Function names and line layout may change.","hint_2":"The same inputs should still produce the same intended results."},"options":{"a":"Improve the structure while preserving the program's behavior","b":"Change the output so the refactor is easy to notice","c":"Remove every function from the program","d":"Keep every original line in exactly the same place"}},"sc-extract-repetition":{"title":"Spot a helper candidate","prompt":"A program uses `name.strip().title()` in four different places. Which refactor best reduces that duplication?","hint":"Move the repeated transformation into one named operation.","help":{"concept":"Repeated logic is a strong candidate for a helper function.","hint_1":"The cleanup should have one definition.","hint_2":"Each old duplicate can then be replaced by a helper call."},"options":{"a":"Create `clean_name(name)` and call it from each place","b":"Copy the cleanup into four more places","c":"Rename all four variables but keep the duplicate cleanup","d":"Add extra print statements around each copy"}},"sc-one-responsibility":{"title":"Give a helper one clear job","prompt":"Which helper has the clearest single responsibility in a program that reads text, counts words, and formats a report?","hint":"A helper is easiest to understand when its name describes one focused task.","help":{"concept":"Decomposition separates distinct jobs so each function has a clear responsibility.","hint_1":"Counting words is one focused transformation.","hint_2":"Reading input, counting, formatting, and printing all at once mixes several responsibilities."},"options":{"a":"`word_count(text)` returns the number of words","b":"`do_everything()` reads input, counts, formats, and prints","c":"`stuff(x)` performs several unrelated actions","d":"`run()` duplicates the whole program twice"}},"sc-helper-reuse":{"title":"Reuse an existing helper","prompt":"`clean_name(name)` already returns a cleaned name. Inside `build_badge(name)`, which line best reuses that existing responsibility?","hint":"Call the helper instead of rewriting its `.strip().title()` logic.","help":{"concept":"Once a responsibility has a helper, other functions should call that helper instead of duplicating its implementation.","hint_1":"The helper call should receive `name`.","hint_2":"Store or use the value returned by `clean_name(name)`."},"options":{"a":"nice_name = clean_name(name)","b":"nice_name = name.strip().title()","c":"clean_name = name","d":"print = clean_name"}}},"tryIt":{"try_decomposition_and_refactoring_checkpoint":{"title":"Try it yourself","prompt":"Define `clean_title(text)` that strips spaces and title-cases the text. Print the cleaned version of `\" python helper \"`."},"try_decomposition_and_refactoring_sketch0":{"title":"Try it yourself","prompt":"This program already produces the correct output, but it repeats whitespace trimming followed by title-case normalization for both names. Refactor it without changing the output: define `clean_name(name)` so it returns the cleaned name, then replace both repeated cleanup expressions with calls to `clean_name`."},"try_decomposition_and_refactoring_sketch1":{"title":"Try it yourself","prompt":"Move one responsibility from the main flow into a helper without changing behavior."},"try_decomposition_and_refactoring_sketch2":{"title":"Try it yourself","prompt":"Replace duplicated helper logic with a call to the helper that already owns that responsibility."},"allowReveal":true}},"defining-and-calling-functions":{"label":"Defining and Calling Functions","summary":"Define reusable no-argument functions, call them after their definitions, and reuse a function by calling it more than once.","cards":{"sketch0":{"title":"Defining a function and calling it"},"sketch1":{"title":"Calling the same function more than once"},"sketch2":{"title":"Putting several statements inside a function"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-function-call":{"title":"Recognize a function call","prompt":"Which line calls a function named `greet`?","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"def greet():","b":"greet()","c":"print = greet","d":"return greet"}},"sc-parameter-meaning":{"title":"Understand a parameter","prompt":"In `def greet(name):`, what is `name`?","hint":"Reject any choice that changes the named values, branch order, or output.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"A printed message","b":"A parameter","c":"A return value","d":"A list"}},"mc-valid-calls":{"title":"Pick the valid function calls","prompt":"A function is defined as `def greet(name):`. Which calls are valid? Choose all correct answers.","hint":"The function expects exactly one argument.","help":{"concept":"When a function has one parameter, each call must provide one argument inside the parentheses.","hint_1":"Check how many values each call passes to `greet(...)`.","hint_2":"Valid calls have exactly one value between the parentheses, not zero and not two."},"options":{"a":"greet(\"Ava\")","b":"greet()","c":"greet(\"Ava\", \"Leo\")","d":"greet(\"Mina\")"}},"mc-return-uses":{"title":"Ways to use a returned value","prompt":"A function `double(x)` returns a number. Which lines use that returned value correctly? Choose all correct answers.","hint":"A returned value can be stored or printed.","help":{"concept":"When a function returns a value, you can place the call anywhere a normal value can be used, such as in an assignment or inside `print(...)`.","hint_1":"Look for lines where `double(4)` is treated like a value.","hint_2":"The correct lines either store the result in a variable or pass the result into another function like `print`."},"options":{"a":"result = double(4)","b":"print(double(4))","c":"return = double(4)","d":"def double(4):"}},"dr-define-then-call":{"title":"Order a simple function program","prompt":"Put these lines in the correct order to define a function and then call it.","hint":"The function must be defined before it is called.","help":{"concept":"Python reads code from top to bottom. A function definition comes first, its body stays indented under it, and the call comes after the definition.","hint_1":"Start with the `def` line, then place the indented body line under it.","hint_2":"After the two definition lines are together, put the function call last."},"tokens":{"t1":"def say_hi():","t2":"print(\"Hi\")","t3":"say_hi()"}},"dr-call-with-argument":{"title":"Order a function with one parameter","prompt":"Arrange the lines to define `show_name` and call it with `\"Ava\"`.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"def show_name(name):","t2":"print(name)","t3":"show_name(\"Ava\")"}},"fb-def-keyword":{"title":"Complete a function definition","prompt":"Choose the word that starts a function definition.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"[blank1] greet():","choices":["def","print","call","return"]},"fb-call-argument":{"title":"Fill in the argument","prompt":"Choose the value that completes the function call.","hint":"The function call should pass the name shown in quotes.","help":{"concept":"An argument is the value placed inside the parentheses when calling a function.","hint_1":"Look at the quotes already shown in the call.","hint_2":"The missing part is the exact text value between the parentheses, including the capital letter."},"template":"greet([blank1])","choices":["\"Ava\"","name","greet","print"]},"ci-make-greeting":{"title":"Write a greeting function","prompt":"Write `make_greeting(name)` so it returns a greeting string for that name.","hint":"Read the task \"Write a greeting function\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_greeting(name):\n # return a greeting string\n pass","solutionCode":"def make_greeting(name):\n return \"Hello, \" + name"},"ci-square-number":{"title":"Return the square","prompt":"Write `square(number)` so it returns the square of `number`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def square(number):\n # return the square of number\n pass","solutionCode":"def square(number):\n return number * number"},"ci-full-name":{"title":"Combine first and last name","prompt":"Write `full_name(first, last)` so it returns the first and last name joined into one string.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def full_name(first, last):\n # return the full name as one string\n pass","solutionCode":"def full_name(first, last):\n return first + \" \" + last"},"try-defining-and-calling-functions-checkpoint":{"title":"Define and call a function","prompt":"Define `say_hello()` so it prints `Hello from a function!`, then call it.","hint":"Put the `print()` inside the function body, then call the function below it.","help":{"concept":"A function groups statements that can be run by calling the function name.","hint_1":"Put the `print()` inside the function body, then call the function below it.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"# Define say_hello() below.\n\n","solutionCode":"def say_hello():\n print(\"Hello from a function!\")\n\nsay_hello()\n","sourceChecks":{"0":{"message":"Define a function named say_hello()."},"1":{"message":"Call say_hello() after defining it."}}},"try-defining-and-calling-functions-sketch0":{"title":"Define and call a message function","prompt":"Define a no-argument function named `show_message()`. Inside the function, print exactly `Functions are reusable!`. After the definition, call `show_message()` once.","hint":"Write the `def` line, indent the `print()` inside it, then place the call after the function body.","help":{"concept":"Defining the function creates the reusable block; calling the function is what makes its body run.","hint_1":"Your first line should be `def show_message():`.","hint_2":"After the indented print line, call `show_message()` with no arguments."},"starterCode":"# Define show_message() so its body prints: Functions are reusable!\n# Then call show_message() once.\n","solutionCode":"def show_message():\n print(\"Functions are reusable!\")\n\nshow_message()\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-defining-and-calling-functions-sketch1":{"title":"Call one function three times","prompt":"The starter already defines `ring_bell()` so one call prints `Ding!`. Below the definition, call `ring_bell()` exactly three times so the program prints three `Ding!` lines.","hint":"Do not copy the `print()` statement. Reuse the function by writing three calls.","help":{"concept":"A function can be reused by calling its name again instead of repeating the statements inside its body.","hint_1":"Leave the function definition unchanged.","hint_2":"Add three separate `ring_bell()` calls below the definition."},"starterCode":"def ring_bell():\n print(\"Ding!\")\n\n# Call ring_bell() exactly three times below.\n","solutionCode":"def ring_bell():\n print(\"Ding!\")\n\nring_bell()\nring_bell()\nring_bell()\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-defining-and-calling-functions-sketch2":{"title":"Put a loop inside a function","prompt":"Define a no-argument function named `show_colors()`. Inside it, create a list named `colors` containing `red`, `blue`, and `green` in that order, loop through `colors`, and print each color. After the definition, call `show_colors()` once.","hint":"The list and the `for` loop both belong inside the indented function body.","help":{"concept":"A function body can contain several statements, including list creation and loops you already know.","hint_1":"Indent both `colors = [...]` and the `for color in colors:` loop under `def show_colors():`.","hint_2":"After the function body ends, call `show_colors()` once."},"starterCode":"# Define show_colors().\n# Inside it, create colors = [\"red\", \"blue\", \"green\"].\n# Loop through colors and print each color.\n# Then call show_colors() once.\n","solutionCode":"def show_colors():\n colors = [\"red\", \"blue\", \"green\"]\n for color in colors:\n print(color)\n\nshow_colors()\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"sc-definition-vs-call":{"title":"Definition or call?","prompt":"Which line calls an already-defined function named `greet`?","hint":"A call uses the function name followed by parentheses, without the `def` keyword.","help":{"concept":"A function definition creates the named block of code; a function call runs that block.","hint_1":"`def greet():` starts the definition.","hint_2":"To run the function later, write `greet()`."},"options":{"a":"def greet():","b":"greet()","c":"print = greet","d":"return greet"}},"sc-function-body-indent":{"title":"Identify the function body","prompt":"Which line correctly belongs inside the body of `def show_message():`?","hint":"Statements inside a function body are indented under the `def` line.","help":{"concept":"Indentation tells Python which statements belong to the function body.","hint_1":"The body line must be indented.","hint_2":"The call itself belongs after the definition, not inside its body."},"options":{"a":" print(\"Ready\")","b":"def print(\"Ready\")","c":"show_message():","d":"return = \"Ready\""}},"sc-call-count":{"title":"Count function calls","prompt":"A function `ping()` prints `Ping` once. If the program contains `ping()` on two separate lines, how many times is `Ping` printed?","hint":"Each function call runs the function body once.","help":{"concept":"Calling the same function repeatedly reuses the same body each time.","hint_1":"The first call runs the print once.","hint_2":"The second call runs that same print once again."},"options":{"a":"Two times","b":"One time","c":"Zero times","d":"The function can only be called once"}},"sc-define-before-call":{"title":"Place the call after the definition","prompt":"Which program order correctly defines `cheer()` before trying to call it?","hint":"Python runs top-level statements from top to bottom.","help":{"concept":"The function name must already be defined by the time Python reaches the call.","hint_1":"Put the `def cheer():` block first.","hint_2":"Place `cheer()` after the indented function body."},"options":{"a":"define `cheer()`, then call `cheer()`","b":"call `cheer()`, then define `cheer()`","c":"call `cheer()` without defining it","d":"put the call before the indented body"}}},"tryIt":{"try_defining_and_calling_functions_checkpoint":{"title":"Try it yourself","prompt":"Define `say_hello()` so it prints `Hello from a function!`, then call it."},"try_defining_and_calling_functions_sketch0":{"title":"Try it yourself","prompt":"Define a no-argument function, put its work in the indented body, and call it once."},"try_defining_and_calling_functions_sketch1":{"title":"Try it yourself","prompt":"Reuse one already-defined function by calling it exactly three times."},"try_defining_and_calling_functions_sketch2":{"title":"Try it yourself","prompt":"Define a no-argument function named `show_colors()`. Inside it, create a list named `colors` containing `red`, `blue`, and `green` in that order, loop through `colors`, and print each color. After the definition, call `show_colors()` once."},"allowReveal":true}},"docstrings-and-function-contracts":{"label":"Docstrings and Function Contracts","summary":"Write real function docstrings as the first statement in a function, use them to describe inputs and returned results, and keep implementation behavior consistent with the documented contract.","cards":{"sketch0":{"title":"A docstring is the function's first statement"},"sketch1":{"title":"A contract explains inputs and returned results"},"sketch2":{"title":"The implementation must match the contract"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-docstring-location":{"title":"Where a docstring goes","prompt":"Where should a function's docstring be placed?","hint":"Look for the string that appears immediately inside the function.","help":{"concept":"A function docstring is the first string literal inside the function body, directly under the `def` line.","hint_1":"It is not placed before the function definition or after the return statement.","hint_2":"Choose the option where the triple-quoted string comes right after `def ...:`."},"options":{"a":"Directly under the function definition as the first statement","b":"Inside the parameter list","c":"After the return statement","d":"Only at the end of the program"}},"sc-contract-purpose":{"title":"What a function contract explains","prompt":"What is the main purpose of a function contract?","hint":"Think about inputs and outputs.","help":{"concept":"A function contract tells other programmers what values a function expects and what result or behavior it provides.","hint_1":"A contract is about how to use the function correctly, not about changing Python syntax.","hint_2":"Pick the option that mentions expected arguments and returned result."},"options":{"a":"It explains what inputs the function expects and what it returns","b":"It automatically fixes bugs in the function","c":"It makes the function run faster","d":"It replaces the need for function names"}},"mc-good-docstring-features":{"title":"Features of a helpful docstring","prompt":"Which statements describe a helpful function docstring? Choose all that apply.","hint":"Look for statements that make the function easier to use correctly.","help":{"concept":"Helpful docstrings are specific, match the code, and explain the function's behavior clearly enough for someone to call it correctly.","hint_1":"Good docstrings usually mention what the function returns or does with its inputs.","hint_2":"Select the choices that are clear and accurate, not vague or unrelated."},"options":{"a":"It clearly says what the function returns or does","b":"It matches the actual behavior of the code","c":"It should be as vague as possible so it works for any function","d":"It can mention important input expectations"}},"mc-return-vs-print-contract":{"title":"Return vs print in a contract","prompt":"A docstring says a function returns a value. Which code patterns fit that contract? Choose all that apply.","hint":"Look for functions that send a value back to the caller.","help":{"concept":"When a contract says a function returns a value, the function should use `return` so the caller can store or reuse the result.","hint_1":"Printing shows output, but it does not give the caller a reusable value.","hint_2":"Choose the options that use `return` to produce the result."},"options":{"a":"`return a + b`","b":"`return name.upper()`","c":"`print(a + b)`","d":"`print(\"Done\")`"}},"dr-docstring-order":{"title":"Order of a documented function","prompt":"Put these parts in the correct order for a simple documented function.","hint":"Start with the function header, then the docstring, then the body.","help":{"concept":"A documented function is written in a standard order: definition line first, docstring next, then the executable code.","hint_1":"The docstring belongs inside the function, not before the `def` line.","hint_2":"After the docstring, place the statement that computes or returns the result."},"tokens":{"t1":"`def double(number):`","t2":"`\"\"\"Return twice number.\"\"\"`","t3":"`return number * 2`"}},"dr-contract-reading":{"title":"Read a function contract in order","prompt":"Arrange these ideas in a sensible order for understanding a function contract.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"Inputs the function expects","t2":"What the function does","t3":"Value the function returns"}},"fb-return-word":{"title":"Complete the docstring wording","prompt":"Choose the word that best completes the docstring.","hint":"The sentence describes giving a value back to the caller.","help":{"concept":"A docstring should describe the value sent back to the caller when the function does not merely print.","hint_1":"Choose the verb used in function documentation for a value sent back to the caller.","hint_2":"Pick the choice that means the function gives a result back to the caller."},"template":"`\"\"\"[blank1] the sum of two numbers.\"\"\"`","choices":["Return","Print","Loop through","Import"]},"fb-docstring-position":{"title":"Complete the function example","prompt":"Choose the line that correctly fills the blank.","hint":"The missing line should be the docstring, not code that runs the calculation.","help":{"concept":"The docstring is a descriptive string placed as the first statement inside the function body.","hint_1":"The blank comes right after the function header.","hint_2":"Choose the triple-quoted string that describes the function's result."},"template":"```python\ndef square(number):\n [blank1]\n return number * number\n```","choices":["`\"\"\"Return the square of number.\"\"\"`","`print(number * number)`","`number * number`","`square(number)`"]},"ci-add-docstring":{"title":"Add a matching docstring","prompt":"Add a docstring under `make_lower(text)` that clearly says what the function returns.","hint":"Read the task \"Add a matching docstring\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_lower(text):\n # Add a docstring below.\n return text.lower()","solutionCode":"def make_lower(text):\n \"\"\"Return the lowercase version of text.\"\"\"\n return text.lower()"},"ci-write-contract-function":{"title":"Write a documented function with a clear contract","prompt":"Write `repeat_word(word, times)` so it returns the repeated text, and add a docstring that explains that contract clearly.","hint":"Read the task \"Write a documented function with a clear contract\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def repeat_word(word, times):\n # Add a docstring and return the repeated word.\n pass","solutionCode":"def repeat_word(word, times):\n \"\"\"Return word repeated times times.\"\"\"\n return word * times"},"ci-fix-print-vs-return":{"title":"Fix the contract mismatch","prompt":"The docstring says `total_price(price, tax)` should return the total, but the starter code prints it instead. Fix the function so its behavior matches the docstring.","hint":"Read the task \"Fix the contract mismatch\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def total_price(price, tax):\n \"\"\"Return the total of price and tax.\"\"\"\n print(price + tax)","solutionCode":"def total_price(price, tax):\n \"\"\"Return the total of price and tax.\"\"\"\n return price + tax"},"try-docstrings-and-function-contracts-checkpoint":{"title":"Write a documented helper","prompt":"Define `square(number)` with a docstring and return the square of the number. Print `square(5)`.","hint":"Place a triple-quoted string as the first line inside the function.","help":{"concept":"A docstring describes the function contract for readers and tools.","hint_1":"Place a triple-quoted string as the first line inside the function.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def square(number):\n # Add a docstring and return the square.\n pass\n\nprint(square(5))\n","solutionCode":"def square(number):\n \"\"\"Return number multiplied by itself.\"\"\"\n return number * number\n\nprint(square(5))\n"},"try-docstrings-and-function-contracts-sketch0":{"title":"Add a real docstring to a working function","prompt":"The function already works. Add the docstring `\"\"\"Return text stripped and title-cased.\"\"\"` as the first statement inside `normalize_city(text)`. Do not change the function's behavior.","hint":"Place the triple-quoted string directly under `def normalize_city(text):`, before the return statement.","help":{"concept":"A real function docstring is the first string literal in the function body.","hint_1":"Do not turn the requested docstring into a `#` comment.","hint_2":"Keep the existing `return text.strip().title()` behavior unchanged."},"starterCode":"def normalize_city(text):\n return text.strip().title()\n\ncity = input()\nprint(normalize_city(city))\n","solutionCode":"def normalize_city(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n\ncity = input()\nprint(normalize_city(city))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-docstrings-and-function-contracts-sketch1":{"title":"Fix code that breaks its return contract","prompt":"`total_price(price, tax)` already has the contract `\"\"\"Return price plus tax.\"\"\"`, but the implementation prints the total instead of returning it. Fix the function so the caller receives the value. Keep the existing docstring.","hint":"Replace the display-only behavior inside the function with a return statement.","help":{"concept":"If a contract promises a returned value, the implementation must give that value back to the caller.","hint_1":"Inside the function, use `return price + tax`.","hint_2":"Do not replace or remove the existing docstring."},"starterCode":"def total_price(price, tax):\n \"\"\"Return price plus tax.\"\"\"\n print(price + tax)\n\nprice = int(input())\ntax = int(input())\nresult = total_price(price, tax)\nprint(result)\n","solutionCode":"def total_price(price, tax):\n \"\"\"Return price plus tax.\"\"\"\n return price + tax\n\nprice = int(input())\ntax = int(input())\nresult = total_price(price, tax)\nprint(result)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-docstrings-and-function-contracts-sketch2":{"title":"Implement a function from its contract","prompt":"`is_passing(score)` already documents its contract: `\"\"\"Return True when score is 70 or higher.\"\"\"`. Complete the function so its returned Boolean value matches that contract for every score.","hint":"The phrase '70 or higher' translates to a greater-than-or-equal comparison.","help":{"concept":"A contract can be read as a precise requirement for the implementation.","hint_1":"Return a Boolean expression rather than printing a message.","hint_2":"Use `return score >= 70` so 70 itself is included."},"starterCode":"def is_passing(score):\n \"\"\"Return True when score is 70 or higher.\"\"\"\n pass\n\nscore = int(input())\nprint(is_passing(score))\n","solutionCode":"def is_passing(score):\n \"\"\"Return True when score is 70 or higher.\"\"\"\n return score >= 70\n\nscore = int(input())\nprint(is_passing(score))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"sc-real-docstring":{"title":"Identify a real function docstring","prompt":"Which placement makes a string the docstring for `clean(text)`?","hint":"Python recognizes the first string literal in the function body as its docstring.","help":{"concept":"A function docstring is a string literal used as the first statement inside that function.","hint_1":"A comment does not become the function's docstring.","hint_2":"The triple-quoted string belongs directly under the `def` line, before executable statements."},"options":{"a":"def clean(text):\n \"\"\"Return cleaned text.\"\"\"\n return text.strip()","b":"\"\"\"Return cleaned text.\"\"\"\ndef clean(text):\n return text.strip()","c":"def clean(text):\n return text.strip()\n \"\"\"Return cleaned text.\"\"\"","d":"def clean(text):\n # \"\"\"Return cleaned text.\"\"\"\n return text.strip()"}},"sc-contract-content":{"title":"What a useful contract explains","prompt":"Which docstring most clearly describes the contract of `double(number)`?","hint":"A useful beginner contract says what input the function works with and what result comes back.","help":{"concept":"A clear contract describes the function's expected input and the result or behavior it provides.","hint_1":"Avoid vague wording such as 'Do something with a number.'","hint_2":"The best choice states that the function returns twice the given number."},"options":{"a":"\"\"\"Return twice the given number.\"\"\"","b":"\"\"\"Do something.\"\"\"","c":"\"\"\"This is Python code.\"\"\"","d":"\"\"\"Print anything eventually.\"\"\""}},"sc-contract-match":{"title":"Match code to the contract","prompt":"The docstring says `\"\"\"Return the uppercase version of text.\"\"\"`. Which function body matches that contract?","hint":"The caller must receive the uppercase string as a value.","help":{"concept":"Documentation is useful only when it agrees with the implementation.","hint_1":"The contract says `Return`, so printing alone is not enough.","hint_2":"Return `text.upper()`."},"options":{"a":"return text.upper()","b":"print(text.upper())","c":"input(text.upper())","d":"text = \"upper\""}},"sc-read-contract":{"title":"Implement from a stated contract","prompt":"A function's docstring says `\"\"\"Return True when score is 70 or higher.\"\"\"`. Which expression should the function return?","hint":"Translate the documented condition directly into a Boolean expression.","help":{"concept":"A contract can guide implementation by stating exactly what result is expected.","hint_1":"The boundary value 70 should count as True.","hint_2":"Use a greater-than-or-equal comparison."},"options":{"a":"score >= 70","b":"score > 70","c":"score == 70","d":"print(score)"}}},"tryIt":{"try_docstrings_and_function_contracts_checkpoint":{"title":"Try it yourself","prompt":"Define `square(number)` with a docstring and return the square of the number. Print `square(5)`."},"try_docstrings_and_function_contracts_sketch0":{"title":"Try it yourself","prompt":"Add a real function docstring without changing already-correct behavior."},"try_docstrings_and_function_contracts_sketch1":{"title":"Try it yourself","prompt":"Fix an implementation that prints even though its documented contract promises a returned value."},"try_docstrings_and_function_contracts_sketch2":{"title":"Try it yourself","prompt":"Read an existing function contract and implement the exact behavior it describes."},"allowReveal":true}},"module-6-name-badge-package":{"label":"Module Project: Build a Name Badge App","summary":"Refactor a working single-file badge program into focused sibling modules, document the helper contracts, and connect the returned values into one polished welcome message.","cards":{"sketch0":{"title":"Start from one working badge program"},"project":{"title":"Name Badge App"}},"projectSteps":{"mp_1":{"title":"Move name cleanup into names.py"},"mp_2":{"title":"Move badge formatting into badges.py"},"mp_3":{"title":"Document and refine the helper contracts"},"mp_4":{"title":"Add the final welcome-message helper"}},"quiz":{"mp-1-create-clean-name-module":{"title":"Create the name cleaner module","prompt":"Start the badge app by moving name cleanup into its own helper file. Create `tools/names.py` with `clean_name(text)`, import it in `main.py`, read one name from input, and print the cleaned result.","hint":"Put the reusable cleaning logic in `tools/names.py`, then let `main.py` call it.","help":{"concept":"A helper module keeps reusable logic out of `main.py`, which makes the badge app easier to grow.","hint_1":"In `tools/names.py`, define `clean_name(text)` and return `text.strip().title()`.","hint_2":"In `main.py`, import `clean_name`, read input, and print the cleaned name."},"starterCode":"raw_name = input()\n\n# Start the badge app by moving name cleanup into tools/names.py.\n# Import clean_name, then print the cleaned version of raw_name.\n","solutionFiles":{"main_py":{"content":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Import from tools.names."},"1":{"message":"Define clean_name(text) inside tools/names.py."},"2":{"message":"clean_name should strip whitespace."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"mp-2-add-badge-helper":{"title":"Add the badge helper module","prompt":"Keep the working `clean_name` helper from the last step. Now add `tools/badges.py` with `make_badge(name, role)`, import it in `main.py`, read a role too, and print the finished badge.","hint":"Leave `tools/names.py` working, add one new helper file, then connect it in `main.py`.","help":{"concept":"This step adds a second helper file so each module has one clear job: names clean names, badges format badge text.","hint_1":"Create `tools/badges.py` with `make_badge(name, role)`.","hint_2":"In `main.py`, clean the name first, then pass `name` and `role` into `make_badge(...)`."},"starterCode":"from tools.names import clean_name\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\n\n# Keep the name cleaner working, then add tools.badges.\n# Import make_badge and print the finished badge for this cleaned name and role.\n","starterFiles":{"tools_init_py":{"content":""},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"# Add make_badge(name, role) here.\n# Return one formatted string for the badge.\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Import from tools.badges."},"1":{"message":"Define make_badge in tools/badges.py."},"2":{"message":"make_badge should uppercase the role."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"mp-3-document-badge-helper":{"title":"Document and clean the badge helper","prompt":"Start from the working two-helper badge app. Keep the output the same, but improve `tools/badges.py` by adding a docstring and cleaning the role before uppercasing it.","hint":"This step refines the helper in place instead of changing the overall app flow.","help":{"concept":"Small helper functions are easier to maintain when they explain themselves and handle messy input cleanly.","hint_1":"Add a triple-quoted docstring under `def make_badge(name, role):`.","hint_2":"Store `role.strip().upper()` in a variable before returning the badge text."},"starterCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n\n# Keep this badge flow working.\n# Add the next improvement inside tools/badges.py.\n","starterFiles":{"tools_init_py":{"content":""},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n # Add a docstring that explains what this helper returns.\n # Then clean role before uppercasing it so extra spaces do not reach the badge.\n return f\"{role.upper()} badge: {name}\"\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return a formatted badge label for a cleaned name and role.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Add a docstring to make_badge in tools/badges.py."},"1":{"message":"Clean the role before uppercasing it."},"2":{"message":"Uppercase the role in make_badge."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"mp-4-package-welcome-message":{"title":"Print the final welcome badge","prompt":"Start from the documented badge app. Keep both helpers, store the badge in a variable, and replace the direct badge print with one friendly final line that begins with `Welcome!`.","hint":"Reuse the existing helper flow, but make the final output feel like a polished handoff.","help":{"concept":"The final app uses small helper modules to make the main program read like a simple story: get input, clean it, build the badge, print the welcome message.","hint_1":"Use `badge = make_badge(name, role)` after cleaning the name.","hint_2":"Print one line that starts with `Welcome!` and includes the badge text."},"starterCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n\n# Replace the line above with one polished welcome message.\n# Store the badge in a variable, then print a line that starts with Welcome!.\n","starterFiles":{"tools_init_py":{"content":""},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return a formatted badge label for a cleaned name and role.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(f\"Welcome! {badge}\")\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return a formatted badge label for a cleaned name and role.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Build the badge with make_badge() instead of hard-coding the final text."},"1":{"message":"Print the final welcome message."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(f\"Welcome! {badge}\")\n"},"try-module-6-name-badge-package-sketch0":{"title":"Complete the single-file badge starting point","prompt":"Complete `clean_name(text)` so the starting badge program works in one file. Return the name with surrounding spaces removed and title-cased. Do not move functions into helper files yet—the project steps will refactor this working version.","hint":"Return `text.strip().title()` from `clean_name`.","help":{"concept":"The project begins with working single-file behavior so later steps can focus on refactoring structure without losing correctness.","hint_1":"Replace `pass` with `return text.strip().title()`.","hint_2":"Keep `make_badge`, input handling, and the final print unchanged."},"starterCode":"def clean_name(text):\n # Return text stripped and title-cased.\n pass\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Define clean_name in tools/names.py."},"2":{"message":"clean_name should strip spaces."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"def clean_name(text):\n # Return text stripped and title-cased.\n pass\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"}}},"mp-1-move-name-helper":{"title":"Move name cleanup into names.py","prompt":"Start from the working single-file badge program. Refactor it without changing the output: move `clean_name(text)` into a new sibling file named `names.py`, then import it in `main.py` with a from-import that brings `clean_name` in from the `names` module. Keep `make_badge` in `main.py` for this step.","hint":"Only the name-cleaning responsibility moves in this step.","help":{"concept":"A refactor can move one helper into its own module while preserving the app's existing behavior.","hint_1":"Create `names.py` with the existing `clean_name(text)` function.","hint_2":"Remove that function definition from `main.py` and import it from `names`."},"starterCode":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"}},"solutionCode":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `clean_name` from `names`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"mp-2-move-badge-helper":{"title":"Move badge formatting into badges.py","prompt":"Continue from the previous exact project state. Move `make_badge(name, role)` out of `main.py` into a new sibling file `badges.py`, import it with a from-import that brings `make_badge` in from the `badges` module, and keep the same badge output.","hint":"After this step, `main.py` should coordinate the two imported helpers instead of defining either one.","help":{"concept":"Different sibling modules can own different responsibilities while `main.py` connects their returned values.","hint_1":"Create `badges.py` and move the existing `make_badge` behavior there.","hint_2":"Import both `clean_name` and `make_badge` in `main.py`."},"starterCode":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.strip().upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `make_badge` from `badges`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Call `make_badge(...)` because that function call is explicitly required by the prompt."}}},"mp-3-document-helper-contracts":{"title":"Document and refine the helper contracts","prompt":"Keep the two-module badge app behavior unchanged. Add the exact docstring `\"\"\"Return text stripped and title-cased.\"\"\"` as the first statement in `clean_name`. Add the exact docstring `\"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"` as the first statement in `make_badge`. In `make_badge`, store `role.strip().upper()` in local variable `clean_role` before returning the badge.","hint":"This step changes documentation and internal structure, not the app's output.","help":{"concept":"A documented helper should have a real function docstring that matches its behavior, and local variables can make intermediate work clearer.","hint_1":"Put each requested triple-quoted string directly under its `def` line.","hint_2":"In `badges.py`, create `clean_role = role.strip().upper()` and build the returned badge from `clean_role`."},"starterCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.strip().upper()} badge: {name}\"\n"}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Use `upper()` because that method is explicitly required by the prompt."}}},"mp-4-add-welcome-helper":{"title":"Add the final welcome-message helper","prompt":"Continue from the documented two-helper app. Create a sibling module `messages.py` with `welcome_message(badge)`. Give it the docstring `\"\"\"Return a welcome message containing the badge.\"\"\"` and return `\"Welcome! \" + badge`. Import it in `main.py` and print the returned welcome message.","hint":"The new helper owns only the final message; keep name cleanup and badge formatting in their existing modules.","help":{"concept":"The finished app decomposes three responsibilities across three small sibling modules while `main.py` coordinates their returned values.","hint_1":"Create `messages.py` with a documented `welcome_message(badge)` function.","hint_2":"Import it with `from messages import welcome_message` and print `welcome_message(badge)`."},"starterCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\nfrom messages import welcome_message\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(welcome_message(badge))\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\nfrom messages import welcome_message\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(welcome_message(badge))\n"},"names_py":{"content":"def clean_name(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"},"messages_py":{"content":"def welcome_message(badge):\n \"\"\"Return a welcome message containing the badge.\"\"\"\n return \"Welcome! \" + badge\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}}},"tryIt":{"try_module_6_name_badge_package_sketch0":{"title":"Try it yourself","prompt":"Complete the working single-file badge baseline that the project will refactor."},"allowReveal":true}},"parameters-and-return-values":{"label":"Parameters and Return Values","summary":"Use parameters to receive argument values, pass multiple arguments in the correct order, and return results that the caller can store or use.","cards":{"sketch0":{"title":"Parameters receive argument values"},"sketch1":{"title":"Functions can receive more than one parameter"},"quiz":{"title":"Check your understanding"},"sketch2":{"title":"Return sends a result back to the caller"}},"quiz":{"sc-parameter-role":{"title":"What a parameter does","prompt":"In `def greet(name):`, what is `name`?","hint":"Look at the value that gets passed into the function call.","help":{"concept":"A parameter is a variable in a function definition that receives a value when the function is called.","hint_1":"`name` appears inside the parentheses of the function definition, so it is part of the function's input.","hint_2":"Ask which choice describes a placeholder that gets its value from a call like `greet(\"Ava\")`."},"options":{"a":"A parameter that receives an argument value","b":"A printed output line","c":"A list method","d":"A return statement"}},"sc-return-purpose":{"title":"Why use return","prompt":"What does `return` do in a Python function?","hint":"Think about how a function sends a result back to the code that called it.","help":{"concept":"The `return` statement ends the function call and gives a value back to the caller.","hint_1":"Unlike `print`, `return` does not mainly display text in the output panel.","hint_2":"Choose the option about sending a result out of the function so it can be stored or used later."},"options":{"a":"It repeats the function automatically","b":"It sends a value back to the caller","c":"It creates a new parameter","d":"It renames the function"}},"mc-return-uses":{"title":"Ways to use a returned value","prompt":"Which statements correctly use a function's returned value? Choose all that apply.","hint":"A returned value can be stored, printed, or used inside another expression.","help":{"concept":"Returned values behave like regular values, so they can be assigned, printed, or combined in expressions.","hint_1":"Look for lines where the function call appears where a normal value could appear.","hint_2":"A function call that returns a number can go on the right side of `=` or inside `print(...)`."},"options":{"a":"`total = add(2, 3)`","b":"`print(add(2, 3))`","c":"`return = add(2, 3)`","d":"`def add = (2, 3)`"}},"mc-print-vs-return":{"title":"Print versus return","prompt":"Which statements about `print` and `return` are true? Choose all that apply.","hint":"One shows output now, and the other gives a value back to the caller.","help":{"concept":"`print` displays text in the output panel, while `return` passes a value back from the function.","hint_1":"Think about whether the result can be reused later in another variable or expression.","hint_2":"Choose the statements that match these roles: visible output for `print`, reusable result for `return`."},"options":{"a":"`print` sends visible text to the output panel","b":"`return` can give a result back to the caller","c":"`print` and `return` always do exactly the same job","d":"`return` can only be used outside functions"}},"dr-function-flow":{"title":"Order of a function call","prompt":"Put these steps in the correct order for what happens when a function with parameters is called.","hint":"Start with the call, then think about values entering the function and a result coming back.","help":{"concept":"A function call follows a sequence: call the function, pass arguments into parameters, run the body, then return a result.","hint_1":"The function body cannot run until the arguments have been matched to the parameters.","hint_2":"The returned value comes after the body finishes its calculation."},"tokens":{"t1":"Call the function with argument values","t2":"Those values are assigned to the parameters","t3":"The function body runs using those parameter values","t4":"The function returns a result to the caller"}},"dr-build-function":{"title":"Build a simple return function","prompt":"Arrange these lines to make a function that takes one parameter and returns double the value.","hint":"The function header comes first, then the return line, then the call that uses the result.","help":{"concept":"A basic function definition needs a header, an indented body, and then any code that calls the function.","hint_1":"The `return` line must be inside the function, so it belongs directly under the `def` line.","hint_2":"The line that prints the result should come after the function has been defined."},"tokens":{"t1":"def double(number):","t2":"return number * 2","t3":"result = double(5)","t4":"print(result)"}},"fb-call-argument":{"title":"Fill the argument","prompt":"Complete the function call so the function receives the number 7.","hint":"The blank is the value being passed into the function call.","help":{"concept":"An argument is the actual value you place inside the parentheses when calling a function.","hint_1":"The function name is already written, so the missing part is the value inside the parentheses.","hint_2":"Choose the number that would be passed into `show_score` as its input."},"template":"show_score([blank1])","choices":["show_score","7","return"]},"fb-return-expression":{"title":"Complete the return line","prompt":"Choose the expression that makes the function return the sum of `price` and `tax`.","hint":"The blank should be the value expression after `return`.","help":{"concept":"A return statement can send back the result of an expression, such as adding two parameters together.","hint_1":"Both `price` and `tax` are already available as parameter names in the function.","hint_2":"Pick the choice that adds the two parameter values instead of naming a keyword or only one variable."},"template":"return [blank1]","choices":["price + tax","def","price"]},"ci-make-label":{"title":"Return a label string","prompt":"Write `make_label(item, count)` so it returns a label string like `Apples: 3`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_label(item, count):\n # return a string like \"Apples: 3\"\n pass","solutionCode":"def make_label(item, count):\n return item + \": \" + str(count)"},"ci-calculate-tip":{"title":"Return a tip amount","prompt":"Write `calculate_tip(bill, percent)` so it returns just the tip amount for that bill and percent.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def calculate_tip(bill, percent):\n # return the tip amount\n pass","solutionCode":"def calculate_tip(bill, percent):\n return bill * percent / 100"},"ci-first-item":{"title":"Return the first list item","prompt":"Write `first_item(items)` so it returns the first element from the list.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def first_item(items):\n # return the first element from the list\n pass","solutionCode":"def first_item(items):\n return items[0]"},"try-parameters-and-return-values-checkpoint":{"title":"Return a doubled number","prompt":"Define `double(number)` so it returns twice the input. Print `double(7)`.","hint":"Use `return number * 2`.","help":{"concept":"A return value sends a result back to the caller.","hint_1":"Use `return number * 2`.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def double(number):\n # Return twice the number.\n pass\n\nprint(double(7))\n","solutionCode":"def double(number):\n return number * 2\n\nprint(double(7))\n"},"try-parameters-and-return-values-sketch0":{"title":"Reuse one parameter with different arguments","prompt":"Complete `make_badge(name)` so it returns `Badge: ` followed by `name`. The program reads two names. Keep the two calls so the same function produces one badge for each input name.","hint":"The parameter `name` receives a different argument on each call.","help":{"concept":"One parameter lets the same function body work with different argument values.","hint_1":"Inside the function, return `\"Badge: \" + name`.","hint_2":"Leave the calls `make_badge(name1)` and `make_badge(name2)` in place."},"starterCode":"def make_badge(name):\n # Return \"Badge: \" followed by name.\n pass\n\nname1 = input()\nname2 = input()\nprint(make_badge(name1))\nprint(make_badge(name2))\n","solutionCode":"def make_badge(name):\n return \"Badge: \" + name\n\nname1 = input()\nname2 = input()\nprint(make_badge(name1))\nprint(make_badge(name2))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `make_badge(...)` because that function call is explicitly required by the prompt."}}},"try-parameters-and-return-values-sketch1":{"title":"Use two parameters in order","prompt":"Complete `difference(high, low)` so it returns `high - low`. The program reads two integers and prints the value returned by `difference(high, low)`.","hint":"The first argument becomes `high`; the second becomes `low`.","help":{"concept":"With multiple positional parameters, argument order determines which value each parameter receives.","hint_1":"Return `high - low` inside the function.","hint_2":"Keep the call in the same order: `difference(high, low)`."},"starterCode":"def difference(high, low):\n # Return high minus low.\n pass\n\nhigh = int(input())\nlow = int(input())\nprint(difference(high, low))\n","solutionCode":"def difference(high, low):\n return high - low\n\nhigh = int(input())\nlow = int(input())\nprint(difference(high, low))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `difference(...)` because that function call is explicitly required by the prompt."}}},"sc-parameter-vs-argument":{"title":"Parameter versus argument","prompt":"Given `def greet(name):` and the call `greet(\"Ava\")`, which statement is correct?","hint":"Look separately at the function definition and the function call.","help":{"concept":"A parameter is the variable named in the definition; an argument is the actual value supplied by a call.","hint_1":"`name` is written in `def greet(name):`, so it is the parameter.","hint_2":"`\"Ava\"` is supplied by `greet(\"Ava\")`, so it is the argument."},"options":{"a":"`name` is the parameter and `\"Ava\"` is the argument","b":"`\"Ava\"` is the parameter and `name` is the argument","c":"Both are return values","d":"Neither one provides input to the function"}},"sc-argument-order":{"title":"Match arguments to parameters","prompt":"Given `def subtract(first, second): return first - second`, what does `subtract(10, 3)` return?","hint":"The first argument goes into `first`; the second argument goes into `second`.","help":{"concept":"Positional arguments are matched to parameters from left to right.","hint_1":"For this call, `first` becomes `10`.","hint_2":"`second` becomes `3`, so evaluate `10 - 3`."},"options":{"a":"7","b":"-7","c":"13","d":"3"}},"sc-valid-two-argument-call":{"title":"Call a two-parameter function","prompt":"A function is defined as `def show_pair(left, right):`. Which call supplies both required arguments?","hint":"There are two parameters, so the call needs two argument values.","help":{"concept":"A normal call must supply the required number of positional arguments.","hint_1":"Look for two comma-separated values inside the parentheses.","hint_2":"The function name in the call must still be `show_pair`."},"options":{"a":"show_pair()","b":"show_pair(\"A\")","c":"show_pair(\"A\", \"B\")","d":"def show_pair(\"A\", \"B\")"}},"sc-returned-value":{"title":"Use a returned value","prompt":"If `double(5)` returns `10`, what value is stored by `result = double(5)`?","hint":"The returned value replaces the function call in the assignment.","help":{"concept":"A returned value can be assigned to a variable just like another computed value.","hint_1":"`double(5)` produces the value `10`.","hint_2":"That value is assigned to `result`."},"options":{"a":"5","b":"10","c":"double","d":"Nothing is stored"}},"try-parameters-and-return-values-sketch2":{"title":"Store a returned result","prompt":"Complete `rectangle_area(width, height)` so it returns `width * height`. Then keep the caller code that stores the returned value in `area` and prints `area`.","hint":"The function should return the calculation; the assignment outside the function stores that returned value.","help":{"concept":"A return value travels back to the call site, where it can be assigned to a variable and used later.","hint_1":"Inside the function, write `return width * height`.","hint_2":"Outside the function, `area = rectangle_area(width, height)` stores the returned number."},"starterCode":"def rectangle_area(width, height):\n # Return the rectangle's area.\n pass\n\nwidth = int(input())\nheight = int(input())\narea = rectangle_area(width, height)\nprint(area)\n","solutionCode":"def rectangle_area(width, height):\n return width * height\n\nwidth = int(input())\nheight = int(input())\narea = rectangle_area(width, height)\nprint(area)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `rectangle_area(...)` because that function call is explicitly required by the prompt."}}}},"tryIt":{"try_parameters_and_return_values_checkpoint":{"title":"Try it yourself","prompt":"Define `double(number)` so it returns twice the input. Print `double(7)`."},"try_parameters_and_return_values_sketch0":{"title":"Try it yourself","prompt":"Use one parameter with two different argument values and return a result for each call."},"try_parameters_and_return_values_sketch1":{"title":"Try it yourself","prompt":"Use two parameters in order and return a calculation based on both values."},"allowReveal":true,"try_parameters_and_return_values_sketch2":{"title":"Try it yourself","prompt":"Return a computed result and store that returned value in a caller-side variable."}}},"print-vs-return":{"label":"Print vs Return","summary":"Distinguish display-only functions from functions that return reusable data, understand why printing a print-only call shows `None`, and fix code that prints when the caller needs a value.","cards":{"sketch0":{"title":"Printing displays a value but returns None"},"sketch1":{"title":"Returned values can be stored and reused"},"sketch2":{"title":"Fix a function that prints when it should return"},"quiz":{"title":"Check your understanding"}},"quiz":{"pvrs-sc-1":{"title":"Which statement describes return?","prompt":"Which statement best describes what `return` does in a function?","hint":"Think about whether the value is only shown or sent back to the code that called the function.","help":{"concept":"`return` gives a result back to the caller so it can be stored, reused, or combined with other values.","hint_1":"A returned value can be assigned to a variable like `result = my_function()`.","hint_2":"Look for the option about sending a value back from the function, not just displaying it."},"options":{"a":"It sends a value back from the function to the caller.","b":"It always prints a value in the output panel.","c":"It repeats the function from the beginning.","d":"It creates a new parameter automatically."}},"pvrs-sc-2":{"title":"Which function result can be reused?","prompt":"A function should calculate a number and let later code multiply that number by 10. Which approach is best?","hint":"The later code needs the function's result as a value, not just visible output.","help":{"concept":"When later code must keep using a result, the function should return that result instead of only printing it.","hint_1":"If the function only prints, another expression cannot directly use that printed value in a calculation.","hint_2":"Choose the option where the function gives the number back so another line can store it and multiply it."},"options":{"a":"Use `return` inside the function and store the result in a variable.","b":"Use `print()` inside the function and assume later code can multiply the printed text.","c":"Add more parameters until the function becomes reusable.","d":"Put the multiplication inside the function even if other code needs the original result."}},"pvrs-mc-1":{"title":"Choose the true statements","prompt":"Which statements about `print()` and `return` are true? Choose all that apply.","hint":"Separate what the user sees in the output panel from what the rest of the program can keep using.","help":{"concept":"`print()` is for display, while `return` is for producing a value that calling code can use.","hint_1":"A returned value can be assigned to a variable; printed output is just displayed.","hint_2":"Pick the options that describe display versus reusable results correctly."},"options":{"a":"`print()` displays output for the user to see.","b":"`return` can send a value back to the code that called the function.","c":"A function can never use both `print()` and `return`.","d":"If a function only prints a value, that printed value is automatically stored in a variable."}},"pvrs-mc-2":{"title":"Ways to use a returned value","prompt":"A function `make_label(name)` returns a string. Which lines use that returned value correctly? Choose all that apply.","hint":"Look for lines where the function call becomes part of another expression or is stored for later use.","help":{"concept":"A returned value behaves like any other value, so it can be stored, printed, or combined with other strings.","hint_1":"If the function returns text, valid uses include assignment and string concatenation.","hint_2":"Choose the lines where the function call is treated like a string value produced by the function."},"options":{"a":"`label = make_label(\"Mia\")`","b":"`print(make_label(\"Mia\"))`","c":"`message = make_label(\"Mia\") + \"!\"`","d":"`return = make_label(\"Mia\")`"}},"pvrs-dr-1":{"title":"Order the return flow","prompt":"Put these steps in the correct order for code that returns a value and then prints it.","hint":"Start with the function call, then think about what the function sends back, then what gets displayed.","help":{"concept":"When a function returns a value, the call runs first, the value comes back to the caller, it can be stored, and then it may be printed.","hint_1":"The function must run before a variable can receive its returned value.","hint_2":"The displayed output happens after the returned value has already come back and been used by the calling code."},"tokens":{"t1":"Call the function.","t2":"The function computes a result.","t3":"The function returns the value.","t4":"The caller stores or uses that value.","t5":"`print()` can display it."}},"pvrs-dr-2":{"title":"Build a reusable pattern","prompt":"Arrange these code pieces into a sensible pattern for using a returned value.","hint":"First define the function, then call it, then store the result, then display or reuse it.","help":{"concept":"A common pattern is define a function with `return`, call it, save the returned value, and then use that value later.","hint_1":"The function definition must come before the call that uses it.","hint_2":"After the call returns a value, that value should be assigned before a later `print()` uses the variable."},"tokens":{"t1":"`def add_one(n):`","t2":"` return n + 1`","t3":"`result = add_one(4)`","t4":"`print(result)`"}},"pvrs-fb-1":{"title":"Complete the keyword","prompt":"Choose the word that correctly completes the function so it sends a value back.","hint":"The missing word should give the result back to the caller.","help":{"concept":"A function uses a dedicated statement to send a computed value back to its caller.","hint_1":"`print` shows output, but this blank needs the keyword that hands the value back.","hint_2":"Choose the Python keyword used before an expression like `n * 2` when a function should produce a reusable result."},"template":"def double(n):\n [blank1] n * 2","choices":["print","return","input","def"]},"pvrs-fb-2":{"title":"Complete the display line","prompt":"Choose the code that displays the returned value from `get_name()` in the output panel.","hint":"The function already returns the value, so the missing part should show that value.","help":{"concept":"If a function returns a value and you want to display it, wrap the function call in `print()`.","hint_1":"The blank is not inside the function definition; it is the line that shows the returned result.","hint_2":"Choose the option that calls the function and sends its result to the output panel."},"template":"[blank1]","choices":["print(get_name())","return get_name()","def get_name()","get_name = print()"]},"pvrs-code-1":{"title":"Return a doubled value","prompt":"Write `double_number(n)` so it returns double the input instead of printing it.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def double_number(n):\n # return double the input\n pass","solutionCode":"def double_number(n):\n return n * 2"},"pvrs-code-2":{"title":"Return a greeting string","prompt":"Write `make_greeting(name)` so it returns a greeting string like `Hello, Ava`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_greeting(name):\n # return a greeting like Hello, Ava\n pass","solutionCode":"def make_greeting(name):\n return \"Hello, \" + name"},"pvrs-code-3":{"title":"Return a total instead of printing it","prompt":"Write `add_prices(price1, price2)` so it returns the total of the two prices instead of printing it.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def add_prices(price1, price2):\n # return the total of the two prices\n pass","solutionCode":"def add_prices(price1, price2):\n return price1 + price2"},"try-print-vs-return-checkpoint":{"title":"Return, then print","prompt":"Define `add(a, b)` so it returns the sum. Then print `add(3, 4)`.","hint":"The function should return the value; the call site should print it.","help":{"concept":"Returning a value and printing a value are separate actions.","hint_1":"The function should return the value; the call site should print it.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def add(a, b):\n # Return the sum.\n pass\n\n# Print the result of add(3, 4).\n","solutionCode":"def add(a, b):\n return a + b\n\nprint(add(3, 4))\n"},"try-print-vs-return-sketch0":{"title":"Call a display-only function directly","prompt":"The starter defines `show_status(text)` as a display-only function: it prints the text and returns no value. The final line incorrectly wraps the call in `print(...)`, which would display an extra `None`. Change only the caller behavior so the status is displayed exactly once.","hint":"Because `show_status` already prints, call `show_status(status)` directly.","help":{"concept":"A display-only function should usually be called directly rather than wrapped in another `print()`.","hint_1":"Keep `print(text)` inside `show_status`.","hint_2":"Replace `print(show_status(status))` with a standalone `show_status(status)` call."},"starterCode":"def show_status(text):\n print(text)\n\nstatus = input()\nprint(show_status(status))\n","solutionCode":"def show_status(text):\n print(text)\n\nstatus = input()\nshow_status(status)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `show_status(...)` because that function call is explicitly required by the prompt."}}},"try-print-vs-return-sketch1":{"title":"Store and reuse a returned number","prompt":"The starter defines `double(number)` so it returns twice the number. Read the existing input into `number`, store `double(number)` in a variable named `result`, then print `result + 1`.","hint":"The returned number can be saved first and used in a later expression.","help":{"concept":"A returned value can be assigned to a variable and then reused in additional calculations.","hint_1":"Write `result = double(number)`.","hint_2":"Then print `result + 1`."},"starterCode":"def double(number):\n return number * 2\n\nnumber = int(input())\n# Store double(number) in result.\n# Then print result + 1.\n","solutionCode":"def double(number):\n return number * 2\n\nnumber = int(input())\nresult = double(number)\nprint(result + 1)\n","sourceChecks":{"0":{"message":"Call `double(...)` because that function call is explicitly required by the prompt."}}},"try-print-vs-return-sketch2":{"title":"Fix a function that prints instead of returning","prompt":"The starter's `make_label(item)` prints the label, but the caller needs to store that label and add `!`. Fix `make_label` so it returns `\"Item: \" + item` instead of printing it. Keep the caller-side assignment and final print.","hint":"The caller needs a string value in `label`, so the function must return the string.","help":{"concept":"Printing inside the function is not enough when the caller must store and transform the result.","hint_1":"Replace the function body's `print(...)` with `return \"Item: \" + item`.","hint_2":"Leave `label = make_label(item)` and `print(label + \"!\")` outside the function."},"starterCode":"def make_label(item):\n print(\"Item: \" + item)\n\nitem = input()\nlabel = make_label(item)\nprint(label + \"!\")\n","solutionCode":"def make_label(item):\n return \"Item: \" + item\n\nitem = input()\nlabel = make_label(item)\nprint(label + \"!\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `make_label(...)` because that function call is explicitly required by the prompt."}}},"sc-print-only-result":{"title":"What does the caller receive?","prompt":"A function contains `print(\"Ready\")` but no `return`. What value does the function call give back to its caller?","hint":"Visible output and a returned value are separate things.","help":{"concept":"A function with no explicit `return` gives the caller `None`, even if the function prints something.","hint_1":"`print(\"Ready\")` displays text in the output panel.","hint_2":"Because there is no `return`, the call itself evaluates to `None`."},"options":{"a":"\"Ready\"","b":"None","c":"print","d":"The function name"}},"sc-display-only-call":{"title":"Call a display-only function","prompt":"`show_status(text)` prints its text and does not return a value. Which line displays `Ready` once without also displaying `None`?","hint":"If the function already prints, call it directly.","help":{"concept":"Wrapping a display-only function call in another `print()` prints the function's implicit `None` result too.","hint_1":"`show_status(\"Ready\")` already causes the function body to print `Ready`.","hint_2":"Avoid `print(show_status(\"Ready\"))` when the function itself is responsible for display."},"options":{"a":"show_status(\"Ready\")","b":"print(show_status(\"Ready\"))","c":"return show_status(\"Ready\")","d":"show_status = \"Ready\""}},"sc-reuse-returned-value":{"title":"Reuse a function result","prompt":"`double(6)` returns `12`. Which code correctly stores that returned value and then uses it in another calculation?","hint":"Store the function call on the right side of an assignment.","help":{"concept":"A returned value behaves like another value: it can be assigned to a variable and used later.","hint_1":"First save `double(6)` in a variable.","hint_2":"Then use that variable in the later expression."},"options":{"a":"result = double(6)\nprint(result + 1)","b":"print = double(6)\nresult + 1","c":"double = 6\nprint(double + 1)","d":"return double(6)\nprint(result)"}},"sc-fix-print-return-bug":{"title":"Fix a print-versus-return bug","prompt":"The caller does `label = make_label(\"Book\")` and then needs `label + \"!\"`. Inside `make_label`, which statement should produce the label text?","hint":"The caller needs to receive a string value, not just see it displayed.","help":{"concept":"When later code must store or combine a function result, the function should return that result.","hint_1":"Printing the label would display it but leave `label` as `None`.","hint_2":"Return the string so the caller can concatenate `\"!\"`."},"options":{"a":"print(\"Item: \" + item)","b":"return \"Item: \" + item","c":"input(\"Item: \" + item)","d":"def \"Item: \" + item"}}},"tryIt":{"try_print_vs_return_checkpoint":{"title":"Try it yourself","prompt":"Define `add(a, b)` so it returns the sum. Then print `add(3, 4)`."},"try_print_vs_return_sketch0":{"title":"Try it yourself","prompt":"Call a display-only function directly so its implicit `None` result is not printed."},"try_print_vs_return_sketch1":{"title":"Try it yourself","prompt":"Store a returned number and reuse it in another expression."},"try_print_vs_return_sketch2":{"title":"Try it yourself","prompt":"Fix a function that prints when its caller needs a returned string."},"allowReveal":true}},"scope-and-local-variables":{"label":"Scope and Local Variables","summary":"Use local variables safely inside functions, recognize that parameters are local names, keep same-named outside values separate, and return local results when the caller needs them.","cards":{"sketch0":{"title":"Local variables belong to the function call"},"sketch1":{"title":"Parameters are local, even when names match outside"},"sketch2":{"title":"Return local results to the caller"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-q1":{"title":"Find the local variable","prompt":"In this code, which name is local to the function?\n\n```python\ncolor = \"blue\"\n\ndef paint():\n shade = \"dark\"\n return color + \" \" + shade\n```","hint":"Look for the name created inside `paint()`.","help":{"concept":"A local variable is created inside a function and is meant to be used only during that function call.","hint_1":"`color` is assigned before the function starts. Check which name is assigned inside the function body.","hint_2":"The local name is the one introduced on the line `... = \"dark\"` inside `paint()`."},"options":{"a":"color","b":"paint","c":"shade","d":"return"}},"sc-q2":{"title":"Parameter scope","prompt":"What is true about a parameter like `name` in `def greet(name):`?","hint":"Think about where the parameter can be used directly.","help":{"concept":"Parameters are local names created for a function call, so they belong to that function's scope.","hint_1":"A parameter gets its value when the function is called, not everywhere in the program.","hint_2":"Ask whether `name` is meant to exist only inside `greet(...)` or in all code automatically."},"options":{"a":"It exists only inside the function call unless returned or passed elsewhere.","b":"It automatically becomes a global variable.","c":"It can only store numbers.","d":"It disappears before the function starts."}},"mc-q1":{"title":"Choose the local names","prompt":"Which names are local in this code? Choose all that apply.\n\n```python\ntax = 5\n\ndef total(price):\n fee = 2\n final_price = price + fee + tax\n return final_price\n```","hint":"Reject any choice that changes the named values, branch order, or output.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"tax","b":"price","c":"fee","d":"final_price"}},"mc-q2":{"title":"Why local scope helps","prompt":"Why are local variables useful? Choose all correct answers.","hint":"Think about how functions stay organized and avoid name mix-ups.","help":{"concept":"Local scope helps functions stay independent, readable, and safer because temporary names do not leak into the rest of the program.","hint_1":"A good answer should mention keeping function work separate or preventing accidental reuse of temporary names.","hint_2":"Look for benefits like reducing conflicts and making each function manage its own temporary data."},"options":{"a":"They help prevent temporary names inside one function from interfering with other code.","b":"They make it easier for a function to keep its own working values.","c":"They force every variable in a program to have the same name.","d":"They automatically print returned values."}},"dr-q1":{"title":"Order a function call","prompt":"Put these steps in the correct order for what happens when `double(4)` runs in a function that returns `number * 2`.","hint":"Start with the call, then the parameter gets a value, then the calculation happens, then the result is returned.","help":{"concept":"A function call gives values to parameters, runs the function body, computes a result, and then returns that result.","hint_1":"The parameter cannot be used until the function is called with an argument.","hint_2":"After `number` gets `4`, the multiplication happens before the value is sent back."},"tokens":{"t1":"Call `double(4)`","t2":"Set local parameter `number` to `4`","t3":"Compute `number * 2`","t4":"Return the result"}},"dr-q2":{"title":"Trace local variable creation","prompt":"Arrange the steps to describe this function call correctly.\n\n```python\ndef greet(person):\n message = \"Hi \" + person\n return message\n```","hint":"The argument fills the parameter first, then the local variable is built, then the function returns it.","help":{"concept":"During a function call, the argument becomes the parameter value, local variables are created from that value, and the return statement sends the final result back.","hint_1":"`person` gets its value before `message` can be created.","hint_2":"The returned value comes last, after the string has been built inside the function."},"tokens":{"t1":"Pass an argument into `person`","t2":"Create local variable `message`","t3":"Build the text `\"Hi \" + person`","t4":"Return `message`"}},"fb-q1":{"title":"Complete the local assignment","prompt":"Choose the missing word to make `score` a local variable inside the function.","hint":"The blank should be the variable name being assigned inside the function.","help":{"concept":"A variable assigned inside a function becomes local to that function call.","hint_1":"The line is creating a new name inside the function body.","hint_2":"Match the blank to the variable described as belonging only to the function call."},"template":"def show_score():\n [blank1] = 10\n return score","choices":["score","return","show_score","def"]},"fb-q2":{"title":"Complete the parameter use","prompt":"Fill the blank with the correct local name.","hint":"Use the parameter name from the function header.","help":{"concept":"A parameter is a local name, so code inside the function should use that parameter name directly.","hint_1":"The function header already tells you the local name to use.","hint_2":"Look at the parameter position inside the function header and choose the same name used by the function body."},"template":"def triple(value):\n return [blank1] * 3","choices":["value","triple","return","3"]},"code-q1":{"title":"Return a local calculation","prompt":"Write `add_tax(price)` so it calculates `price + 5`, stores that result in a local variable named `total`, and then returns `total`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def add_tax(price):\n # store the result in a local variable named total\n # then return it\n pass","solutionCode":"def add_tax(price):\n total = price + 5\n return total","checks":{"0":{"message":"add_tax should return price plus 5."},"1":{"message":"add_tax should work for a different number too."},"2":{"message":"Return the value instead of printing it."}}},"code-q2":{"title":"Use a parameter as a local name","prompt":"Write `make_label(word)` so it builds the finished string in a local variable named `label`, then returns `label`.","hint":"Read the task \"Use a parameter as a local name\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_label(word):\n # create a local variable named label\n # return the finished string\n pass","solutionCode":"def make_label(word):\n label = \"Item: \" + word\n return label","checks":{"0":{"message":"make_label should prefix the word with `Item: `."},"1":{"message":"make_label should work with another input word."},"2":{"message":"Return the string instead of printing it."}}},"code-q3":{"title":"Compute with two local variables","prompt":"Write `rectangle_area(width, height)` so it computes the area, stores it in a local variable named `area`, and returns `area`.","hint":"Read the task \"Compute with two local variables\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def rectangle_area(width, height):\n # create a local variable named area\n # return the area\n pass","solutionCode":"def rectangle_area(width, height):\n area = width * height\n return area","checks":{"0":{"message":"rectangle_area should multiply width by height."},"1":{"message":"rectangle_area should work for another pair of numbers."},"2":{"message":"Return the area instead of printing it."}}},"try-scope-and-local-variables-checkpoint":{"title":"Use a local variable","prompt":"Define `make_message(name)` with a local variable named `message`, then return it. Print the result for `Ava`.","hint":"Create the message inside the function.","help":{"concept":"A local variable exists inside the function where it is created.","hint_1":"Create the message inside the function.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def make_message(name):\n # Create a local variable named message.\n pass\n\nprint(make_message(\"Ava\"))\n","solutionCode":"def make_message(name):\n message = f\"Hello, {name}!\"\n return message\n\nprint(make_message(\"Ava\"))\n"},"try-scope-and-local-variables-sketch0":{"title":"Create and return a local calculation","prompt":"Complete `add_fee(price)`. Inside the function, create the local variable a local variable named `total` that stores the result of increasing `price` by 3, then return `total`. The caller already reads a price and prints the returned result.","hint":"Both the `total` assignment and `return total` belong inside the function body.","help":{"concept":"A local variable can hold an intermediate result while the function is running.","hint_1":"Create `total = price + 3` under the `def` line.","hint_2":"Return that local value with `return total`."},"starterCode":"def add_fee(price):\n # Create local variable total = price + 3.\n # Then return total.\n pass\n\nprice = int(input())\nprint(add_fee(price))\n","solutionCode":"def add_fee(price):\n total = price + 3\n return total\n\nprice = int(input())\nprint(add_fee(price))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-scope-and-local-variables-sketch1":{"title":"Keep an outside value separate from a parameter","prompt":"The program reads an outside variable named `count`. Complete `next_count(count)` so it creates local variable a local variable named `updated` that stores `count` increased by 1 and returns `updated`. The program must print the returned next count and then print the original outside `count`, which should remain unchanged.","hint":"The parameter named `count` is local to `next_count`; calculate a new local `updated` value instead of changing the outside assignment.","help":{"concept":"A parameter can have the same name as an outside variable without turning that outside variable into the function's local storage.","hint_1":"Inside the function, write `updated = count + 1`.","hint_2":"Return `updated`; do not add another top-level assignment to `count`."},"starterCode":"count = int(input())\n\ndef next_count(count):\n # Create local variable updated = count + 1.\n # Return updated.\n pass\n\nprint(next_count(count))\nprint(count)\n","solutionCode":"count = int(input())\n\ndef next_count(count):\n updated = count + 1\n return updated\n\nprint(next_count(count))\nprint(count)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-scope-and-local-variables-sketch2":{"title":"Return a local value to the caller","prompt":"The starter creates local variable `message` inside `make_message(name)`, but then incorrectly tries to use `message` outside the function. Fix the program by returning the local `message`, storing the returned value in a caller-side variable named `result`, and printing `result`.","hint":"The outside code cannot reach the function's local `message` directly; send its value back with `return`.","help":{"concept":"Returning a local value does not expose the local variable itself; it gives the caller a value that the caller can store under its own name.","hint_1":"Inside the function, add `return message`.","hint_2":"Outside the function, use `result = make_message(name)` and then `print(result)`."},"starterCode":"def make_message(name):\n message = \"Hello, \" + name\n # Return the local message so the caller can use its value.\n pass\n\nname = input()\nmake_message(name)\nprint(message)\n","solutionCode":"def make_message(name):\n message = \"Hello, \" + name\n return message\n\nname = input()\nresult = make_message(name)\nprint(result)\n","sourceChecks":{"0":{"message":"Call `make_message(...)` because that function call is explicitly required by the prompt."}}},"sc-local-variable":{"title":"Identify a local variable","prompt":"In `def total(price): fee = 2; return price + fee`, which name is created locally inside the function body?","hint":"Look for the assignment that happens inside the function.","help":{"concept":"A name assigned inside a function is local to that function call unless Python is explicitly told otherwise.","hint_1":"`price` is a parameter; it receives its value when the function is called.","hint_2":"`fee = 2` creates a working variable inside the function body."},"options":{"a":"fee","b":"total","c":"return","d":"def"}},"sc-local-outside":{"title":"Use a local name outside the function","prompt":"A function creates `message = \"Ready\"` inside its body but does not return it. What happens if code after the function call tries `print(message)`?","hint":"The name was created only inside the function.","help":{"concept":"A local variable is not directly available to unrelated code after the function call finishes.","hint_1":"Displaying or returning a value is different from making the local variable itself available outside.","hint_2":"The outside code does not have its own `message` assignment."},"options":{"a":"It prints Ready","b":"Python reports that `message` is not defined there","c":"It automatically calls the function again","d":"It turns `message` into a parameter"}},"sc-parameter-local":{"title":"Parameter scope","prompt":"What is true about `count` in `def add_one(count):`?","hint":"A parameter is a name that receives an argument for one function call.","help":{"concept":"Parameters are local names inside the function call.","hint_1":"The caller supplies an argument value.","hint_2":"Inside the function, that value is available through the local parameter name `count`."},"options":{"a":"It is local to the function call","b":"It automatically changes every outside variable named count","c":"It can only hold integers","d":"It exists before the function is called"}},"sc-same-name-separate":{"title":"Same name, separate value","prompt":"Suppose `count = 5` exists outside a function and `def add_one(count): return count + 1`. After `print(add_one(count))`, what is the outside `count` still equal to?","hint":"The parameter receives the value 5, but the function does not assign to the outside variable.","help":{"concept":"A parameter can have the same spelling as an outside variable while still being a separate local name.","hint_1":"The call returns `6`.","hint_2":"Nothing in the function changes the caller's `count = 5` assignment."},"options":{"a":"5","b":"6","c":"None","d":"The function name"}}},"tryIt":{"try_scope_and_local_variables_checkpoint":{"title":"Try it yourself","prompt":"Define `make_message(name)` with a local variable named `message`, then return it. Print the result for `Ava`."},"try_scope_and_local_variables_sketch0":{"title":"Try it yourself","prompt":"Complete `add_fee(price)`. Inside the function, create the local variable a local variable named `total` that stores the result of increasing `price` by 3, then return `total`. The caller already reads a price and prints the returned result."},"try_scope_and_local_variables_sketch1":{"title":"Try it yourself","prompt":"The program reads an outside variable named `count`. Complete `next_count(count)` so it creates local variable a local variable named `updated` that stores `count` increased by 1 and returns `updated`. The program must print the returned next count and then print the original outside `count`, which should remain unchanged."},"try_scope_and_local_variables_sketch2":{"title":"Try it yourself","prompt":"Return a local result and store that value under a caller-side variable."},"allowReveal":true}},"using-imports-and-helper-files":{"label":"Using Imports and Helper Files","summary":"Move reusable functions into sibling Python module files, import those functions into `main.py`, and connect multiple focused modules without changing the program's behavior.","cards":{"sketch0":{"title":"A Python file can be imported as a module"},"sketch1":{"title":"One module can hold related helpers"},"sketch2":{"title":"main.py can connect multiple helper modules"},"quiz":{"title":"Check your understanding"}},"quiz":{"q1":{"title":"Why split code into files?","prompt":"Why would a Python project put reusable functions in files such as `tools/names.py` instead of putting every line in `main.py`?","hint":"Think about keeping the main app readable and reusing the same logic later.","help":{"concept":"A module file can hold reusable functions. `main.py` can stay focused on the app flow: read input, call functions, and print results.","hint_1":"Look for the option about organization and reuse.","hint_2":"The goal is not to make more work. The goal is to keep each file responsible for a clear job."},"options":{"a":"It keeps reusable code organized and lets `main.py` import it","b":"It makes Python ignore errors in the imported file","c":"It means the project can only run with one input value","d":"It prevents functions from returning values"}},"q2":{"title":"Choose the direct import","prompt":"You created `tools/names.py` with a function named `clean_name`. Which line imports that function into `main.py`?","hint":"The path uses the folder name, then the file name without `.py`, then the function name.","help":{"concept":"To import from a module inside a folder, use `from folder.file import function`. For `tools/names.py`, the module path is `tools.names`.","hint_1":"Do not include `.py` in the import line.","hint_2":"The correct form starts with `from tools.names import ...`."},"options":{"a":"from tools.names import clean_name","b":"from tools/names.py import clean_name","c":"import clean_name from tools.names","d":"from clean_name import tools.names"}},"q3":{"title":"Good module responsibilities","prompt":"Choose all examples that are good jobs for a small module file in this lesson.","hint":"Pick jobs that are reusable and focused.","help":{"concept":"Good module files usually hold related functions, such as text cleanup, formatting, scoring, or report building.","hint_1":"A module should have a clear purpose.","hint_2":"Avoid choices that put unrelated random code into one file."},"options":{"a":"`tools/names.py` cleans and formats names","b":"`tools/badges.py` builds badge text from a name and role","c":"`tools/random_everything.py` mixes unrelated code with no clear job","d":"`main.py` must copy every function from every module before it can run"}},"q4":{"title":"Valid imported calls","prompt":"Which calls are valid after the matching import? Choose all correct answers.","hint":"Match the call style to the import style.","help":{"concept":"After `from tools.names import clean_name`, call `clean_name(...)` directly. After `import tools.badges as badges`, call `badges.make_badge(...)`.","hint_1":"Direct imports use the function name directly.","hint_2":"Alias imports use the alias before the dot."},"options":{"a":"After `from tools.names import clean_name`, use `clean_name(\" ava \")`","b":"After `import tools.badges as badges`, use `badges.make_badge(\"Ava\", \"coder\")`","c":"After `from tools.names import clean_name`, use `tools.names.clean_name(\"Ava\")` without importing `tools`","d":"After `import tools.badges as badges`, use `make_badge.badges(\"Ava\")`"}},"q5":{"title":"Order the module workflow","prompt":"Put these steps in the order you would use when adding your own module file to a small app.","hint":"Create the file before importing from it.","help":{"concept":"Python can import a module only after the file exists in the expected folder path. Then `main.py` can call functions from that file.","hint_1":"The folder and file come before the import.","hint_2":"The function call happens after the import line."},"tokens":{"t1":"Create the `tools` folder","t2":"Create a module file such as `tools/names.py`","t3":"Define a function inside that module file","t4":"Import and call the function from `main.py`"}},"q6":{"title":"Build the import flow","prompt":"Arrange these lines so `main.py` imports a formatter and prints the returned result.","hint":"Import first, then call, then print.","help":{"concept":"A main file usually imports the function it needs, calls it with data, and prints or stores the returned value.","hint_1":"The import line must run before the function call.","hint_2":"Print the stored message after the function returns it."},"tokens":{"t1":"from tools.reports import mission_report","t2":"message = mission_report(\"SCOUT badge: Zoe\", 18)","t3":"print(message)"}},"q7":{"title":"Complete the function import","prompt":"Fill in the missing function name to import it from `tools.names`.","hint":"This is the function that cleans extra spaces and capitalization.","help":{"concept":"`from tools.names import clean_name` imports the `clean_name` function from the `names.py` file inside the `tools` folder.","hint_1":"The missing word is the function name, not the folder name.","hint_2":"Choose the name that describes cleaning a name."},"template":"from tools.names import [blank1]","choices":["clean_name","tools","names.py","input"]},"q8":{"title":"Complete the module path","prompt":"Fill in the missing folder name in this import line.","hint":"The module files for this project live inside one folder.","help":{"concept":"The import path `tools.badges` means Python should look for `badges.py` inside the `tools` folder.","hint_1":"Do not type `.py` in the import path.","hint_2":"Choose the folder that contains `badges.py`."},"template":"from [blank1].badges import make_badge","choices":["tools","badges.py","main","print"]},"q9":{"title":"Create a name-cleaning module","prompt":"Practice creating and importing a small helper module. Create a `tools` folder, add `tools/names.py`, and define `clean_name(text)` there. Then import `clean_name` from `tools.names` in `main.py`, clean the input name, and print it. For input `aVA`, the output should be `Ava`.","hint":"The required path is `tools/names.py`. The import line in `main.py` should be `from tools.names import clean_name`.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"# Create a folder named tools.\n# Inside it, create tools/names.py.\n# Define clean_name(text) in that file.\n\nraw_name = input()\n\n# Import clean_name from tools.names.\n# Print the cleaned name.\n","solutionFiles":{"main_py":{"content":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Import from tools.names."},"1":{"message":"Define clean_name(text) inside tools/names.py."},"2":{"message":"clean_name should strip whitespace."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"q10":{"title":"Add a badge module","prompt":"The helper folder needs one more tool. Create `tools/badges.py`, import `make_badge` from `tools.badges`, clean the input name, build the badge text, and print it.\n\nFor example, if the inputs are `lina` and `artist`, your program should print:\n`ARTIST badge: Lina`.","hint":"Create `tools/badges.py`, then import with `from tools.badges import make_badge`.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"from tools.names import clean_name\n\nraw_name = input()\nrole = input()\n\n# Create tools/badges.py.\n# Import make_badge from tools.badges.\n# Clean the name, build the badge, and print it.\n","starterFiles":{"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Import from tools.badges."},"1":{"message":"Define make_badge in tools/badges.py."},"2":{"message":"make_badge should uppercase the role."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"q11":{"title":"Build a mission report module","prompt":"Practice connecting helper modules into one report. Create `tools/reports.py`, import `mission_report` from `tools.reports`, and print the finished mission report. For inputs `zoe`, `scout`, and `18`, the output should be `Mission report: SCOUT badge: Zoe has 18 points`.","hint":"This step combines three files: `tools/names.py`, `tools/badges.py`, and your new `tools/reports.py`.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\npoints = int(input())\n\n# Create tools/reports.py.\n# Import mission_report from tools.reports.\n# Print the final mission report.\n","starterFiles":{"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\nfrom tools.reports import mission_report\n\nraw_name = input()\nrole = input()\npoints = int(input())\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(mission_report(badge, points))\n"},"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"},"tools_reports_py":{"content":"def mission_report(badge, points):\n return f\"Mission report: {badge} has {points} points\"\n"}},"sourceChecks":{"0":{"message":"Import from tools.reports."},"1":{"message":"Define mission_report in tools/reports.py."},"2":{"message":"Call mission_report() from main.py."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\nfrom tools.reports import mission_report\n\nraw_name = input()\nrole = input()\npoints = int(input())\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(mission_report(badge, points))\n"},"try-using-imports-and-helper-files-checkpoint":{"title":"Import from a helper file","prompt":"Build this as a small two-file program.\n\n1. Create `tools/names.py`.\n2. In `tools/names.py`, define `clean_name(text)`.\n3. In `main.py`, import `clean_name` with `from tools.names import clean_name`.\n4. Read one name with `input()`, clean it, and print the result.","hint":"Create `tools/names.py` first, then import `clean_name` in `main.py`.","help":{"concept":"A helper module lets `main.py` stay short while another file handles one focused job.","hint_1":"Put `clean_name(text)` in `tools/names.py`.","hint_2":"In `main.py`, import `clean_name`, call it with the raw input, and print the cleaned name."},"starterCode":"raw_name = input()\n\n# Import clean_name from tools.names.\n# Print the cleaned name.\n","solutionFiles":{"main_py":{"content":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Import from tools.names."},"1":{"message":"Define clean_name(text) inside tools/names.py."},"2":{"message":"clean_name should strip whitespace."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"try-using-imports-and-helper-files-sketch0":{"title":"Move a helper into names.py","prompt":"This program already works, but `clean_name` is still defined inside `main.py`. Refactor it without changing the output: move `clean_name(text)` into a new sibling file named `names.py`, then import it in `main.py` with a from-import that brings `clean_name` in from the `names` module.","hint":"The function body moves to `names.py`; `main.py` keeps the input and output flow.","help":{"concept":"A Python helper file becomes a module that another file can import.","hint_1":"Create `names.py` beside `main.py` and put `clean_name(text)` there.","hint_2":"Remove the local definition from `main.py` and add `from names import clean_name`."},"starterCode":"def clean_name(text):\n return text.strip().title()\n\nraw_name = input()\nprint(clean_name(raw_name))\n","solutionFiles":{"main_py":{"content":"from names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `clean_name` from `names`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"clean_name should strip spaces."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n","starterFiles":{"main_py":{"content":"def clean_name(text):\n return text.strip().title()\n\nraw_name = input()\nprint(clean_name(raw_name))\n"}}},"try-using-imports-and-helper-files-sketch1":{"title":"Move related helpers into text_tools.py","prompt":"This working program defines two related text helpers in `main.py`. Refactor it without changing the output: move both `clean_word(text)` and `make_label(word)` into a sibling file named `text_tools.py`. In `main.py`, import both functions with one from-import that brings both `clean_word` and `make_label` in from the `text_tools` module.","hint":"Both related helper functions move to the same module; the input and print stay in `main.py`.","help":{"concept":"One module can expose several related helper functions.","hint_1":"Create `text_tools.py` with both function definitions.","hint_2":"In `main.py`, import both names from `text_tools` and keep calling them in the existing flow."},"starterCode":"def clean_word(text):\n return text.strip().lower()\n\ndef make_label(word):\n return \"Word: \" + word\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n","solutionFiles":{"main_py":{"content":"from text_tools import clean_word, make_label\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"},"text_tools_py":{"content":"def clean_word(text):\n return text.strip().lower()\n\ndef make_label(word):\n return \"Word: \" + word\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `clean_word` from `text_tools`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"solutionCode":"from text_tools import clean_word, make_label\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n","starterFiles":{"main_py":{"content":"def clean_word(text):\n return text.strip().lower()\n\ndef make_label(word):\n return \"Word: \" + word\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n"}}},"try-using-imports-and-helper-files-sketch2":{"title":"Connect two existing helper modules","prompt":"`names.py` already defines `clean_name(text)` and `badges.py` already defines `make_badge(name, role)`. `main.py` currently duplicates both jobs inline. Refactor only the main flow so it imports both helpers, cleans the input name with `clean_name`, then builds the badge with `make_badge`. The program's output must stay the same.","hint":"The helper files are already complete; `main.py` should import and connect them.","help":{"concept":"A main file can coordinate multiple focused modules by passing one helper's returned value into another.","hint_1":"Import `clean_name` from `names` and `make_badge` from `badges`.","hint_2":"Use `name = clean_name(raw_name)` and then `print(make_badge(name, role))`."},"starterCode":"raw_name = input()\nrole = input()\n\nname = raw_name.strip().title()\nprint(f\"{role.upper()} badge: {name}\")\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\n\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Import the sibling `names` helper module in `main.py` as the prompt requires."},"1":{"message":"Import the sibling `badges` helper module in `main.py` as the prompt requires."},"2":{"message":"Call `clean_name(...)` because that function call is explicitly required by the prompt."},"3":{"message":"Call `make_badge(...)` because that function call is explicitly required by the prompt."},"4":{"message":"Call clean_name in main.py."},"5":{"message":"Call make_badge in main.py."}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\n\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n","starterFiles":{"main_py":{"content":"raw_name = input()\nrole = input()\n\nname = raw_name.strip().title()\nprint(f\"{role.upper()} badge: {name}\")\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}}},"sc-file-to-module":{"title":"Import from a sibling file","prompt":"`names.py` is beside `main.py` and defines `clean_name`. Which line imports that function into `main.py`?","hint":"Use the Python file name without the `.py` extension.","help":{"concept":"A sibling file such as `names.py` can be imported by its module name `names`.","hint_1":"The module part is `names`, not `names.py`.","hint_2":"A direct function import uses `from names import clean_name`."},"options":{"a":"from names import clean_name","b":"from names.py import clean_name","c":"from clean_name import names","d":"import clean_name from names"}},"sc-direct-call":{"title":"Call a directly imported function","prompt":"After `from names import clean_name`, which expression calls the imported function with `raw_name`?","hint":"A directly imported function is called by its function name.","help":{"concept":"With `from module import function`, the imported function name is available directly in the importing file.","hint_1":"You do not include `.py` when calling the function.","hint_2":"Use `clean_name(raw_name)`."},"options":{"a":"clean_name(raw_name)","b":"names.py.clean_name(raw_name)","c":"import clean_name(raw_name)","d":"from clean_name(raw_name)"}},"sc-module-responsibility":{"title":"Choose a focused helper module","prompt":"Which file responsibility is the clearest fit for a small helper module?","hint":"Keep related reusable functions together.","help":{"concept":"A helper module is easiest to understand when its functions serve one related responsibility.","hint_1":"Name-related cleanup functions belong naturally together.","hint_2":"Avoid a file that mixes unrelated input, math, formatting, and random experiments."},"options":{"a":"`names.py` contains functions for cleaning and formatting names","b":"`everything.py` contains unrelated code from the entire program","c":"`main.py` copies every helper function before using it","d":"`random.py` stores unrelated temporary experiments"}},"sc-main-role":{"title":"What main.py should do","prompt":"After name cleanup lives in `names.py` and badge formatting lives in `badges.py`, what is a good responsibility for `main.py`?","hint":"The main file can coordinate the app instead of duplicating helper logic.","help":{"concept":"`main.py` can read input, call imported helpers, and connect their returned values into the program flow.","hint_1":"The helper modules already own cleanup and badge formatting.","hint_2":"The main file should import and call them rather than rewrite them."},"options":{"a":"Read input and connect the imported helper functions","b":"Copy the full contents of every helper file","c":"Rename every imported function before it can run","d":"Avoid calling any helper function"}}},"tryIt":{"try_using_imports_and_helper_files_checkpoint":{"title":"Try it yourself","prompt":"Build this as a small two-file program.\n\n1. Create `tools/names.py`.\n2. In `tools/names.py`, define `clean_name(text)`.\n3. In `main.py`, import `clean_name` with `from tools.names import clean_name`.\n4. Read one name with `input()`, clean it, and print the result."},"try_using_imports_and_helper_files_sketch0":{"title":"Try it yourself","prompt":"This program already works, but `clean_name` is still defined inside `main.py`. Refactor it without changing the output: move `clean_name(text)` into a new sibling file named `names.py`, then import it in `main.py` with a from-import that brings `clean_name` in from the `names` module."},"try_using_imports_and_helper_files_sketch1":{"title":"Try it yourself","prompt":"This working program defines two related text helpers in `main.py`. Refactor it without changing the output: move both `clean_word(text)` and `make_label(word)` into a sibling file named `text_tools.py`. In `main.py`, import both functions with one from-import that brings both `clean_word` and `make_label` in from the `text_tools` module."},"try_using_imports_and_helper_files_sketch2":{"title":"Try it yourself","prompt":"Refactor `main.py` to connect two existing sibling helper modules."},"allowReveal":true}}},"python-7-files-exceptions-and-data-cleaning":{"module-7-clean-student-records":{"label":"Module Project: Clean Student Records","summary":"Turn a messy student CSV export into a validated clean CSV by combining DictReader, cleaning functions, specific exception handling, lists, and text-file writing, while keeping row-cleaning logic in a reusable helper module.","cards":{"sketch0":{"title":"A messy student export needs a reliable cleaner"},"project":{"title":"Clean Student Records"}},"projectSteps":{"mp_1":{"title":"Build the cleaning helper"},"mp_2":{"title":"Collect only valid student records"},"mp_3":{"title":"Write the cleaned CSV file"},"mp_4":{"title":"Verify the saved clean CSV"}},"quiz":{"mp-1-read-student-file":{"title":"Build the cleaning helper","prompt":"Start from the CSV preview. Create a sibling helper file named `cleaning.py` and define `clean_row(row)` there. In `main.py`, import it with `from cleaning import clean_row`. Clean the name with whitespace trimming followed by title-case normalization and the score text with `strip()`. Return `None` for an empty cleaned name, invalid integer score text, or a score outside 0 through 100. Otherwise return `{\"name\": name, \"score\": score}`. Then print `clean_row(row)` for every imported row so you can inspect which rows are accepted or rejected.","hint":"Put the reusable row-cleaning function in `cleaning.py`; keep CSV orchestration in `main.py` and import the helper directly.","help":{"concept":"The helper should produce one dependable result: a cleaned dictionary for valid input or `None` for rejected input.","hint_1":"Check `name == \"\"` before attempting the score conversion.","hint_2":"Catch exactly `ValueError`, then apply the 0-through-100 range check."},"starterCode":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n"},"output_clean_students_csv":{"content":"old export\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Use the explicitly requested dictionary field `name`."},"2":{"message":"Use the explicitly requested dictionary field `score`."},"3":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"4":{"message":"Use `title()` because that method is explicitly required by the prompt."},"5":{"message":"Import `clean_row` from the sibling `cleaning.py` helper as the project requires."}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"mp-2-clean-one-row":{"title":"Collect only valid student records","prompt":"Keep `clean_row(row)` exactly as it works now. Replace the row-by-row preview with a `records` list. Loop through `csv.DictReader`, call `clean_row(row)` once per row, and append only results that are not `None`. Print `records` after the loop. Keep `clean_row(row)` in the sibling `cleaning.py` file and keep importing it into `main.py`; do not copy the helper back into the entry file.","hint":"The cleaner already decides whether a row is valid; this step should only collect accepted results.","help":{"concept":"Separating row validation from record collection keeps each responsibility small and reusable.","hint_1":"Store the helper result in `record` instead of calling the function several times.","hint_2":"Append only when `record is not None`."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","sourceChecks":{"0":{"message":"Use a `for` loop as the prompt requests."},"1":{"message":"Call `clean_row(...)` because that function call is explicitly required by the prompt."},"2":{"message":"Print the completed `records` list itself after the collection loop."},"3":{"message":"Keep the required `clean_row(row)` function in `cleaning.py`."}}},"mp-3-skip-bad-rows":{"title":"Write the cleaned CSV file","prompt":"Keep the valid-record builder. Replace the list preview with a deliverable file. Open `output/clean_students.csv` in write mode, write the header `name,score`, then write one cleaned `name,score` line for every record. Finally print `Wrote <count> clean records`. The supplied output file contains old text so write mode must replace it. Keep `clean_row(row)` in the sibling `cleaning.py` file and keep importing it into `main.py`; do not copy the helper back into the entry file.","hint":"Use the `records` list as the source for the final file instead of cleaning the CSV a second time.","help":{"concept":"Write mode should replace the old export, then one `file.write(...)` call can write each cleaned record.","hint_1":"Write the header first: `name,score\\n`.","hint_2":"Loop through `records` and write each name and numeric score on one line."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Keep the required `clean_row(row)` function in `cleaning.py`."}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n"},"mp-4-write-clean-records":{"title":"Verify the saved clean CSV","prompt":"Keep the working cleaner and output writer. After the completion message, reopen `output/clean_students.csv` in read mode and print exactly what was saved. The final output should show the completion message followed by the header and the three accepted records. Keep `clean_row(row)` in the sibling `cleaning.py` file and keep importing it into `main.py`; do not copy the helper back into the entry file.","hint":"The saved file is the deliverable, so verify the artifact itself instead of trusting only the in-memory list.","help":{"concept":"Reopen the same path after the write block has finished.","hint_1":"Print `file.read()` with `end=\"\"` so the file contents appear exactly as saved.","hint_2":"The output file should contain only the header and accepted cleaned rows."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n\nwith open(\"output/clean_students.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Keep the required `clean_row(row)` function in `cleaning.py`."}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n\nwith open(\"output/clean_students.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"try-module-7-clean-student-records-sketch0":{"title":"Inspect the student export","prompt":"Open `data/students.csv` in read mode with `csv.DictReader`. Loop through every row and print `name:score` using the named CSV columns. Do not clean or reject anything yet; this preview is only for seeing the imported data.","hint":"Start with the file exactly as it arrived so you can see which rows need cleaning.","help":{"concept":"A data-cleaning project begins by reading the real source file and understanding its shape before transforming it.","hint_1":"Create `reader = csv.DictReader(file)` inside the open-file block.","hint_2":"Loop through `reader` and use `row[\"name\"]` and `row[\"score\"]` rather than hard-coded output."},"starterCode":"import csv\n\n# Open data/students.csv in read mode.\n# Use csv.DictReader and print each row as name:score.\n","solutionCode":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n","sourceChecks":{"0":{"message":"Use the requested import involving `csv`."},"1":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"2":{"message":"Use a `for` loop as the prompt requests."},"3":{"message":"Title-case the student name."}},"starterFiles":{"main_py":{"content":"import csv\n\n# Open data/students.csv in read mode.\n# Use csv.DictReader and print each row as name:score.\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"}}}},"tryIt":{"try_module_7_clean_student_records_sketch0":{"title":"Try it yourself","prompt":"Inspect the student export with `csv.DictReader` before the project starts."},"allowReveal":true}},"reading-text-files":{"label":"Reading Text Files","summary":"Open existing text files with `with open(..., \"r\")`, read a whole file with `.read()` or process it one line at a time, and use relative paths for files inside the workspace.","cards":{"sketch0":{"title":"Open and read a whole text file"},"sketch1":{"title":"Process a file one line at a time"},"sketch2":{"title":"Read a file from a relative path"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-read-mode":{"title":"Read mode","prompt":"Which file mode is used to open a text file for reading?","hint":"Use the question wording and the lesson example to narrow the choices.","help":{"concept":"This question checks a specific idea from the lesson, not general test-taking strategy.","hint_1":"Compare each option to the exact topic named in the question.","hint_2":"Remove options that do not match the concept or evidence named in the question."},"options":{"a":"r","b":"w","c":"a","d":"x"}},"sc-relative-path":{"title":"Relative path example","prompt":"Which path correctly refers to a file named `story.txt` inside a folder named `data`?","hint":"Use the folder name, then the file name.","help":{"concept":"A relative path describes a file's location from the current workspace location using folder names separated by `/`.","hint_1":"The folder should come before the file name.","hint_2":"Choose the option that looks like folder slash file."},"options":{"a":"story.txt/data","b":"data/story.txt","c":"/data/story.txt","d":"data-story.txt"}},"mc-with-open-benefits":{"title":"Why use with open","prompt":"Choose all true statements about using `with open(...) as file:` when reading text files.","hint":"Think about what `with` does for the file resource and how you access the file inside the block.","help":{"concept":"`with open(...) as file:` creates a managed file block. You use the file variable inside the block, and Python handles closing the file afterward.","hint_1":"Look for statements about automatic closing and using the variable after `as`.","hint_2":"Two statements are correct: one about cleanup and one about the file variable name."},"options":{"a":"It helps make sure the file is closed after the block ends.","b":"It creates a variable like `file` that you can call `.read()` on.","c":"It always writes new text into the file before reading.","d":"It only works for files in the same folder, not nested folders."}},"mc-read-methods":{"title":"Reading methods","prompt":"Choose all statements that are true about `read()` and `readlines()`.","hint":"One returns a single string, and the other returns a list of lines.","help":{"concept":"`read()` gets the whole file as one string, while `readlines()` returns a list where each item is a line, often including newline characters.","hint_1":"Look for the options describing one big string and a list of lines.","hint_2":"Two options are correct: one mentions a single string, and one mentions newline characters in line items."},"options":{"a":"`read()` can return the whole file as one string.","b":"`readlines()` returns a list of lines.","c":"`read()` always removes every newline character automatically.","d":"`readlines()` returns one number for each line."}},"dr-read-file-steps":{"title":"Order the reading steps","prompt":"Put these steps in the correct order for reading and printing a file's contents.","hint":"Start by opening the file, then read, then print.","help":{"concept":"A basic file-reading flow is: open the file, read its contents into a variable, then use that value such as by printing it.","hint_1":"The file must be opened before `.read()` can be used.","hint_2":"After reading into a variable, the last step is showing the result in the output panel."},"tokens":{"t1":"Open the file with `with open(..., \"r\") as file:`","t2":"Read the text with `file.read()`","t3":"Store the result in a variable","t4":"Print the variable"}},"dr-build-path":{"title":"Build a relative path","prompt":"Arrange the tokens to make the relative path to `report.txt` inside the `data` folder.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"data","t2":"/","t3":"report.txt"}},"fb-read-call":{"title":"Complete the read call","prompt":"Fill in the missing method name to read all text from an open file.","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"template":"text = file.[blank1]()","choices":["read","write","close","open"]},"fb-open-mode":{"title":"Complete the open mode","prompt":"Fill in the missing mode so the file is opened for reading.","hint":"Focus on the missing concept rather than the exact missing term.","help":{"concept":"The blank should be completed with the term that fits the job being described.","hint_1":"Think about what the missing part needs to do in the statement.","hint_2":"Choose the term that best completes the meaning of the statement."},"template":"with open(\"notes.txt\", \"[blank1]\") as file:","choices":["r","w","a","x"]},"ci-read-and-print":{"title":"Print a file's contents","prompt":"Open `data/message.txt`, read the file's contents, and print the text you find there.\n\nYour output should be exactly:\n`Hello from file reading!`.","hint":"Read the task \"Print a file's contents\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/message.txt\", \"r\") as file:\n # read the file and print its contents\n pass","solutionCode":"with open(\"data/message.txt\", \"r\") as file:\n text = file.read()\n print(text)","sourceChecks":{"0":{"message":"Open data/message.txt to read the file."}}},"ci-first-line":{"title":"Print only the first line","prompt":"Open `data/notes.txt`, read only the first line, and print it without the ending newline character.\n\nYour output should be exactly:\n`Apples`.","hint":"Read the task \"Print only the first line\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/notes.txt\", \"r\") as file:\n # read the first line only\n # print it without the ending newline\n pass","solutionCode":"with open(\"data/notes.txt\", \"r\") as file:\n first = file.readline().rstrip(\"\\n\")\n print(first)","sourceChecks":{"0":{"message":"Open data/notes.txt to read the file."}}},"ci-count-lines":{"title":"Count lines in a text file","prompt":"Open `data/list.txt`, count how many lines are in the file, and print that number.\n\nYour output should be exactly:\n`3`.","hint":"Read the task \"Count lines in a text file\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/list.txt\", \"r\") as file:\n # count the lines and print the number\n pass","solutionCode":"with open(\"data/list.txt\", \"r\") as file:\n lines = file.readlines()\n print(len(lines))","sourceChecks":{"0":{"message":"Open data/list.txt to count the lines."}}},"try-reading-text-files-checkpoint":{"title":"Read a text file","prompt":"Read `data/note.txt` and print its contents without adding extra text.","hint":"Use `with open(\"data/note.txt\") as file:` and `file.read()`.","help":{"concept":"Open the file, read the text, and print exactly what was stored there.","hint_1":"Use `with open(\"data/note.txt\") as file:`.","hint_2":"Call `file.read()` and print the result without adding extra words."},"starterCode":"# Read data/note.txt and print its contents.\n","starterFiles":{"data_note_txt":{"content":"Hello from a file!\n"}},"solutionFiles":{"main_py":{"content":"with open(\"data/note.txt\") as file:\n print(file.read(), end=\"\")\n"},"data_note_txt":{"content":"Hello from a file!\n"}},"sourceChecks":{"0":{"message":"Open data/note.txt instead of typing the file contents."}},"solutionCode":"with open(\"data/note.txt\") as file:\n print(file.read(), end=\"\")\n"},"try-reading-text-files-sketch0":{"title":"Read the whole message file","prompt":"Open `message.txt` in read mode. Read all of its text into a variable named `message`, then print `message`. Print only the text that came from the file. Read the entire file with the `read()` method, store the returned text in a variable named `message`, and print that variable. Do not hard-code the file contents.","hint":"Use `with open(\"message.txt\", \"r\") as file:` and `message = file.read()`.","help":{"concept":"Use `.read()` when you want the complete text file as one string.","hint_1":"Store the result of `file.read()` in `message`.","hint_2":"Print the variable instead of typing the file's contents into your program."},"starterCode":"# Open message.txt in read mode.\n# Read all of its text into message, then print message.\n","starterFiles":{"note_txt":{"content":"Hello from a file\n"},"main_py":{"content":"# Open message.txt in read mode.\n# Read all of its text into message, then print message.\n"},"message_txt":{"content":"Keep learning."}},"solutionFiles":{"main_py":{"content":"with open(\"message.txt\", \"r\") as file:\n message = file.read()\n\nprint(message)\n"},"note_txt":{"content":"Hello from a file\n"},"message_txt":{"content":"Keep learning."}},"sourceChecks":{"0":{"message":"Read from the supplied `message.txt` file."},"1":{"message":"Use `read()` to obtain the file's text."},"2":{"message":"Store the result of `file.read()` in the explicitly requested variable `message`."},"3":{"message":"Print the `message` variable itself after reading the file into it."}},"solutionCode":"with open(\"message.txt\", \"r\") as file:\n message = file.read()\n\nprint(message)\n"},"try-reading-text-files-sketch1":{"title":"Process names one line at a time","prompt":"Open `names.txt` in read mode. Loop directly through the open file with a `for` loop that iterates directly over the opened file object and print each name with surrounding whitespace removed.","hint":"Inside the `with` block, use `for line in file:` and `print(line.strip())`.","help":{"concept":"Iterating over an open file lets you process one line at a time without first reading the whole file into one string.","hint_1":"The loop iterable should be the open variable `file`.","hint_2":"Use `line.strip()` before printing so the stored newline does not create extra blank lines."},"starterCode":"# Open names.txt in read mode.\n# Loop through the open file and print each stripped line.\n","starterFiles":{"names_txt":{"content":" Ava \nMia\n Noah\n"},"main_py":{"content":"# Open names.txt in read mode.\n# Loop through the open file and print each stripped line.\n"}},"solutionFiles":{"main_py":{"content":"with open(\"names.txt\", \"r\") as file:\n for line in file:\n print(line.strip())\n"},"names_txt":{"content":" Ava \nMia\n Noah\n"}},"sourceChecks":{"0":{"message":"Use a `for` loop over `file` as the prompt requests."}},"solutionCode":"with open(\"names.txt\", \"r\") as file:\n for line in file:\n print(line.strip())\n"},"try-reading-text-files-sketch2":{"title":"Read and clean text from a data folder","prompt":"The file `data/city.txt` contains one city name with inconsistent spaces and capitalization. Open that relative path in read mode, read the file text, remove surrounding whitespace, convert it to title case, and print the cleaned city name. Read the text from `data/city.txt`, remove surrounding whitespace with `strip()`, then convert the cleaned city text to title case with `title()`. Do not hard-code the cleaned city name.","hint":"Open `data/city.txt`, then use `.read().strip().title()` on the open file.","help":{"concept":"A relative path can point to a file inside a workspace folder, and the string returned by `.read()` can be processed like any other string.","hint_1":"The path is exactly `data/city.txt`.","hint_2":"Read the text first, then apply `.strip()` and `.title()` before printing."},"starterCode":"# Read data/city.txt in read mode.\n# Clean the file text with strip() and title(), then print it.\n","starterFiles":{"names_txt":{"content":"Ava\nMia\n"},"main_py":{"content":"# Read data/city.txt in read mode.\n# Clean the file text with strip() and title(), then print it.\n"},"data_city_txt":{"content":" seAttle \n"}},"solutionFiles":{"main_py":{"content":"with open(\"data/city.txt\", \"r\") as file:\n city = file.read().strip().title()\n\nprint(city)\n"},"names_txt":{"content":"Ava\nMia\n"},"data_city_txt":{"content":" seAttle \n"}},"sourceChecks":{"0":{"message":"Open the supplied relative path `data/city.txt`."},"1":{"message":"Read the city text from the file with `read()`."},"2":{"message":"Remove surrounding whitespace with `strip()`."},"3":{"message":"Convert the cleaned city text to title case with `title()`."}},"solutionCode":"with open(\"data/city.txt\", \"r\") as file:\n city = file.read().strip().title()\n\nprint(city)\n"},"sc-open-read":{"title":"Open a nested file for reading","prompt":"Which line safely opens `data/story.txt` for reading and gives the open file the name `file`?","hint":"Use a `with` block, the relative path, and read mode `r`.","help":{"concept":"`with open(path, \"r\") as file:` opens an existing text file for reading and closes it automatically when the block ends.","hint_1":"The relative path keeps the folder before the file name: `data/story.txt`.","hint_2":"Read mode is written as `\"r\"`."},"options":{"a":"with open(\"data/story.txt\", \"r\") as file:","b":"with open(\"story.txt/data\", \"w\") as file:","c":"open.read(\"data/story.txt\") as file:","d":"with read(\"data/story.txt\") as file:"}},"sc-read-all":{"title":"What .read() returns","prompt":"What does `file.read()` give you when `file` is an open text file?","hint":"Think about reading the complete contents at once.","help":{"concept":"For a text file, `.read()` returns the remaining file contents as one string.","hint_1":"It does not return one number per line.","hint_2":"Choose the option describing one string containing the file text."},"options":{"a":"One string containing the remaining text","b":"A new file on disk","c":"Only the file name","d":"The number of lines in the file"}},"sc-line-loop":{"title":"Read one line at a time","prompt":"Which pattern processes an open text file one line at a time?","hint":"An open file can be used directly in a `for` loop.","help":{"concept":"`for line in file:` gives the loop one line from the open file at a time.","hint_1":"You do not need `.read()` when you want to iterate through the file directly.","hint_2":"Look for the `for line in file:` pattern."},"options":{"a":"for line in file:","b":"for file in line:","c":"line = file.read()","d":"while file = line:"}},"sc-with-cleanup":{"title":"Why use with open","prompt":"What happens to the file when execution leaves a `with open(...) as file:` block?","hint":"The `with` statement manages the file resource for you.","help":{"concept":"The `with` statement closes the file automatically when the block ends, even though you did not call `file.close()` yourself.","hint_1":"The file is not deleted or rewritten.","hint_2":"The managed file is closed after the block."},"options":{"a":"Python closes the file automatically","b":"Python deletes the file","c":"Python changes the file to write mode","d":"Python keeps the file open forever"}}},"tryIt":{"try_reading_text_files_checkpoint":{"title":"Try it yourself","prompt":"Read `data/note.txt` and print its contents without adding extra text."},"try_reading_text_files_sketch0":{"title":"Try it yourself","prompt":"Open `message.txt` in read mode. Read all of its text into a variable named `message`, then print `message`. Print only the text that came from the file. Read the entire file with the `read()` method, store the returned text in a variable named `message`, and print that variable. Do not hard-code the file contents."},"try_reading_text_files_sketch1":{"title":"Try it yourself","prompt":"Open `names.txt` in read mode. Loop directly through the open file with a `for` loop that iterates directly over the opened file object and print each name with surrounding whitespace removed."},"try_reading_text_files_sketch2":{"title":"Try it yourself","prompt":"The file `data/city.txt` contains one city name with inconsistent spaces and capitalization. Open that relative path in read mode, read the file text, remove surrounding whitespace, convert it to title case, and print the cleaned city name. Read the text from `data/city.txt`, remove surrounding whitespace with `strip()`, then convert the cleaned city text to title case with `title()`. Do not hard-code the cleaned city name."},"allowReveal":true}},"simple-csv-processing":{"label":"Simple CSV Processing","summary":"Read CSV files with `csv.DictReader`, access values by header name, clean and convert row values, and keep valid rows moving through a simple processing loop.","cards":{"sketch0":{"title":"Read CSV rows by column name"},"sketch1":{"title":"Clean and convert CSV values"},"sketch2":{"title":"Process valid rows and reject bad data safely"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-import-csv":{"title":"Why import csv?","prompt":"Why do you write `import csv` before using `csv.DictReader`?","hint":"Think about where `DictReader` comes from.","help":{"concept":"`DictReader` is part of Python's standard library `csv` module, so the module must be imported before you can use `csv.DictReader`.","hint_1":"Look for the choice that says the code is making CSV tools available from a module.","hint_2":"Without the import, Python does not know what `csv` refers to."},"options":{"a":"It makes the `csv` module available so you can use `csv.DictReader`.","b":"It automatically cleans spaces from every CSV value.","c":"It turns every CSV value into an integer.","d":"It creates a new CSV file if one does not exist."}},"sc-dictreader-row-type":{"title":"What does DictReader produce?","prompt":"When you loop through `csv.DictReader(file)`, what is each `row` most like?","hint":"Think about accessing values with column names like `row[\"name\"]`.","help":{"concept":"`csv.DictReader` uses the header row as keys, so each row behaves like a dictionary mapping column names to text values.","hint_1":"If you can use a column name inside square brackets, the row is key-based.","hint_2":"The header labels become keys such as `name` and `score`."},"options":{"a":"A dictionary that maps column names to values","b":"A single integer from the row","c":"A list of file names","d":"A function that cleans the row"}},"mc-clean-score-steps":{"title":"Clean a score value","prompt":"A CSV row has `row[\"score\"] == \" 12 \"`. Which steps correctly prepare it for math? Choose all that apply.","hint":"You need a number, not spaced text.","help":{"concept":"CSV values are read as strings. To use a numeric field in math, remove extra spaces if needed and convert the cleaned text to an integer.","hint_1":"One correct step removes surrounding spaces, and another converts text to a number.","hint_2":"Methods like `.strip()` clean text, while `int(...)` changes the type."},"options":{"a":"Use `.strip()` on the score text","b":"Use `int(...)` on the cleaned score text","c":"Leave it as text and add 1 directly","d":"Use `dict(row)` to turn the score into a number"}},"mc-good-csv-processing":{"title":"Useful CSV processing patterns","prompt":"Which snippets are good beginner patterns for simple CSV processing? Choose all that apply.","hint":"Look for patterns that use the csv module and column names clearly.","help":{"concept":"Good beginner CSV processing uses `import csv`, `csv.DictReader`, and clear access by header names. Printing `dict(row)` is also useful for inspecting a row safely.","hint_1":"One correct option reads rows with `csv.DictReader`, and another prints a full row dictionary for inspection.","hint_2":"Avoid choices that claim CSV values become numbers automatically or that skip importing the module."},"options":{"a":"`import csv` followed by `reader = csv.DictReader(file)`","b":"`print(dict(row))` inside a loop to inspect each row","c":"Using `row[\"score\"]` to access a named column","d":"Assuming `row[\"score\"]` is already an integer without conversion"}},"dr-read-csv-order":{"title":"Order the CSV reading steps","prompt":"Put these steps in the correct order for reading a CSV file with `DictReader` and printing one column.","hint":"Start by making the csv tools available, then open the file, then create the reader.","help":{"concept":"A CSV-reading script usually follows a sequence: import the module, open the file, create a `DictReader`, loop through rows, then access values by column name.","hint_1":"The loop happens after the reader is created.","hint_2":"Accessing `row[\"name\"]` must happen inside the loop, after a row exists."},"tokens":{"t1":"print(row[\"name\"])","t2":": for row in reader","t3":"reader = csv.DictReader(file)","t4":"with open(\"names.csv\") as file","t5":"import csv"}},"dr-clean-row-order":{"title":"Order the row-cleaning steps","prompt":"Arrange these actions in the order that cleans a score and then uses it in math.","hint":"Get the text first, clean it, convert it, then calculate.","help":{"concept":"When cleaning numeric CSV data, first read the text value, then strip spaces, then convert to `int`, and only after that use it in arithmetic.","hint_1":"Arithmetic should happen after conversion to an integer.","hint_2":"`.strip()` belongs before `int(...)`, because it cleans the text that `int` will read."},"tokens":{"t1":"add 1 to the integer score","t2":"convert the cleaned text with `int(...)`","t3":"read `row[\"score\"]`","t4":"remove spaces with `.strip()`"}},"fb-dictreader-name":{"title":"Choose the CSV reader tool","prompt":"Complete the code so rows can be accessed by column name.","hint":"Use the csv tool that creates dictionary-like rows.","help":{"concept":"Choose the csv reader that uses the header row as dictionary keys for every later record.","hint_1":"The missing value is the reader class name after `csv.`.","hint_2":"It is not `reader` or `split`; it is the CSV helper that starts with `Dict`."},"template":"reader = csv.[blank1](file)","choices":["DictReader","reader","split","Writer"]},"fb-strip-choice":{"title":"Choose the cleaning method","prompt":"Fill in the missing method to remove spaces around a CSV value.","hint":"This string method removes spaces from both ends.","help":{"concept":"Choose the string-cleaning method that removes whitespace from both ends before conversion.","hint_1":"The missing method is called on a string like `row[\"name\"]`.","hint_2":"It is the method that turns `\" Ava \"` into `\"Ava\"`."},"template":"clean_name = row[\"name\"].[blank1]()","choices":["strip","append","write","read"]},"ci-print-clean-names":{"title":"Print cleaned names from a CSV file","prompt":"Read `students.csv` with `csv.DictReader`, clean each name as you loop through the rows, and print the cleaned names.\n\nYour output should be exactly:\n`Ava`\n`Ben`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"import csv\n\nwith open(\"students.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n # print the cleaned name\n pass","solutionCode":"import csv\n\nwith open(\"students.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"].strip())","sourceChecks":{"0":{"message":"Strip each CSV name before printing it."}}},"ci-sum-valid-scores":{"title":"Sum valid scores from CSV","prompt":"Read `scores.csv`, clean each score, try to convert it to an integer, and add only the valid numbers to `total`. Print `total` after the loop.\n\nYour output should be exactly:\n`16`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"import csv\n\ntotal = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n # try to convert the cleaned score and add it to total\n pass\n\nprint(total)","solutionCode":"import csv\n\ntotal = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n try:\n total += int(row[\"score\"].strip())\n except ValueError:\n pass\n\nprint(total)","sourceChecks":{"0":{"message":"Use try/except for invalid score values."},"1":{"message":"Convert score text with int()."}}},"ci-write-summary-file":{"title":"Write a CSV summary file","prompt":"Build a short report from `scores.csv`. As you loop, update `valid_rows` and `total_score` for rows with valid integer scores, then write those results to `summary.txt` and print the file contents.\n\nYour output should be exactly:\n`valid_rows: 2`\n`total_score: 16`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"import csv\n\nvalid_rows = 0\ntotal_score = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n # update valid_rows and total_score for rows with valid integer scores\n pass\n\n# write summary.txt, then print its contents","solutionCode":"import csv\n\nvalid_rows = 0\ntotal_score = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n try:\n score = int(row[\"score\"].strip())\n valid_rows += 1\n total_score += score\n except ValueError:\n pass\n\nwith open(\"summary.txt\", \"w\") as file:\n file.write(f\"valid_rows: {valid_rows}\\n\")\n file.write(f\"total_score: {total_score}\\n\")\n\nwith open(\"summary.txt\") as file:\n print(file.read(), end=\"\")","sourceChecks":{"0":{"message":"Use try/except for invalid score values."},"1":{"message":"Write the summary to summary.txt."}}},"try-simple-csv-processing-checkpoint":{"title":"Read the first CSV row","prompt":"Open `scores.csv` with `csv.DictReader`, read the first row, and print the name on one line and the score on the next line.","hint":"Import `csv`, create `csv.DictReader(file)`, then use the first row.","help":{"concept":"This card starts the lesson with a real CSV file instead of a hard-coded string row.","hint_1":"Use `import csv` and `with open(\"scores.csv\") as file:`.","hint_2":"Create `reader = csv.DictReader(file)`, get the first row, and print `row[\"name\"]` and `row[\"score\"]`."},"starterCode":"import csv\n\n# Open scores.csv with csv.DictReader.\n# Print the first row name, then the first row score.\n","solutionCode":"import csv\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n row = next(reader)\n print(row[\"name\"])\n print(row[\"score\"])\n","sourceChecks":{"0":{"message":"Use csv.DictReader to read scores.csv."},"1":{"message":"Open scores.csv for this step."}}},"try-simple-csv-processing-sketch0":{"title":"Read rows by header name","prompt":"Read a CSV filename from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Open that file in read mode, create a `csv.DictReader` created for the opened file, loop through every row, and print each row as `name:score` using `row[\"name\"]` and `row[\"score\"]`. The workspace provides `data/class_a.csv` and `data/class_b.csv`.","hint":"Use the CSV header names instead of splitting each line manually.","help":{"concept":"`csv.DictReader` turns each data row into a dictionary-like object whose keys come from the header row.","hint_1":"Create `reader = csv.DictReader(file)` inside the open-file block.","hint_2":"Use a `for row in reader:` loop and access both named columns from `row`."},"starterCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Open path in read mode with csv.DictReader.\n# Loop through every row and print name:score using the named columns.\n","solutionCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use a `for` loop as the prompt requests."},"2":{"message":"Use the explicitly requested dictionary field `name`."},"3":{"message":"Use the explicitly requested dictionary field `score`."}},"starterFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Open path in read mode with csv.DictReader.\n# Loop through every row and print name:score using the named columns.\n"},"data_class_a_csv":{"content":"name,score\nAva,92\nBen,85\n"},"data_class_b_csv":{"content":"name,score\nMia,78\nNoah,88\nLiam,91\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n"},"data_class_a_csv":{"content":"name,score\nAva,92\nBen,85\n"},"data_class_b_csv":{"content":"name,score\nMia,78\nNoah,88\nLiam,91\n"}}},"try-simple-csv-processing-sketch1":{"title":"Clean and convert CSV fields","prompt":"Read a CSV filename from input. Open `data/<filename>` with `csv.DictReader`. For every row, clean the name with whitespace trimming followed by title-case normalization, clean and convert the score with integer conversion of the `score` field after removing its surrounding whitespace, then print `Name:score`. The supplied files contain valid numeric score text with inconsistent whitespace and capitalization.","hint":"CSV field values are strings, so clean the text before converting the score.","help":{"concept":"This step combines named-column access with the cleaning and integer-conversion skills you already know.","hint_1":"Store a cleaned `name` and numeric `score` inside the row loop.","hint_2":"Do not hard-code the displayed names or scores; use the values from each CSV row."},"starterCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Read every row with csv.DictReader.\n# Clean the name with strip().title(), convert the cleaned score with int(),\n# and print Name:score for each row.\n","solutionCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score = int(row[\"score\"].strip())\n print(name + \":\" + str(score))\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use the explicitly requested dictionary field `score`."},"2":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"3":{"message":"Use `title()` because that method is explicitly required by the prompt."},"4":{"message":"Call `int(...)` because that function call is explicitly required by the prompt."}},"starterFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Read every row with csv.DictReader.\n# Clean the name with strip().title(), convert the cleaned score with int(),\n# and print Name:score for each row.\n"},"data_clean_a_csv":{"content":"name,score\n aVA , 92 \n ben lee , 85\n"},"data_clean_b_csv":{"content":"name,score\n mIA , 70 \n NOAH , 100 \n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score = int(row[\"score\"].strip())\n print(name + \":\" + str(score))\n"},"data_clean_a_csv":{"content":"name,score\n aVA , 92 \n ben lee , 85\n"},"data_clean_b_csv":{"content":"name,score\n mIA , 70 \n NOAH , 100 \n"}}},"try-simple-csv-processing-sketch2":{"title":"Summarize only valid CSV rows","prompt":"Read a CSV filename from input and process `data/<filename>` with `csv.DictReader`. Clean each name and score field. Count and sum only rows whose cleaned name is not empty and whose score converts to an integer from 0 through 100. After the loop, print exactly `valid_rows: <count>` and `total_score: <sum>`. Invalid rows should not stop later rows from being processed.","hint":"Apply the 7.5 validation rules inside the CSV row loop.","help":{"concept":"A CSV row is accepted only after the name, conversion, and range checks all succeed.","hint_1":"Catch exactly `ValueError` and set `score = None` so invalid numeric text has an explicit rejection value.","hint_2":"Increment `valid_rows` and `total_score` only inside the valid 0-through-100 branch."},"starterCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\n# Read every CSV row.\n# Clean the name and score text.\n# Count and sum only rows with a non-empty name and an integer score from 0..100.\n# Print valid_rows and total_score after the loop.\n","solutionCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name != \"\":\n try:\n score = int(score_text)\n except ValueError:\n score = None\n\n if score is not None and 0 <= score <= 100:\n valid_rows += 1\n total_score += score\n\nprint(\"valid_rows: \" + str(valid_rows))\nprint(\"total_score: \" + str(total_score))\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Loop through the CSV rows instead of hard-coding the total."},"2":{"message":"Convert the score text with int()."},"3":{"message":"Add each numeric score into total."}},"starterFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\n# Read every CSV row.\n# Clean the name and score text.\n# Count and sum only rows with a non-empty name and an integer score from 0..100.\n# Print valid_rows and total_score after the loop.\n"},"data_mixed_a_csv":{"content":"name,score\n Ava ,92\n ,75\nLeo,ten\nMia,105\nNoah,80\n"},"data_mixed_b_csv":{"content":"name,score\n kai ,0\nLena,100\nOmar,-2\nIvy,55\nNia,oops\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name != \"\":\n try:\n score = int(score_text)\n except ValueError:\n score = None\n\n if score is not None and 0 <= score <= 100:\n valid_rows += 1\n total_score += score\n\nprint(\"valid_rows: \" + str(valid_rows))\nprint(\"total_score: \" + str(total_score))\n"},"data_mixed_a_csv":{"content":"name,score\n Ava ,92\n ,75\nLeo,ten\nMia,105\nNoah,80\n"},"data_mixed_b_csv":{"content":"name,score\n kai ,0\nLena,100\nOmar,-2\nIvy,55\nNia,oops\n"}}},"sc-dictreader-purpose":{"title":"Why use DictReader?","prompt":"What is the main beginner benefit of `csv.DictReader(file)` when the CSV has a header row such as `name,score`?","hint":"Think about how you access `row[\"name\"]`.","help":{"concept":"`csv.DictReader` uses the header row as keys, so later rows can be accessed by meaningful column names.","hint_1":"The header labels become names such as `name` and `score`.","hint_2":"Choose the answer about dictionary-like rows and named columns."},"options":{"a":"Each row can be accessed with keys such as `row[\"name\"]` and `row[\"score\"]`","b":"Every value is automatically converted to an integer","c":"The CSV file is rewritten with cleaner spacing","d":"The header row is deleted from disk"}},"sc-csv-value-type":{"title":"CSV values start as text","prompt":"If a CSV row contains `Ava,92`, what kind of value is `row[\"score\"]` when it first comes from `csv.DictReader`?","hint":"Reading CSV data does not automatically perform numeric conversion.","help":{"concept":"`csv.DictReader` reads field values as strings. Numeric-looking text must still be converted before numeric calculations.","hint_1":"The characters `92` came from a text file.","hint_2":"Choose the string value rather than the integer value."},"options":{"a":"The string `\"92\"`","b":"The integer `92`","c":"The float `92.0`","d":"A dictionary containing only the score"}},"sc-clean-convert-order":{"title":"Clean before numeric conversion","prompt":"A CSV score field is `\" 92 \"`. Which expression correctly removes surrounding spaces and converts it to an integer?","hint":"Clean the string first, then pass the cleaned text to `int(...)`.","help":{"concept":"CSV values are strings, so a common numeric-field pattern is `int(row[\"score\"].strip())`.","hint_1":"`.strip()` removes surrounding whitespace.","hint_2":"`int(...)` performs the numeric conversion after cleaning."},"options":{"a":"int(row[\"score\"].strip())","b":"row[\"score\"].int().strip()","c":"row[\"score\"] + 1","d":"csv.int(row[\"score\"])"}},"sc-bad-row-policy":{"title":"Reject one bad row without stopping later rows","prompt":"While processing many CSV rows, one cleaned score contains `\"oops\"`. What beginner pattern lets the program reject that row and continue processing later rows?","hint":"Use the specific conversion exception from the previous topics.","help":{"concept":"Catch `ValueError` around the integer conversion for that row, then continue the surrounding row-processing logic.","hint_1":"The problem is invalid integer text, not a missing file.","hint_2":"Choose the pattern that handles `ValueError` rather than crashing the whole CSV loop."},"options":{"a":"Use `try` around `int(...)` and catch `ValueError` for that row","b":"Assume every score is already valid","c":"Catch `FileNotFoundError` around the integer conversion","d":"Convert every bad score to 0 automatically"}}},"tryIt":{"try_simple_csv_processing_checkpoint":{"title":"Try it yourself","prompt":"Open `scores.csv` with `csv.DictReader`, read the first row, and print the name on one line and the score on the next line."},"try_simple_csv_processing_sketch0":{"title":"Try it yourself","prompt":"Read a CSV filename from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Open that file in read mode, create a `csv.DictReader` created for the opened file, loop through every row, and print each row as `name:score` using `row[\"name\"]` and `row[\"score\"]`. The workspace provides `data/class_a.csv` and `data/class_b.csv`."},"try_simple_csv_processing_sketch1":{"title":"Try it yourself","prompt":"Read a CSV filename from input. Open `data/<filename>` with `csv.DictReader`. For every row, clean the name with whitespace trimming followed by title-case normalization, clean and convert the score with integer conversion of the `score` field after removing its surrounding whitespace, then print `Name:score`. The supplied files contain valid numeric score text with inconsistent whitespace and capitalization."},"try_simple_csv_processing_sketch2":{"title":"Try it yourself","prompt":"Process only valid CSV rows and summarize the accepted scores."},"allowReveal":true}},"try-except-basics":{"label":"Try/Except Basics","summary":"Protect an operation that may fail with `try`, catch the specific expected exception, and keep the program usable with a clear fallback instead of a crash.","cards":{"sketch0":{"title":"Catch ValueError from a risky conversion"},"sketch1":{"title":"Catch FileNotFoundError when opening a path"},"sketch2":{"title":"Continue after a handled exception"},"quiz":{"title":"Check your understanding"}},"quiz":{"q1":{"title":"What happens after a caught conversion error?","prompt":"A program runs this pattern:\n\n```python\ntry:\n number = int(text)\nexcept ValueError:\n print(\"Bad number\")\n```\n\nIf `text` is `\"cat\"`, what happens?","hint":"Think about what `int()` does with text that is not a valid whole number.","help":{"concept":"`except ValueError` handles failures from `int()` when text cannot be converted to an integer.","hint_1":"`int(\"cat\")` cannot produce a number, so Python raises a `ValueError`.","hint_2":"Because that specific error is caught, the program runs the `except` block instead of stopping immediately."},"options":{"a":"The `except` block runs and prints `Bad number`","b":"The `try` block prints the converted number","c":"Python ignores the bad text and uses 0","d":"The program always stops before reaching `except`"}},"q2":{"title":"Which error fits int conversion?","prompt":"Which exception type should you catch when `int(user_text)` might fail because the text is not a valid integer?","hint":"Work through the operation in Python terms, then select the matching option.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"NameError","b":"ValueError","c":"IndexError","d":"SyntaxError"}},"q3":{"title":"Why use try/except here?","prompt":"Choose all true reasons to use `try/except` around `int(text)` when cleaning messy input.","hint":"Look for benefits related to handling bad numeric text safely.","help":{"concept":"`try/except` is useful when some values may be invalid and you want the program to respond safely instead of crashing.","hint_1":"Think about what happens when one item is bad in a larger set of inputs.","hint_2":"Correct choices should mention graceful handling and continued program flow, not guaranteed conversion success."},"options":{"a":"It lets the program handle invalid numeric text without crashing immediately","b":"It can show a fallback message when conversion fails","c":"It guarantees every string will become an integer","d":"It can help a loop continue processing later values after one bad value"}},"q4":{"title":"Which inputs would trigger ValueError?","prompt":"Choose all values that would raise `ValueError` in `int(value)`.","hint":"Pick the strings that are not valid whole-number text.","help":{"concept":"`int()` accepts strings like `\"12\"` or `\"-3\"`, but rejects text with letters or decimal points in string form for plain integer conversion.","hint_1":"A minus sign with digits is still a valid integer string.","hint_2":"Look for values containing letters or a decimal point as text."},"options":{"a":"\"18\"","b":"\"blue\"","c":"\"4.5\"","d":"\"-2\""}},"q5":{"title":"Order of execution when conversion fails","prompt":"Put these steps in the order they happen when `int(text)` raises `ValueError` inside a `try/except` block.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"Python enters the `try` block","t2":"`int(text)` raises `ValueError`","t3":"The rest of the `try` block is skipped","t4":"The matching `except` block runs"}},"q6":{"title":"Build a basic try/except pattern","prompt":"Arrange these code pieces into a correct basic pattern that converts input text to an integer and handles bad input.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"try:","t2":"number = int(text)","t3":"print(number)","t4":"except ValueError:","t5":"print(\"Invalid input\")"}},"q7":{"title":"Name the catching keyword","prompt":"Complete the code keyword that handles the error after `try`.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"try:\n number = int(text)\n[blank1] ValueError:\n print(\"Bad input\")","choices":["except","return","while","import"]},"q8":{"title":"Choose the risky conversion","prompt":"Fill in the expression that can raise `ValueError` when the text is not a valid integer.","hint":"Use the built-in conversion from text to integer.","help":{"concept":"The risky step in this pattern is converting text with `int(...)`, because some strings are not valid integers.","hint_1":"The missing code should attempt to turn `user_text` into a whole number.","hint_2":"Choose the expression that calls Python's integer conversion function on the variable."},"template":"try:\n number = [blank1]\n print(number)\nexcept ValueError:\n print(\"Invalid\")","choices":["int(user_text)","print(user_text)","len(user_text)","str(user_text)"]},"q9":{"title":"Catch a bad integer input","prompt":"A number scanner might receive invalid text. Convert the input inside a `try` block, then print either the formatted number or an invalid message.\n\nFor example, if the input is `27`, your program should print:\n`Number: 27`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"text = input()\n\n# Convert the text to an integer inside try.\n# Print either the converted result or an invalid message.","solutionCode":"text = input()\n\ntry:\n number = int(text)\n print(f\"Number: {number}\")\nexcept ValueError:\n print(\"Invalid number\")","sourceChecks":{"0":{"message":"Use a try block for the conversion."},"1":{"message":"Convert the text with int()."}}},"q10":{"title":"Add two inputs safely","prompt":"Two score entries arrive as text. Convert both values inside `try`, then print the sum or an invalid message if either value cannot be turned into an integer.\n\nFor example, if the inputs are `8` and `5`, your program should print:\n`Sum: 13`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"first_text = input()\nsecond_text = input()\n\n# Convert both values inside try.\n# Print the sum or an invalid message.","solutionCode":"first_text = input()\nsecond_text = input()\n\ntry:\n first_number = int(first_text)\n second_number = int(second_text)\n print(f\"Sum: {first_number + second_number}\")\nexcept ValueError:\n print(\"Invalid input\")","sourceChecks":{"0":{"message":"Use a try block for the conversion."},"1":{"message":"Convert the text with int()."}}},"q11":{"title":"Count valid numbers","prompt":"A comma-separated list may contain bad entries. Loop through each part, try to convert it to `int`, count only the valid integers, and print the final count.\n\nFor example, if the input is `3,7,bad,10`, your program should print:\n`Valid count: 3`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"parts = input().split(\",\")\nvalid_count = 0\n\n# Loop through each part.\n# Try to convert each one to int.\n# Count only the valid integers.\n# Print the final count.","solutionCode":"parts = input().split(\",\")\nvalid_count = 0\n\nfor part in parts:\n try:\n int(part)\n valid_count += 1\n except ValueError:\n pass\n\nprint(f\"Valid count: {valid_count}\")","sourceChecks":{"0":{"message":"Loop through each part."},"1":{"message":"Use try/except around the int conversion."},"2":{"message":"Convert each value with int()."}}},"try-try-except-basics-checkpoint":{"title":"Handle a bad number","prompt":"Read input and try to convert it to an integer. Print `Valid` if it works, otherwise print `Invalid`.","hint":"Use `try`, `except ValueError`.","help":{"concept":"A `try/except` block handles errors without crashing the program.","hint_1":"Use `try`, `except ValueError`.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"text = input()\n\n# Print Valid for an integer, otherwise Invalid.\n","solutionCode":"text = input()\ntry:\n int(text)\n print(\"Valid\")\nexcept ValueError:\n print(\"Invalid\")\n","sourceChecks":{"0":{"message":"Use a try block for the conversion."},"1":{"message":"Convert the text with int()."}}},"try-try-except-basics-sketch0":{"title":"Handle an invalid integer","prompt":"Read one line of text. Inside `try`, convert it with `int(text)` and print `Number: <value>`. Catch exactly `ValueError` and print `Invalid number` when conversion fails.","hint":"The conversion belongs inside `try`, and the handler should name `ValueError`.","help":{"concept":"`int(text)` can raise `ValueError`; catching that specific exception lets the program show a clear fallback instead of crashing.","hint_1":"Keep `number = int(text)` inside the `try` block.","hint_2":"Use `except ValueError:` followed by `print(\"Invalid number\")`."},"starterCode":"text = input().strip()\n\n# Convert text with int(...) inside try.\n# Print Number: <value> or Invalid number.\n","solutionCode":"text = input().strip()\n\ntry:\n number = int(text)\n print(\"Number: \" + str(number))\nexcept ValueError:\n print(\"Invalid number\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `int(...)` because that function call is explicitly required by the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"starterFiles":{"main_py":{"content":"text = input().strip()\n\n# Convert text with int(...) inside try.\n# Print Number: <value> or Invalid number.\n"}},"solutionFiles":{"main_py":{"content":"text = input().strip()\n\ntry:\n number = int(text)\n print(\"Number: \" + str(number))\nexcept ValueError:\n print(\"Invalid number\")\n"}}},"try-try-except-basics-sketch1":{"title":"Handle a missing data file","prompt":"Read a file name from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Try to open that path in read mode and print its stripped text. Catch exactly `FileNotFoundError` and print `Missing file` when the selected file does not exist. The workspace provides `data/note.txt`.","hint":"The risky operation is opening the selected path for reading.","help":{"concept":"A missing read path raises `FileNotFoundError`, which is different from the `ValueError` raised by a bad integer conversion.","hint_1":"Keep `with open(path, \"r\") as file:` inside `try`.","hint_2":"Use `except FileNotFoundError:` for the missing-file fallback."},"starterCode":"filename = input().strip()\npath = \"data/\" + filename\n\n# Try to open path in read mode and print its stripped text.\n# If the file is missing, print Missing file.\n","solutionCode":"filename = input().strip()\npath = \"data/\" + filename\n\ntry:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\nexcept FileNotFoundError:\n print(\"Missing file\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Convert the text with int()."}},"starterFiles":{"main_py":{"content":"filename = input().strip()\npath = \"data/\" + filename\n\n# Try to open path in read mode and print its stripped text.\n# If the file is missing, print Missing file.\n"},"data_note_txt":{"content":"Study exceptions carefully.\n"}},"solutionFiles":{"main_py":{"content":"filename = input().strip()\npath = \"data/\" + filename\n\ntry:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\nexcept FileNotFoundError:\n print(\"Missing file\")\n"},"data_note_txt":{"content":"Study exceptions carefully.\n"}}},"try-try-except-basics-sketch2":{"title":"Continue after one missing file","prompt":"Read two file names. Loop through `[first, second]`. For each name, try to open `data/<filename>` and print the stripped text. If that file is missing, catch exactly `FileNotFoundError`, print `Missing: <filename>`, and let the loop continue to the next name. The workspace provides `data/alpha.txt` and `data/beta.txt`.","hint":"Put the `try/except` inside the loop so one missing file does not stop the second attempt.","help":{"concept":"A handled exception ends that iteration's risky work, then normal loop execution continues with the next item.","hint_1":"Build `path = \"data/\" + filename` inside the loop.","hint_2":"Catch `FileNotFoundError` and print the missing filename instead of using `pass`."},"starterCode":"first = input().strip()\nsecond = input().strip()\n\n# Loop through [first, second].\n# For each filename, open data/<filename> and print its stripped text.\n# If that file is missing, print Missing: <filename> and continue.\n","solutionCode":"first = input().strip()\nsecond = input().strip()\n\nfor filename in [first, second]:\n path = \"data/\" + filename\n try:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\n except FileNotFoundError:\n print(\"Missing: \" + filename)\n","sourceChecks":{"0":{"message":"Use a `for` loop as the prompt requests."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Convert each value with int()."}},"starterFiles":{"main_py":{"content":"first = input().strip()\nsecond = input().strip()\n\n# Loop through [first, second].\n# For each filename, open data/<filename> and print its stripped text.\n# If that file is missing, print Missing: <filename> and continue.\n"},"data_alpha_txt":{"content":"Alpha file\n"},"data_beta_txt":{"content":"Beta file\n"}},"solutionFiles":{"main_py":{"content":"first = input().strip()\nsecond = input().strip()\n\nfor filename in [first, second]:\n path = \"data/\" + filename\n try:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\n except FileNotFoundError:\n print(\"Missing: \" + filename)\n"},"data_alpha_txt":{"content":"Alpha file\n"},"data_beta_txt":{"content":"Beta file\n"}}},"sc-value-error":{"title":"Match the conversion error","prompt":"Which exception should handle `int(text)` when `text` might contain something like `\"apple\"`?","hint":"An invalid value is being passed to a valid conversion function.","help":{"concept":"`int(...)` raises `ValueError` when the text cannot represent a whole number.","hint_1":"The function name `int` exists, so this is not a `NameError`.","hint_2":"Choose the exception for a value that cannot be converted."},"options":{"a":"ValueError","b":"FileNotFoundError","c":"NameError","d":"IndexError"}},"sc-file-not-found":{"title":"Match the missing-file error","prompt":"Which exception should handle `open(\"data/missing.txt\", \"r\")` when the file does not exist?","hint":"The path points to a file that Python cannot find.","help":{"concept":"Opening a missing path for reading raises `FileNotFoundError`.","hint_1":"This is a file-location problem, not an integer-conversion problem.","hint_2":"Choose the exception whose name describes a missing file."},"options":{"a":"FileNotFoundError","b":"ValueError","c":"TypeError","d":"IndexError"}},"sc-matching-handler":{"title":"What happens after an exception is caught","prompt":"When code inside `try` raises a `ValueError` and the program has `except ValueError:`, what happens next?","hint":"Python stops the remaining statements in that `try` block and jumps to the matching handler.","help":{"concept":"A matching `except` block handles the raised exception; statements after the failing line inside `try` are skipped.","hint_1":"Python does not continue the rest of the `try` block after the exception.","hint_2":"Choose the option where the matching `except` block runs."},"options":{"a":"Python runs the matching `except ValueError` block","b":"Python ignores the error and continues the next line inside `try`","c":"Python changes the bad value to 0","d":"Python always stops before checking `except`"}},"sc-specific-exception":{"title":"Why catch a specific exception","prompt":"Why is `except ValueError:` better here than a broad bare `except:` when the risky operation is `int(text)`?","hint":"Handle the error you expect instead of hiding unrelated problems.","help":{"concept":"Catching the specific expected exception makes the program's intent clearer and avoids silently swallowing unrelated bugs.","hint_1":"The known risk is an invalid integer value.","hint_2":"Choose the answer about handling that known error while leaving unrelated errors visible."},"options":{"a":"It handles the expected conversion error without hiding every unrelated exception","b":"It guarantees every string becomes an integer","c":"It makes `try` unnecessary","d":"It turns all exceptions into `ValueError`"}}},"tryIt":{"try_try_except_basics_checkpoint":{"title":"Try it yourself","prompt":"Read input and try to convert it to an integer. Print `Valid` if it works, otherwise print `Invalid`."},"try_try_except_basics_sketch0":{"title":"Try it yourself","prompt":"Convert user input safely with `except ValueError`."},"try_try_except_basics_sketch1":{"title":"Try it yourself","prompt":"Read a file name from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Try to open that path in read mode and print its stripped text. Catch exactly `FileNotFoundError` and print `Missing file` when the selected file does not exist. The workspace provides `data/note.txt`."},"try_try_except_basics_sketch2":{"title":"Try it yourself","prompt":"Keep processing a second file after the first filename is missing."},"allowReveal":true}},"validating-and-cleaning-input":{"label":"Validating and Cleaning Input","summary":"Clean raw text before using it, detect missing values after cleaning, validate integer ranges safely, and combine those rules in a reusable function.","cards":{"sketch0":{"title":"Clean text before validating it"},"sketch1":{"title":"Missing, invalid, and out-of-range values"},"sketch2":{"title":"Combine cleaning rules in a function"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-valid-row":{"title":"Which row is valid after cleaning?","prompt":"A program strips spaces from both fields, then requires a non-empty name and an age that can be converted with `int()`. Which row would be accepted?","hint":"Look for a row where spaces can be removed and the age text still becomes a whole number.","help":{"concept":"A row is valid only if cleaning with `strip()` leaves a real name and an age string that `int()` can convert.","hint_1":"Check each option after removing leading and trailing spaces from both values.","hint_2":"Reject rows with an empty cleaned name or an age like a word instead of digits."},"options":{"a":"[' Ava ', ' 12 ']","b":"[' ', '9']","c":"['Leo', 'ten']","d":"['Mia', '4.5']"}},"sc-except-flow":{"title":"What does except catch here?","prompt":"In a `try`/`except ValueError` block, what kind of problem is the `except` meant to handle during `int(age_text)`?","hint":"Think about what happens when text cannot be turned into an integer.","help":{"concept":"`ValueError` is raised when a conversion function like `int()` receives a value of the right general type but with unusable content.","hint_1":"`int()` works for strings like `'7'`, but not for strings that contain words or decimal text in this beginner context.","hint_2":"The problem is not a missing variable name or a syntax mistake in the code editor; it is bad input content during conversion."},"options":{"a":"A text value such as 'ten' that cannot be converted to an integer","b":"A missing `print()` statement","c":"A list index being too large","d":"A file path always being relative"}},"mc-clean-steps":{"title":"Useful cleaning steps","prompt":"Choose all steps that help clean a text row before validation.","hint":"Think about operations that remove formatting noise or standardize text values.","help":{"concept":"Cleaning prepares raw text for validation by removing extra spaces or making formatting more consistent before rule checks happen.","hint_1":"Methods like `strip()` and case normalization help; actions that only display data do not clean it.","hint_2":"Pick the options that change messy input into a more consistent form before checking whether it is valid."},"options":{"a":"Use `strip()` to remove extra spaces around a value","b":"Convert a name like 'aVA' to a consistent case such as title case","c":"Print the row without changing it","d":"Keep all spaces exactly as they were so validation sees the mess"}},"mc-reject-row":{"title":"Which rows should be rejected?","prompt":"A cleaned row is valid only when the name is not empty and the score is an integer from 0 to 100. Choose all rows that should be rejected.","hint":"Check each row after trimming spaces, then test both rules.","help":{"concept":"Validation can involve more than one rule: presence, type conversion, and allowed numeric range.","hint_1":"A row fails if the cleaned name is empty, if the score cannot become an integer, or if the integer is outside 0 to 100.","hint_2":"Look closely at the rows with only spaces for the name, word-based scores, and numbers above the allowed maximum."},"options":{"a":"['Ava', '90']","b":"[' ', '75']","c":"['Leo', 'ten']","d":"['Mia', '105']"}},"dr-clean-order":{"title":"Order the cleaning process","prompt":"Put these steps in a sensible order for cleaning and validating one text value that should become an integer.","hint":"Clean formatting before conversion, and only use the number after conversion succeeds.","help":{"concept":"A reliable cleaning flow removes extra spaces first, then attempts conversion, then uses the converted value for later checks.","hint_1":"If you try `int()` before removing spaces and checking the raw text, your code is harder to reason about.","hint_2":"Start with the original text, clean it, convert it, then continue with numeric validation."},"tokens":{"t1":"Read the text value","t2":"Remove extra spaces with `strip()`","t3":"Convert the cleaned text with `int()`","t4":"Use the integer in later checks"}},"dr-try-except-order":{"title":"Order the try/except flow","prompt":"Arrange these parts to show the usual flow when converting cleaned text to an integer safely.","hint":"The risky conversion belongs inside `try`, and the error handling comes after it.","help":{"concept":"`try` contains code that may fail, while `except` handles a specific error if that failure happens.","hint_1":"Place the conversion attempt after entering `try`, and place the fallback action inside `except ValueError`.","hint_2":"The successful path uses the converted number before the error-handling path appears."},"tokens":{"t1":"Start `try:`","t2":"Attempt `age = int(age_text)`","t3":"Use `age` if conversion worked","t4":"Handle bad input in `except ValueError:`"}},"fb-strip-name":{"title":"Fill the cleaning method","prompt":"Complete the code so it removes extra spaces around the name.","hint":"Use the string method that trims spaces from both ends.","help":{"concept":"Choose the string method that removes whitespace from both ends without changing internal spaces.","hint_1":"The missing value is a method name used like `name.[blank1]()` in Python.","hint_2":"It is the method that turns `' Ava '` into `'Ava'` without changing letters in the middle."},"template":"clean_name = name.[blank1]()","choices":["split","strip","append","write"]},"fb-empty-check":{"title":"Fill the missing comparison","prompt":"Complete the condition so it detects a missing cleaned value.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"if cleaned_name == [blank1]:","choices":["0","None","\"\"","False"]},"ci-clean-name":{"title":"Write a name cleaning function","prompt":"Write `clean_name(text)` so it returns a cleaned version of the name text.","hint":"Read the task \"Write a name cleaning function\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def clean_name(text):\n # return the cleaned name\n pass","solutionCode":"def clean_name(text):\n cleaned = text.strip()\n return cleaned.title()"},"ci-parse-age":{"title":"Parse an age safely","prompt":"Write `parse_age(text)` so it returns an `int` for valid age text and `None` when the text cannot be used as an age.","hint":"Read the task \"Parse an age safely\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def parse_age(text):\n # return an int or None\n pass","solutionCode":"def parse_age(text):\n cleaned = text.strip()\n try:\n return int(cleaned)\n except ValueError:\n return None"},"ci-clean-row":{"title":"Validate and clean one row","prompt":"Write `clean_row(row)` for rows shaped like `[name_text, score_text]`. Return a cleaned dictionary when both values are valid, or `None` when the row should be rejected.","hint":"Read the task \"Validate and clean one row\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def clean_row(row):\n # row looks like [name_text, score_text]\n # return a cleaned dictionary or None\n pass","solutionCode":"def clean_row(row):\n name = row[0].strip()\n score_text = row[1].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n return {\"name\": name.title(), \"score\": score}"},"try-validating-and-cleaning-input-checkpoint":{"title":"Clean and validate a name","prompt":"Read a name. Strip spaces and title-case it. If the cleaned name is empty, print `Missing`; otherwise print the cleaned name.","hint":"Use `.strip()` before checking whether the value is empty.","help":{"concept":"Cleaning input before validation helps programs handle messy text.","hint_1":"Use `.strip()` before checking whether the value is empty.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"name = input()\n\n# Clean and validate the name.\n","solutionCode":"name = input().strip().title()\nif name:\n print(name)\nelse:\n print(\"Missing\")\n","sourceChecks":{"0":{"message":"Strip whitespace from the name."},"1":{"message":"Title-case the cleaned name."}}},"try-validating-and-cleaning-input-sketch0":{"title":"Clean and validate a required name","prompt":"Read a name. Store a cleaned version of `raw_name` with surrounding whitespace removed and title case applied in `cleaned_name`. If an explicit comparison between `cleaned_name` and the empty string, print `Missing`; otherwise print the cleaned name.","hint":"Clean the text before checking whether anything meaningful remains.","help":{"concept":"A spaces-only required field becomes `\"\"` after `strip()`, so validation should check the cleaned value rather than the raw input.","hint_1":"Assign the cleaned result to `cleaned_name`.","hint_2":"Use the explicit comparison `cleaned_name == \"\"` for the missing-value branch."},"starterCode":"raw_name = input()\n\n# Clean raw_name with strip() and title().\n# Print Missing if the cleaned name is \"\"; otherwise print the cleaned name.\n","solutionCode":"raw_name = input()\ncleaned_name = raw_name.strip().title()\n\nif cleaned_name == \"\":\n print(\"Missing\")\nelse:\n print(cleaned_name)\n","sourceChecks":{"0":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"starterFiles":{"main_py":{"content":"raw_name = input()\n\n# Clean raw_name with strip() and title().\n# Print Missing if the cleaned name is \"\"; otherwise print the cleaned name.\n"}},"solutionFiles":{"main_py":{"content":"raw_name = input()\ncleaned_name = raw_name.strip().title()\n\nif cleaned_name == \"\":\n print(\"Missing\")\nelse:\n print(cleaned_name)\n"}}},"try-validating-and-cleaning-input-sketch1":{"title":"Validate integer text and range","prompt":"Read a score, remove surrounding whitespace, and safely convert it with `int()`. Print `Valid score` only when the integer is from 0 through 100. Print `Invalid score` when conversion raises `ValueError` or when the integer is outside that range.","hint":"A valid integer conversion and a valid numeric range are two separate checks.","help":{"concept":"Use `try/except ValueError` for bad integer text, then apply the 0-through-100 range rule to successfully converted values.","hint_1":"Keep `score = int(score_text)` inside `try`.","hint_2":"Check the inclusive range with `0 <= score <= 100`."},"starterCode":"score_text = input()\n\n# Strip score_text, convert it safely with int(),\n# and print Valid score only for integers from 0 through 100.\n# Print Invalid score for bad integer text or an out-of-range number.\n","solutionCode":"score_text = input().strip()\n\ntry:\n score = int(score_text)\n if 0 <= score <= 100:\n print(\"Valid score\")\n else:\n print(\"Invalid score\")\nexcept ValueError:\n print(\"Invalid score\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Check that the score is within 0 to 100."}},"starterFiles":{"main_py":{"content":"score_text = input()\n\n# Strip score_text, convert it safely with int(),\n# and print Valid score only for integers from 0 through 100.\n# Print Invalid score for bad integer text or an out-of-range number.\n"}},"solutionFiles":{"main_py":{"content":"score_text = input().strip()\n\ntry:\n score = int(score_text)\n if 0 <= score <= 100:\n print(\"Valid score\")\n else:\n print(\"Invalid score\")\nexcept ValueError:\n print(\"Invalid score\")\n"}}},"try-validating-and-cleaning-input-sketch2":{"title":"Clean and validate a record","prompt":"Complete `clean_record(name_text, score_text)`. Clean the name with whitespace trimming followed by title-case normalization and the score text with `strip()`. Return `None` for an empty cleaned name, invalid integer score text, or a score outside 0 through 100. Otherwise return `{\"name\": name, \"score\": score}`. The caller should print `Rejected` for `None`; otherwise print `Name:score`.","hint":"Apply the rules in order: clean, check the required name, convert safely, check the range, then return the cleaned dictionary.","help":{"concept":"A reusable cleaning function can return `None` for rejected input and structured cleaned data for accepted input.","hint_1":"Use `name == \"\"` for the missing-name rule and `except ValueError:` for bad score text.","hint_2":"Return the dictionary only after every rejection condition has been passed."},"starterCode":"def clean_record(name_text, score_text):\n # Return {\"name\": cleaned_name, \"score\": score} when both fields are valid.\n # Return None for a missing name, invalid integer text, or a score outside 0..100.\n pass\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\n# Print Rejected for None; otherwise print Name:score.\n","solutionCode":"def clean_record(name_text, score_text):\n name = name_text.strip().title()\n cleaned_score = score_text.strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(cleaned_score)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\nif record is None:\n print(\"Rejected\")\nelse:\n print(record[\"name\"] + \":\" + str(record[\"score\"]))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Split each row into name and score."},"2":{"message":"Strip spaces from each part."},"3":{"message":"Title-case each name."}},"starterFiles":{"main_py":{"content":"def clean_record(name_text, score_text):\n # Return {\"name\": cleaned_name, \"score\": score} when both fields are valid.\n # Return None for a missing name, invalid integer text, or a score outside 0..100.\n pass\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\n# Print Rejected for None; otherwise print Name:score.\n"}},"solutionFiles":{"main_py":{"content":"def clean_record(name_text, score_text):\n name = name_text.strip().title()\n cleaned_score = score_text.strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(cleaned_score)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\nif record is None:\n print(\"Rejected\")\nelse:\n print(record[\"name\"] + \":\" + str(record[\"score\"]))\n"}}},"sc-clean-before-check":{"title":"Clean before checking","prompt":"A required name arrives as `\" \"`. What should the program do before deciding whether the name is missing?","hint":"Whitespace can hide that nothing meaningful was entered.","help":{"concept":"Clean text first, then validate the cleaned value. `strip()` turns a spaces-only string into the empty string.","hint_1":"Checking the raw string would treat several spaces as non-empty text.","hint_2":"Choose the step that removes surrounding whitespace before the missing-value check."},"options":{"a":"Call `.strip()` and then check the cleaned value","b":"Convert the name with `int()`","c":"Append another space","d":"Write the value to a file first"}},"sc-empty-string":{"title":"Detect a missing cleaned value","prompt":"After `cleaned_name = raw_name.strip()`, which comparison directly checks whether the cleaned name is missing?","hint":"A spaces-only string becomes an empty string after `strip()`.","help":{"concept":"The empty string is written as `\"\"`. It is not the number `0`, `None`, or `False`.","hint_1":"Think about the exact value returned by `\" \".strip()`.","hint_2":"Choose the comparison against an empty string literal."},"options":{"a":"cleaned_name == \"\"","b":"cleaned_name == 0","c":"cleaned_name == None","d":"cleaned_name == False"}},"sc-invalid-integer":{"title":"Handle invalid numeric text","prompt":"A cleaned score is `\"ten\"`. What should a safe integer-validation step expect from `int(score_text)`?","hint":"This is the same conversion error handled in the previous topic.","help":{"concept":"`int(...)` raises `ValueError` when cleaned text still cannot represent a whole number.","hint_1":"Cleaning whitespace does not make the word `ten` numeric.","hint_2":"Choose the specific conversion exception introduced in Try/Except Basics."},"options":{"a":"It raises `ValueError`","b":"It returns 0","c":"It returns `None` automatically","d":"It changes the text to `\"10\"`"}},"sc-score-range":{"title":"Validate the allowed range","prompt":"A score successfully converts to the integer `105`. If valid scores must be from 0 through 100, how should the program classify it?","hint":"Successful conversion does not guarantee the number satisfies the rule.","help":{"concept":"Validation can have multiple stages: first confirm conversion works, then check the allowed numeric range.","hint_1":"105 is an integer, so conversion is not the problem.","hint_2":"Compare 105 with the maximum allowed score of 100."},"options":{"a":"Invalid because it is outside 0 through 100","b":"Valid because every integer is accepted","c":"Missing because it is greater than zero","d":"A `FileNotFoundError`"}}},"tryIt":{"try_validating_and_cleaning_input_checkpoint":{"title":"Try it yourself","prompt":"Read a name. Strip spaces and title-case it. If the cleaned name is empty, print `Missing`; otherwise print the cleaned name."},"try_validating_and_cleaning_input_sketch0":{"title":"Try it yourself","prompt":"Read a name. Store a cleaned version of `raw_name` with surrounding whitespace removed and title case applied in `cleaned_name`. If an explicit comparison between `cleaned_name` and the empty string, print `Missing`; otherwise print the cleaned name."},"try_validating_and_cleaning_input_sketch1":{"title":"Try it yourself","prompt":"Safely validate integer text and its allowed range."},"try_validating_and_cleaning_input_sketch2":{"title":"Try it yourself","prompt":"Complete `clean_record(name_text, score_text)`. Clean the name with whitespace trimming followed by title-case normalization and the score text with `strip()`. Return `None` for an empty cleaned name, invalid integer score text, or a score outside 0 through 100. Otherwise return `{\"name\": name, \"score\": score}`. The caller should print `Rejected` for `None`; otherwise print `Name:score`."},"allowReveal":true}},"working-with-paths":{"label":"Working With Paths","summary":"Use relative paths for same-folder and nested files, build path strings from pieces, and use `pathlib.Path` to join path components before opening a file.","cards":{"sketch0":{"title":"Relative paths describe where a file is"},"sketch1":{"title":"Build a path from folder and file-name pieces"},"sketch2":{"title":"Use pathlib.Path to build and open a path"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-relative-path-folder":{"title":"Choose the relative path","prompt":"A file named `input.txt` is inside a folder named `data`. Which path correctly refers to that file in this lesson?","hint":"Use the folder name first, then the file name.","help":{"concept":"A relative path names folders in order from the current workspace location to the target file.","hint_1":"The file is not in the same folder as the code; it is inside `data`.","hint_2":"Look for the choice that joins the folder and file with a forward slash."},"options":{"a":"input.txt/data","b":"data/input.txt","c":"/data/input.txt","d":"data-input.txt"}},"sc-same-folder-path":{"title":"Path for a nearby file","prompt":"Your code and a file named `notes.txt` are in the same folder. Which path should you use to open that file?","hint":"If the file is in the same folder, you do not need to name another folder.","help":{"concept":"A file in the same folder can be opened with just its file name as a relative path.","hint_1":"No extra folder name is needed here.","hint_2":"Choose the shortest valid path that names only the file itself."},"options":{"a":"data/notes.txt","b":"notes.txt","c":"./data/notes.txt","d":"folder/notes.txt"}},"mc-relative-path-benefits":{"title":"Why use relative paths here?","prompt":"Choose all true statements about using relative paths in this lesson.","hint":"Think about paths that work inside the provided workspace and folders.","help":{"concept":"Relative paths are useful because they describe file locations within the project structure instead of depending on one specific machine setup.","hint_1":"Look for statements about project folders and portability inside the lesson workspace.","hint_2":"Select the choices that describe starting from the current workspace and avoiding machine-specific locations."},"options":{"a":"They can point to files in folders like `data/input.txt`.","b":"They depend on one specific computer's full location.","c":"They help organize files by folder.","d":"They always require a full machine-specific location."}},"mc-open-path-examples":{"title":"Valid relative path examples","prompt":"Choose all paths that are valid relative path examples for this lesson's workspace style.","hint":"Reject any choice that changes the named values, branch order, or output.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"notes.txt","b":"data/input.txt","c":"folder -> input.txt","d":"name of the output panel"}},"dr-read-file-steps":{"title":"Order the file-reading steps","prompt":"Put these steps in the correct order for reading a file with a relative path and showing its contents.","hint":"Open first, then read, then display.","help":{"concept":"Reading a file follows a sequence: open the file, get its contents, then print the result.","hint_1":"You cannot read from the file before opening it.","hint_2":"After reading the text into a variable, the last step is to show it in the output panel."},"tokens":{"t1":"Open `data/input.txt` in read mode","t2":"Store the contents in a variable","t3":"Print the variable"}},"dr-build-nested-path":{"title":"Build the path in order","prompt":"Arrange the tokens to make the relative path to `report.txt` inside the `data` folder.","hint":"Folder name comes before the slash and file name.","help":{"concept":"A nested relative path is built as folder, slash, then file name.","hint_1":"Start with the folder that contains the file.","hint_2":"The slash separates the folder name from the file name."},"tokens":{"t1":"data","t2":"/","t3":"report.txt"}},"fb-folder-part":{"title":"Complete the folder path","prompt":"Fill in the missing folder name.","hint":"Read the complete relative path and include the folder that appears before the filename.","help":{"concept":"A relative path to a file inside a folder includes the folder name before the slash.","hint_1":"The missing part is the folder that contains `input.txt`.","hint_2":"Use the folder name shown throughout the lesson examples."},"template":"[blank1]/input.txt","choices":["data","input","files","read"]},"fb-same-folder-file":{"title":"Complete the same-folder path","prompt":"Fill in the missing file name for a file in the same folder.","hint":"No folder name is needed here.","help":{"concept":"When a file is in the same folder, the relative path is just the file name.","hint_1":"The blank should be the exact file name, not a folder.","hint_2":"Choose the option that is a plain file name ending with `.txt`."},"template":"[blank1]","choices":["data/notes.txt","notes.txt","/notes.txt","folder/notes.txt"]},"ci-read-nested-file":{"title":"Read from a nested relative path","prompt":"Open `data/input.txt`, read the text from that relative path, and print it.\n\nYour output should be exactly:\n`Hello paths!`.","hint":"Read the task \"Read from a nested relative path\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/input.txt\", \"r\") as file:\n # read the text and print it\n pass","solutionCode":"with open(\"data/input.txt\", \"r\") as file:\n text = file.read()\n\nprint(text)","sourceChecks":{"0":{"message":"Open data/input.txt to read the nested file."}}},"ci-copy-between-paths":{"title":"Copy text to another relative path","prompt":"Copy the text from `data/source.txt` into `data/copy.txt`, then print the copied text so we can confirm both files match.\n\nYour output should be exactly:\n`apple`\n`banana`.","hint":"Read the task \"Copy text to another relative path\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"# Read from data/source.txt\n# Write the same text to data/copy.txt\n# Print the copied text","solutionCode":"with open(\"data/source.txt\", \"r\") as source:\n text = source.read()\n\nwith open(\"data/copy.txt\", \"w\") as target:\n target.write(text)\n\nprint(text)","sourceChecks":{"0":{"message":"Read from data/source.txt."},"1":{"message":"Write to data/copy.txt."},"2":{"message":"Use file.write() to create the copy."}}},"ci-count-lines-in-folder":{"title":"Count lines from a file path","prompt":"Open `data/items.txt`, count how many lines it contains, and print the result.\n\nYour output should be exactly:\n`3`.","hint":"Read the task \"Count lines from a file path\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/items.txt\", \"r\") as file:\n # count the lines and print the result\n pass","solutionCode":"with open(\"data/items.txt\", \"r\") as file:\n lines = file.readlines()\n\nprint(len(lines))","sourceChecks":{"0":{"message":"Open data/items.txt to count its lines."}}},"try-working-with-paths-checkpoint":{"title":"Use a relative path","prompt":"Use `Path` to read `data/names.txt`, then print the text without extra characters.","hint":"Use `Path(\"data\") / \"names.txt\"`.","help":{"concept":"Build the relative path first, then use it to read the file.","hint_1":"Create the path with `Path(\"data\") / \"names.txt\"`.","hint_2":"Read that path and print the file text without extra characters."},"starterCode":"from pathlib import Path\n\n# Build a path to data/names.txt and print its contents.\n","starterFiles":{"data_names_txt":{"content":"Ava\nMia\n"}},"solutionFiles":{"main_py":{"content":"from pathlib import Path\n\npath = Path(\"data\") / \"names.txt\"\nprint(path.read_text(), end=\"\")\n"},"data_names_txt":{"content":"Ava\nMia\n"}},"sourceChecks":{"0":{"message":"Use Path(...) to build the path."},"1":{"message":"Build the path with Path('data') / 'names.txt'."}},"solutionCode":"from pathlib import Path\n\npath = Path(\"data\") / \"names.txt\"\nprint(path.read_text(), end=\"\")\n"},"try-working-with-paths-sketch0":{"title":"Build a relative path from input","prompt":"Read a folder name and a file name from input. Build the relative path from those two variables using `folder + \"/\" + filename`, store it in `path`, and print `path`. Build a path string by concatenating `folder`, a forward slash, and `filename` in that order. Store the result in a variable named `path`, then print that variable.","hint":"Use both variables instead of typing a completed path.","help":{"concept":"A path string can be assembled from folder and file-name pieces that are already stored in variables.","hint_1":"Keep `folder` first and `filename` last.","hint_2":"Put the slash string between the two variables."},"starterCode":"folder = input().strip()\nfilename = input().strip()\n\n# Build the relative path from folder and filename, then print it.\n","solutionCode":"folder = input().strip()\nfilename = input().strip()\npath = folder + \"/\" + filename\nprint(path)\n","sourceChecks":{"0":{"message":"Build `path` from the two input variables with `folder + \"/\" + filename`."},"1":{"message":"Print the `path` variable itself."}},"starterFiles":{"main_py":{"content":"folder = input().strip()\nfilename = input().strip()\n\n# Build the relative path from folder and filename, then print it.\n"}},"solutionFiles":{"main_py":{"content":"folder = input().strip()\nfilename = input().strip()\npath = folder + \"/\" + filename\nprint(path)\n"}}},"try-working-with-paths-sketch1":{"title":"Join path pieces with pathlib.Path","prompt":"Read a folder name and file name from input. Use `Path(folder) / filename` to build the path, store it in `path`, and print `path`.","hint":"Use the imported `Path` class and the `/` operator between path components.","help":{"concept":"`Path(folder) / filename` joins path components while keeping the result as a path object.","hint_1":"Do not build the finished path by manually typing a slash string in this exercise.","hint_2":"Print the `path` object after joining the components."},"starterCode":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\n\n# Build a Path from folder and filename, then print it.\n","solutionCode":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\npath = Path(folder) / filename\nprint(path)\n","sourceChecks":{"0":{"message":"Call `Path(...)` because that function call is explicitly required by the prompt."},"1":{"message":"Print the constructed `path` object itself."}},"starterFiles":{"main_py":{"content":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\n\n# Build a Path from folder and filename, then print it.\n"}},"solutionFiles":{"main_py":{"content":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\npath = Path(folder) / filename\nprint(path)\n"}}},"try-working-with-paths-sketch2":{"title":"Open a file through a Path object","prompt":"Read a file name from input. Build a `Path` built from the `data` directory and `filename` with pathlib's path-join operator, stored in `path`, open that `path` in read mode, read the text, remove surrounding whitespace, and print it. The workspace provides `data/welcome.txt` and `data/reminder.txt`.","hint":"Build the path first, then pass the `path` variable directly to `open`.","help":{"concept":"A `Path` object can represent the nested relative location and can be passed directly to `open(...)`.","hint_1":"Use `Path(\"data\") / filename` so the input selects the supplied file.","hint_2":"Inside the `with open(path, \"r\")` block, read and strip the text before printing it."},"starterCode":"from pathlib import Path\n\nfilename = input().strip()\n\n# Build a Path inside the data folder.\n# Open that path in read mode and print the stripped text.\n","starterFiles":{"data_message_txt":{"content":"Nested hello\n"},"main_py":{"content":"from pathlib import Path\n\nfilename = input().strip()\n\n# Build a Path inside the data folder.\n# Open that path in read mode and print the stripped text.\n"},"data_welcome_txt":{"content":"Welcome to Python paths!\n"},"data_reminder_txt":{"content":"Remember to save your work.\n"}},"solutionFiles":{"main_py":{"content":"from pathlib import Path\n\nfilename = input().strip()\npath = Path(\"data\") / filename\n\nwith open(path, \"r\") as file:\n text = file.read().strip()\n\nprint(text)\n"},"data_message_txt":{"content":"Nested hello\n"},"data_welcome_txt":{"content":"Welcome to Python paths!\n"},"data_reminder_txt":{"content":"Remember to save your work.\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"solutionCode":"from pathlib import Path\n\nfilename = input().strip()\npath = Path(\"data\") / filename\n\nwith open(path, \"r\") as file:\n text = file.read().strip()\n\nprint(text)\n"},"sc-same-vs-nested":{"title":"Same folder or nested folder","prompt":"Your program is in the workspace root. Which relative path points to `notes.txt` inside the `data` folder?","hint":"Put the containing folder before the file name.","help":{"concept":"A nested relative path names the folder first and then the file, separated by `/`.","hint_1":"`notes.txt` by itself would mean the file is beside `main.py`.","hint_2":"Choose the path that enters `data` before naming `notes.txt`."},"options":{"a":"data/notes.txt","b":"notes.txt/data","c":"/notes.txt","d":"data-notes.txt"}},"sc-path-from-pieces":{"title":"Build a path string from variables","prompt":"If `folder = \"records\"` and `filename = \"scores.txt\"`, which expression builds the relative path `records/scores.txt` from those variables?","hint":"Join folder, slash, and file name in that order.","help":{"concept":"A relative path string can be assembled from existing string variables instead of hard-coding the finished path.","hint_1":"The folder belongs before the slash.","hint_2":"Use both variables so the expression still works if either value changes."},"options":{"a":"folder + \"/\" + filename","b":"filename + \"/\" + folder","c":"\"records/scores.txt\"","d":"folder + filename"}},"sc-pathlib-join":{"title":"Join path parts with Path","prompt":"After `from pathlib import Path`, which expression builds a path from `folder` and `filename`?","hint":"`Path(...)` can be combined with another path part using `/`.","help":{"concept":"`Path(folder) / filename` joins path components without manually inserting a slash string.","hint_1":"Wrap the first path component in `Path(...)`.","hint_2":"Use `/` between the `Path` object and the file-name variable."},"options":{"a":"Path(folder) / filename","b":"Path(folder + filename)","c":"folder.read(filename)","d":"Path / folder / filename()"}},"sc-open-path-object":{"title":"Use a Path object with open","prompt":"If `path` is a `Path` object pointing to a text file, which line opens that path for reading?","hint":"`open(...)` can receive the path object directly.","help":{"concept":"A `Path` object can be passed directly to `open`, just like a relative path string.","hint_1":"Do not convert it to a machine-specific absolute path.","hint_2":"Use the existing `path` variable as the first argument to `open`."},"options":{"a":"with open(path, \"r\") as file:","b":"with path(\"r\") as file:","c":"with open(\"path\", \"r\") as file:","d":"with file.open(\"r\") as path:"}}},"tryIt":{"try_working_with_paths_checkpoint":{"title":"Try it yourself","prompt":"Use `Path` to read `data/names.txt`, then print the text without extra characters."},"try_working_with_paths_sketch0":{"title":"Try it yourself","prompt":"Read a folder name and a file name from input. Build the relative path from those two variables using `folder + \"/\" + filename`, store it in `path`, and print `path`. Build a path string by concatenating `folder`, a forward slash, and `filename` in that order. Store the result in a variable named `path`, then print that variable."},"try_working_with_paths_sketch1":{"title":"Try it yourself","prompt":"Use `Path` to join folder and file-name variables."},"try_working_with_paths_sketch2":{"title":"Try it yourself","prompt":"Read a file name from input. Build a `Path` built from the `data` directory and `filename` with pathlib's path-join operator, stored in `path`, open that `path` in read mode, read the text, remove surrounding whitespace, and print it. The workspace provides `data/welcome.txt` and `data/reminder.txt`."},"allowReveal":true}},"writing-text-files":{"label":"Writing Text Files","summary":"Create or replace text with write mode, preserve existing text with append mode, control line breaks with `\\n`, and reopen the file to verify what was saved.","cards":{"sketch0":{"title":"Write mode creates or replaces a file"},"sketch1":{"title":"Append mode keeps the existing text"},"sketch2":{"title":"Write multiple lines and verify the saved file"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-write-vs-append":{"title":"Choose the mode that replaces old text","prompt":"Which file mode should you use when you want to overwrite any existing text in a file with new text?","hint":"Use the question wording and the lesson example to narrow the choices.","help":{"concept":"This question checks a specific idea from the lesson, not general test-taking strategy.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Remove options that do not match the concept or evidence named in the question."},"options":{"a":"\"a\"","b":"\"w\"","c":"\"r\"","d":"\"x\""}},"sc-verify-written-text":{"title":"Best way to confirm saved text","prompt":"After writing text to a file in this lesson, what is the best way to make the result visible in the output panel?","hint":"Think about reopening the path and showing the saved contents.","help":{"concept":"File-writing exercises should produce observable output, so a common pattern is to reopen the file and print what was written.","hint_1":"Writing changes the file, but the output panel only shows text you print.","hint_2":"Choose the option that reads the saved text back and displays it."},"options":{"a":"Change the editor theme","b":"Reopen the file and print its contents","c":"Open the notes panel","d":"Rename the variable"}},"mc-append-true-statements":{"title":"Facts about append mode","prompt":"Choose all true statements about opening a file with append mode (`\"a\"`).","hint":"Append mode keeps old text and adds new text after it.","help":{"concept":"Append mode writes at the end of existing contents instead of clearing the file first.","hint_1":"Look for statements that describe keeping existing text.","hint_2":"Reject any option that says append mode erases the file before writing."},"options":{"a":"It keeps the existing contents.","b":"It adds new text at the end of the file.","c":"It always removes everything already in the file.","d":"It can be used to add another line to a log."}},"mc-good-writing-patterns":{"title":"Useful patterns when writing text files","prompt":"Choose all practices that fit this topic's file-writing workflow.","hint":"Think about writing text, then making the result observable.","help":{"concept":"Beginner file-writing programs often use `with open(...)` for safe access, newline characters for line breaks, and printed verification after writing.","hint_1":"Look for patterns involving `with open`, `\\n`, and printing saved text.","hint_2":"Avoid choices unrelated to writing or checking file contents."},"options":{"a":"Use `with open(...)` so the file is handled cleanly.","b":"Use `\\n` when you want the next text on a new line.","c":"Print the saved contents after writing so the result is visible.","d":"Change the notes panel before writing."}},"dr-write-file-steps":{"title":"Order the write-and-check steps","prompt":"Put these steps in the correct order for a simple program that writes text and then verifies it.","hint":"Write first, then reopen and display the saved text.","help":{"concept":"A common workflow is open in write mode, write text, reopen in read mode, then print the contents.","hint_1":"The file must be opened for writing before `write()` can happen.","hint_2":"Printing comes after reading the saved contents back."},"tokens":{"t1":"Open the path with mode \"w\"","t2":"Write the text","t3":"Open the same path for reading","t4":"Print the file contents"}},"dr-append-log-sequence":{"title":"Order the append workflow","prompt":"Arrange these actions to show how a program can create a starting log entry, append another entry, and then display the full log.","hint":"The first write creates the starting text before append adds more.","help":{"concept":"To demonstrate append mode clearly, first create initial contents, then append new text, then read the whole file back.","hint_1":"You need some starting text before the append step makes sense.","hint_2":"Reading and printing the full log should happen after both writes are finished."},"tokens":{"t1":"Open the log with mode \"w\" and write the first line","t2":"Open the log with mode \"a\" and add another line","t3":"Open the log for reading","t4":"Print the full log text"}},"fb-write-mode-code":{"title":"Fill the write mode","prompt":"Complete the mode so this code opens the file for overwriting text.","hint":"Focus on the missing concept rather than the exact missing term.","help":{"concept":"The blank should be completed with the term that fits the job being described.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Choose the term that best completes the meaning of the statement."},"template":"with open(\"report.txt\", [blank1]) as file:","choices":["\"r\"","\"a\"","\"w\"","\"x\""]},"fb-newline-choice":{"title":"Fill the line break","prompt":"Choose the text that starts a new line after `First line`.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"file.write(\"First line[blank1]Second line\")","choices":["\\t","\\n","\\r"]},"ci-write-greeting-file":{"title":"Write a personalized greeting file","prompt":"Write a greeting into `greeting.txt` using the input name in title case, then open `greeting.txt` and print its contents.\n\nFor example, if the input is `zoe`, your program should print:\n`Hello, Zoe!`.","hint":"Use `input()` for the name, then write the formatted greeting into the file.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"name = input()\n\n# Write Hello, NAME! to greeting.txt.\n# Then open greeting.txt and print its contents.\n","solutionCode":"name = input().strip().title()\n\nwith open(\"greeting.txt\", \"w\") as file:\n file.write(f\"Hello, {name}!\")\n\nwith open(\"greeting.txt\") as file:\n print(file.read())\n","sourceChecks":{"0":{"message":"Write to greeting.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write greeting.txt."}}},"ci-overwrite-shopping-list":{"title":"Overwrite a shopping list from input","prompt":"A shopping list needs to be rewritten from fresh input. Write both items to `shopping.txt`, one per line and in title case, then print the file contents.\n\nFor example, if the inputs are `bread` and `apples`, your program should print:\n`Bread`\n`Apples`.","hint":"Opening a file with `\"w\"` replaces the old contents.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"first_item = input()\nsecond_item = input()\n\n# Write both items to shopping.txt, one per line.\n# Then print the file contents.\n","solutionCode":"first_item = input().strip().title()\nsecond_item = input().strip().title()\n\nwith open(\"shopping.txt\", \"w\") as file:\n file.write(first_item + \"\\n\")\n file.write(second_item + \"\\n\")\n\nwith open(\"shopping.txt\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Write to shopping.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write shopping.txt."}}},"ci-append-log-entry":{"title":"Append a log entry","prompt":"The log already starts with one line. Append the new input entry to `log.txt` on a new line, then print the full file.\n\nFor example, if the input is `Checked sensors`, your program should print:\n`Start shift`\n`Checked sensors`.","hint":"Opening a file with `\"a\"` keeps the old contents and adds new text at the end.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"entry = input()\n\n# Append the entry to log.txt on a new line, then print the full file.\n","solutionCode":"entry = input().strip()\n\nwith open(\"log.txt\", \"a\") as file:\n file.write(\"\\n\" + entry)\n\nwith open(\"log.txt\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Append to log.txt instead of only printing the answer."},"1":{"message":"Open log.txt in append mode."}}},"try-writing-text-files-checkpoint":{"title":"Write and read a text file","prompt":"Write `Hello from a file!` to `note.txt`, then read the file and print the saved text.","hint":"Open the file in write mode first, then reopen it for reading.","help":{"concept":"Write the file first, then reopen it so you can show exactly what was saved.","hint_1":"Open `note.txt` in write mode and save `Hello from a file!`.","hint_2":"Reopen `note.txt` in read mode and print the text you just wrote."},"starterCode":"# Write Hello from a file! to note.txt.\n# Then read note.txt and print it.\n","solutionCode":"with open(\"note.txt\", \"w\") as file:\n file.write(\"Hello from a file!\")\n\nwith open(\"note.txt\") as file:\n print(file.read())\n","sourceChecks":{"0":{"message":"Write to note.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write the file."}}},"try-writing-text-files-sketch0":{"title":"Replace an old status with fresh input","prompt":"`status.txt` already contains old text. Read one status from input, clean it with whitespace trimming followed by title-case normalization, open `status.txt` with mode `\"w\"`, and write the cleaned status followed by a newline. Then reopen `status.txt` in read mode and print exactly what is saved.","hint":"Write mode should replace the supplied old contents, not add after them.","help":{"concept":"Use mode `\"w\"` when the new text should replace whatever the file contained before.","hint_1":"Store `input().strip().title()` in `status`.","hint_2":"Write `status + \"\\n\"`, then reopen the same file with `\"r\"` and print its contents."},"starterCode":"status = input()\n\n# Clean status, replace status.txt with the new line,\n# then reopen the file and print what was saved.\n","solutionCode":"status = input().strip().title()\n\nwith open(\"status.txt\", \"w\") as file:\n file.write(status + \"\\n\")\n\nwith open(\"status.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Write to note.txt instead of only printing Done."},"1":{"message":"Use file.write() to write note.txt."}},"starterFiles":{"main_py":{"content":"status = input()\n\n# Clean status, replace status.txt with the new line,\n# then reopen the file and print what was saved.\n"},"status_txt":{"content":"Old status\n"}},"solutionFiles":{"main_py":{"content":"status = input().strip().title()\n\nwith open(\"status.txt\", \"w\") as file:\n file.write(status + \"\\n\")\n\nwith open(\"status.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"status_txt":{"content":"Old status\n"}}},"try-writing-text-files-sketch1":{"title":"Append a new log entry","prompt":"`log.txt` already contains `Start shift` on its first line. Read one new entry from input, remove surrounding whitespace, append that entry plus a newline with mode `\"a\"`, then reopen the file and print the complete log. Open `log.txt` in append mode inside a `with` block, write the cleaned entry followed by a newline, then reopen the file for reading and use `read()` to print the complete saved contents. After appending the new line, reopen `log.txt` for reading and use `file.read()` to print the complete saved file.","hint":"Append mode should preserve `Start shift` and add the new entry after it.","help":{"concept":"Use mode `\"a\"` when existing text must remain and the new text belongs at the end.","hint_1":"Store `input().strip()` in `entry`.","hint_2":"Write `entry + \"\\n\"` in append mode, then read the whole log back."},"starterCode":"entry = input()\n\n# Clean entry, append it to log.txt on a new line,\n# then reopen the file and print the complete log.\n","solutionCode":"entry = input().strip()\n\nwith open(\"log.txt\", \"a\") as file:\n file.write(entry + \"\\n\")\n\nwith open(\"log.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Open `log.txt` in append mode `\"a\"` so the existing line is preserved."},"1":{"message":"Write the new entry to the file with `write()`."},"2":{"message":"Read the saved file back with `read()` before displaying the complete log."}},"starterFiles":{"main_py":{"content":"entry = input()\n\n# Clean entry, append it to log.txt on a new line,\n# then reopen the file and print the complete log.\n"},"log_txt":{"content":"Start shift\n"}},"solutionFiles":{"main_py":{"content":"entry = input().strip()\n\nwith open(\"log.txt\", \"a\") as file:\n file.write(entry + \"\\n\")\n\nwith open(\"log.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"log_txt":{"content":"Start shift\n"}}},"try-writing-text-files-sketch2":{"title":"Create a two-line report","prompt":"Read a name and a score from input. Clean the name with whitespace trimming followed by title-case normalization and the score with `.strip()`. Create `report.txt` with mode `\"w\"`. Write exactly two lines: `Name: <name>` and `Score: <score>`, each ending with `\\n`. Reopen the file and print exactly what was saved.","hint":"Use two `file.write(...)` calls so each report line ends with `\\n`.","help":{"concept":"Several calls to `file.write()` can build a multi-line text file deliberately.","hint_1":"Write the name line first and the score line second.","hint_2":"After the write block ends, reopen `report.txt` in read mode and print its contents."},"starterCode":"name = input()\nscore = input()\n\n# Clean the inputs, create report.txt with two labeled lines,\n# then reopen the file and print exactly what was saved.\n","solutionCode":"name = input().strip().title()\nscore = input().strip()\n\nwith open(\"report.txt\", \"w\") as file:\n file.write(\"Name: \" + name + \"\\n\")\n file.write(\"Score: \" + score + \"\\n\")\n\nwith open(\"report.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Write to report.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write report.txt."}},"starterFiles":{"main_py":{"content":"name = input()\nscore = input()\n\n# Clean the inputs, create report.txt with two labeled lines,\n# then reopen the file and print exactly what was saved.\n"}},"solutionFiles":{"main_py":{"content":"name = input().strip().title()\nscore = input().strip()\n\nwith open(\"report.txt\", \"w\") as file:\n file.write(\"Name: \" + name + \"\\n\")\n file.write(\"Score: \" + score + \"\\n\")\n\nwith open(\"report.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"}}},"sc-write-mode-effect":{"title":"What write mode does","prompt":"A file already contains `Old text`. What happens when you open that same path with mode `\"w\"` and write `New text`?","hint":"Write mode does not keep the old contents.","help":{"concept":"Opening a text file with mode `\"w\"` creates the file if needed or replaces its existing contents before new text is written.","hint_1":"The old text is not appended after the new text.","hint_2":"Choose the result containing only the newly written text."},"options":{"a":"The file contains only `New text`","b":"The file contains `Old textNew text`","c":"The file stays unchanged","d":"Python automatically switches to read mode"}},"sc-append-mode-effect":{"title":"What append mode does","prompt":"Which statement correctly describes opening an existing text file with mode `\"a\"`?","hint":"Append mode preserves what is already there.","help":{"concept":"Append mode keeps the existing contents and writes new text at the end of the file.","hint_1":"It does not clear the file first.","hint_2":"Choose the option that preserves old text and adds new text after it."},"options":{"a":"It keeps the existing text and writes new text at the end","b":"It always erases the file before writing","c":"It can only read the existing text","d":"It automatically sorts every line"}},"sc-newline-writing":{"title":"Write the next value on a new line","prompt":"Which string contains two lines when written to a text file?","hint":"The newline escape sequence is `\\n`.","help":{"concept":"`\\n` represents a line break inside a Python string.","hint_1":"The line break belongs between the two pieces of text.","hint_2":"Choose the string containing `\\n` between `First` and `Second`."},"options":{"a":"\"First\\nSecond\"","b":"\"First Second\"","c":"\"First\\tSecond\"","d":"\"First/Second\""}},"sc-verify-saved-file":{"title":"Verify what was saved","prompt":"After a program finishes writing a file, which pattern lets you show the actual saved contents in the output panel?","hint":"Reopen the same path for reading and print what `.read()` returns.","help":{"concept":"Writing changes the file, while reopening it in read mode and printing `.read()` makes the saved contents visible.","hint_1":"Use the same path that was written.","hint_2":"Choose the option that reads the file back instead of printing a separate hard-coded message."},"options":{"a":"Reopen the file in read mode and print `file.read()`","b":"Print the file name as a string","c":"Open a different file and ignore the saved one","d":"Change the variable name used for the writer"}}},"tryIt":{"try_writing_text_files_checkpoint":{"title":"Try it yourself","prompt":"Write `Hello from a file!` to `note.txt`, then read the file and print the saved text."},"try_writing_text_files_sketch0":{"title":"Try it yourself","prompt":"`status.txt` already contains old text. Read one status from input, clean it with whitespace trimming followed by title-case normalization, open `status.txt` with mode `\"w\"`, and write the cleaned status followed by a newline. Then reopen `status.txt` in read mode and print exactly what is saved."},"try_writing_text_files_sketch1":{"title":"Try it yourself","prompt":"`log.txt` already contains `Start shift` on its first line. Read one new entry from input, remove surrounding whitespace, append that entry plus a newline with mode `\"a\"`, then reopen the file and print the complete log. Open `log.txt` in append mode inside a `with` block, write the cleaned entry followed by a newline, then reopen the file for reading and use `read()` to print the complete saved contents. After appending the new line, reopen `log.txt` for reading and use `file.read()` to print the complete saved file."},"try_writing_text_files_sketch2":{"title":"Try it yourself","prompt":"Read a name and a score from input. Clean the name with whitespace trimming followed by title-case normalization and the score with `.strip()`. Create `report.txt` with mode `\"w\"`. Write exactly two lines: `Name: <name>` and `Score: <score>`, each ending with `\\n`. Reopen the file and print exactly what was saved."},"allowReveal":true}}},"python-8-real-world-project":{"community-event-registration-cleaner":{"label":"Final Capstone: Community Event Registration Cleaner","summary":"Build one cumulative registration-cleaning tool that reads CSV rows, validates messy data, moves reusable logic into sibling helper modules, summarizes accepted registrations, writes two report files, and verifies the saved artifacts.","cards":{"sketch0":{"title":"A new domain, the same engineering habits"},"project":{"title":"Community Event Registration Cleaner"}},"projectSteps":{"cp_1":{"title":"Clean and validate one registration"},"cp_2":{"title":"Collect only valid registrations"},"cp_3":{"title":"Move cleaning into a helper module"},"cp_4":{"title":"Add summary helper functions"},"cp_5":{"title":"Write the final report files"},"cp_6":{"title":"Verify the saved artifacts"}},"quiz":{"try-community-event-registration-cleaner-sketch0":{"title":"Inspect the registration export","prompt":"Open `data/registrations.csv` in read mode with `csv.DictReader`. Loop through every data row and print `name|event|seats|email` using the named columns exactly as they appear in the file. Do not clean or reject anything yet.","hint":"Inspect the real CSV shape before you design the cleaner.","help":{"concept":"The preview establishes that the capstone uses a header-based CSV file and named columns, not hand-written row splitting.","hint_1":"Create `reader = csv.DictReader(file)` inside the open-file block.","hint_2":"Loop through `reader` and use all four named columns from each row."},"starterCode":"import csv\n\n# Open data/registrations.csv in read mode.\n# Use csv.DictReader and print every row as name|event|seats|email.\n","starterFiles":{"data_registration_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \n"},"main_py":{"content":"import csv\n\n# Open data/registrations.csv in read mode.\n# Use csv.DictReader and print every row as name|event|seats|email.\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n"},"data_registration_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use a `for` loop as the prompt requests."},"2":{"message":"Normalize the attendee name."},"3":{"message":"Normalize the email address."}}},"cp-1-read-registration-file":{"title":"Clean and validate one registration","prompt":"Start from the CSV preview. Add `clean_row(row)`. Clean `name` with whitespace trimming followed by title-case normalization, strip `event`, strip and lowercase `email`, and strip the seat text before conversion. Return `None` when the cleaned name, event, or email is empty, when seats cannot convert with `int()`, or when seats is less than 1. Otherwise return a dictionary with keys `name`, `event`, `seats`, and `email`. Print `clean_row(row)` for every CSV row so you can see which rows are accepted. Inside `clean_row(row)`, clean the required fields with the specified string methods: trim whitespace from each text field, title-case the cleaned name, lowercase the cleaned email, and convert the cleaned seat text to an integer. Catch `ValueError` when the seat conversion fails.","hint":"Apply the cleaning and validation rules inside one reusable function.","help":{"concept":"`clean_row(row)` should return one dependable shape for valid data and `None` for every rejected registration.","hint_1":"Check missing cleaned text before converting the seat count.","hint_2":"Catch exactly `ValueError`, then reject seat counts below 1."},"starterCode":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n","starterFiles":{"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Use the explicitly requested dictionary field `name`."},"2":{"message":"Use the explicitly requested dictionary field `event`."},"3":{"message":"Use the explicitly requested dictionary field `seats`."},"4":{"message":"Use the explicitly requested dictionary field `email`."},"5":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"6":{"message":"Use `title()` because that method is explicitly required by the prompt."},"7":{"message":"Call `int(...)` because that function call is explicitly required by the prompt."}}},"cp-2-clean-one-registration":{"title":"Collect only valid registrations","prompt":"Keep the working `clean_row(row)` function. Replace the row-by-row preview with a list named `records`. For each CSV row, call `clean_row(row)` once, store the result in `record`, and append it only when it is not `None`. Print the final `records` list.","hint":"Let `clean_row` decide validity; this step should only collect accepted results.","help":{"concept":"Separating cleaning from collection keeps the workflow readable and prevents duplicated validation logic.","hint_1":"Create `records = []` before opening the file.","hint_2":"Use `if record is not None:` before `records.append(record)`."},"starterCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n","starterFiles":{"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","sourceChecks":{"0":{"message":"Call `clean_row(...)` because that function call is explicitly required by the prompt."}}},"cp-3-skip-bad-registration-rows":{"title":"Move cleaning into a helper module","prompt":"Keep the same accepted `records` behavior, but move the complete `clean_row(row)` function out of `main.py` into a new sibling file named `cleaning.py`. Import it with a from-import that brings `clean_row` in from the `cleaning` module. Do not create a package or `__init__.py`; Module 6 used direct sibling helper modules.","hint":"Move one responsibility without changing the program's behavior.","help":{"concept":"A sibling helper module lets `main.py` orchestrate the workflow while `cleaning.py` owns row cleaning and validation.","hint_1":"Create `cleaning.py` beside `main.py` and place the complete working function there.","hint_2":"Remove the local function definition from `main.py` and import `clean_row` directly."},"starterCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","starterFiles":{"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","sourceChecks":{"0":{"message":"Use the requested import for `clean_row` from `cleaning`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Preserve the deterministic output contract."}}},"cp-4-move-cleaning-to-module":{"title":"Add summary helper functions","prompt":"Create a new sibling file named `summary.py` with `total_seats(records)` and `event_counts(records)`. `total_seats` should use a normal loop to add each record's seats. `event_counts` should build a dictionary by incrementing each event name. Import both helpers in `main.py`, then print `Total seats: <total>` followed by each `event: count` in the dictionary's first-seen event order. In `summary.py`, compute the summary values with a `for` loop over `records`. In `main.py`, print each event/count pair with a `for` loop over the dictionary produced by the event-count helper.","hint":"Use normal loops and dictionaries so the summary stays within concepts already taught.","help":{"concept":"Summary helpers should accept `records` and return values without reading or writing files themselves.","hint_1":"Build the seat total with an accumulator loop.","hint_2":"For counts, use `if event in counts:` to increment an existing key or create it with 1."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","starterFiles":{"tools_cleaning_py":{"content":"def clean_row(line):\n # Move the working cleaning logic here.\n pass\n"},"tools___init___py":{"content":""},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools___init___py":{"content":""},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","sourceChecks":{"0":{"message":"Use the requested import involving `summary`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"3":{"message":"Use a `for` loop as the prompt requests."},"4":{"message":"Use a `for` loop as the prompt requests."}}},"cp-5-add-summary-functions":{"title":"Write the final report files","prompt":"Create a sibling file named `reports.py` with `write_clean_registrations(records)` and `write_summary(total, counts)`. Write `output/clean_registrations.csv` in `\"w\"` mode with the header `name,event,seats,email` and one accepted record per line. Write `output/summary.txt` in `\"w\"` mode with `Total seats: <total>` followed by each `event: count`. Import and call both helpers from `main.py`, then print the concise console summary. The old output files already exist and must be replaced.","hint":"The output files already exist, so ordinary write mode is enough; no directory-creation API is needed.","help":{"concept":"Keep file writing in `reports.py` while `main.py` coordinates cleaning, summarizing, and reporting.","hint_1":"Use fixed output paths inside the report functions rather than default parameters.","hint_2":"Write event counts by looping directly through the counts dictionary; do not sort them."},"starterCode":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","starterFiles":{"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n pass\n\n\ndef event_counts(records):\n pass\n"},"tools___init___py":{"content":""},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n return sum(record[\"seats\"] for record in records)\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n counts[event] = counts.get(event, 0) + 1\n return counts\n"},"tools___init___py":{"content":""},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"reports_py":{"content":"def write_clean_registrations(records):\n with open(\"output/clean_registrations.csv\", \"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(\n record[\"name\"] + \",\" +\n record[\"event\"] + \",\" +\n str(record[\"seats\"]) + \",\" +\n record[\"email\"] + \"\\n\"\n )\n\n\ndef write_summary(total, counts):\n with open(\"output/summary.txt\", \"w\") as file:\n file.write(\"Total seats: \" + str(total) + \"\\n\")\n for event in counts:\n file.write(event + \": \" + str(counts[event]) + \"\\n\")\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","sourceChecks":{"0":{"message":"Use the requested import involving `reports`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"3":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"4":{"message":"Use the literal expression or path that the prompt explicitly asks for."}}},"cp-6-write-final-reports":{"title":"Verify the saved artifacts","prompt":"Keep the complete cleaner, helper modules, summaries, and report writers. After writing both output files, print `Cleaned <count> registrations`, then reopen `output/clean_registrations.csv` and `output/summary.txt` in read mode and print their exact saved contents. The grader checks the files themselves as well as the console output.","hint":"Verify the durable artifacts rather than trusting only the in-memory values.","help":{"concept":"The final capstone should prove that the CSV and summary files were actually overwritten with the cleaned data.","hint_1":"Reopen each output path after the report functions finish.","hint_2":"Use `print(file.read(), end=\"\")` so the saved contents appear exactly as written."},"starterCode":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","starterFiles":{"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n return sum(record[\"seats\"] for record in records)\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n counts[event] = counts.get(event, 0) + 1\n return counts\n"},"tools_reports_py":{"content":"from pathlib import Path\n\n\ndef write_clean_registrations(records, path=\"output/clean_registrations.csv\"):\n pass\n\n\ndef write_summary(total, counts, path=\"output/summary.txt\"):\n pass\n"},"tools___init___py":{"content":""},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"reports_py":{"content":"def write_clean_registrations(records):\n with open(\"output/clean_registrations.csv\", \"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(\n record[\"name\"] + \",\" +\n record[\"event\"] + \",\" +\n str(record[\"seats\"]) + \",\" +\n record[\"email\"] + \"\\n\"\n )\n\n\ndef write_summary(total, counts):\n with open(\"output/summary.txt\", \"w\") as file:\n file.write(\"Total seats: \" + str(total) + \"\\n\")\n for event in counts:\n file.write(event + \": \" + str(counts[event]) + \"\\n\")\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\n\nwith open(\"output/clean_registrations.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n\nwith open(\"output/summary.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n return sum(record[\"seats\"] for record in records)\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n counts[event] = counts.get(event, 0) + 1\n return counts\n"},"tools_reports_py":{"content":"from pathlib import Path\n\n\ndef write_clean_registrations(records, path=\"output/clean_registrations.csv\"):\n output_path = Path(path)\n output_path.parent.mkdir(parents=True, exist_ok=True)\n with output_path.open(\"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(f\"{record['name']},{record['event']},{record['seats']},{record['email']}\\n\")\n\n\ndef write_summary(total, counts, path=\"output/summary.txt\"):\n output_path = Path(path)\n output_path.parent.mkdir(parents=True, exist_ok=True)\n with output_path.open(\"w\") as file:\n file.write(f\"Total seats: {total}\\n\")\n for event, count in sorted(counts.items()):\n file.write(f\"{event}: {count}\\n\")\n"},"tools___init___py":{"content":""},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"reports_py":{"content":"def write_clean_registrations(records):\n with open(\"output/clean_registrations.csv\", \"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(\n record[\"name\"] + \",\" +\n record[\"event\"] + \",\" +\n str(record[\"seats\"]) + \",\" +\n record[\"email\"] + \"\\n\"\n )\n\n\ndef write_summary(total, counts):\n with open(\"output/summary.txt\", \"w\") as file:\n file.write(\"Total seats: \" + str(total) + \"\\n\")\n for event in counts:\n file.write(event + \": \" + str(counts[event]) + \"\\n\")\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\n\nwith open(\"output/clean_registrations.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n\nwith open(\"output/summary.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"2":{"message":"Preserve the deterministic output contract."},"3":{"message":"Create the requested output artifact."}}}},"tryIt":{"try_community_event_registration_cleaner_sketch0":{"title":"Try it yourself","prompt":"Inspect the complete registration export with `csv.DictReader` before the capstone starts."},"allowReveal":true}}}},"python-v2":{"python-v2-0":{"module-0-welcome-board-project":{"label":"Module Project: Build a Welcome Board","summary":"Build one Python welcome board in stages. Preserve working code while adding a useful comment, literals, an arithmetic expression, and a final welcome message.","cards":{"sketch0":{"title":"Build one program, one improvement at a time"},"project":{"title":"Welcome Board Builder"}},"projectSteps":{"mp_1":{"title":"Set the event title"},"mp_2":{"title":"Document the board"},"mp_3":{"title":"Add the event time"},"mp_4":{"title":"Add a numeric literal"},"mp_5":{"title":"Calculate the helper count"},"mp_6":{"title":"Finish the welcome board"}},"quiz":{"mp-1-set-event-title":{"title":"Set the event title","prompt":"Start the welcome board with one line that prints exactly:\n\n`Code Club Open House`","hint":"Use one `print()` call with the title as a string literal.","help":{"concept":"The project begins with one working line. Later stages will keep this line and extend the same program.","hint_1":"The event title is text, so write it as a quoted string.","hint_2":"This stage needs one output line only."},"starterCode":"# Start the board with the event title.\n","solutionCode":"print(\"Code Club Open House\")","sourceChecks":{"0":{"message":"Start with one print call for the exact event title."}}},"mp-2-add-useful-comment":{"title":"Document the board","prompt":"Keep the working title line. Add one useful Python comment on the line above it describing the purpose of the program.\n\nThe program output must still be exactly:\n\n`Code Club Open House`","hint":"A Python comment starts with `#` and should not become output.","help":{"concept":"Comments document code for readers without changing the program's normal output.","hint_1":"Put the comment above the existing `print()` call.","hint_2":"Do not add another printed line in this stage."},"starterCode":"print(\"Code Club Open House\")","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")","sourceChecks":{"0":{"message":"Add one non-empty Python comment immediately above the first `print()` statement."}}},"mp-3-add-event-time":{"title":"Add the event time","prompt":"Keep the comment and title. Add one new output line under the title that prints exactly:\n\n`Doors open at 4 PM`","hint":"Preserve the existing program and add one new `print()` call below the title.","help":{"concept":"A cumulative project grows by preserving correct code and adding one focused improvement.","hint_1":"The comment stays at the top.","hint_2":"The new time line should appear after the event title."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."}}},"mp-4-add-seat-literal":{"title":"Add a numeric literal","prompt":"Keep the board so far. Add these two output lines at the bottom:\n\n`Seats available`\n`24`\n\nPrint `24` as a numeric literal, not as quoted text.","hint":"The label is a string, but the seat count should be the number `24` without quotes.","help":{"concept":"A numeric literal is a number written directly in code. Quoting `24` would turn it into a string instead.","hint_1":"Use one print call for the label and one for the number.","hint_2":"The line for the count should contain `print(24)`, not `print(\"24\")`."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."},"1":{"message":"Print the seat count as the integer literal `24`, not as text."}}},"mp-5-calculate-helper-count":{"title":"Calculate the helper count","prompt":"Keep everything already working. Add these two output lines:\n\n`Helpers ready`\n`6`\n\nDo not type the final `6` directly. Make Python calculate it with the expression `2 * 3`.","hint":"Print the label first, then print the expression `2 * 3` on the next line.","help":{"concept":"An arithmetic expression produces a value. Here the program should calculate the helper count rather than hard-code the result.","hint_1":"Keep `2 * 3` visible in the source code.","hint_2":"The expression should not be inside quotes."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)\nprint(\"Helpers ready\")\nprint(2 * 3)","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."},"1":{"message":"Use the expression `2 * 3` itself to calculate the helper count."}}},"mp-6-add-final-message":{"title":"Finish the welcome board","prompt":"Keep the complete working board from the previous step. Add one final line at the bottom that prints exactly:\n\n`Bring your questions!`\n\nPreserve every earlier line and add only the new final message.","hint":"Start from the working program exactly as it is and add one quoted string in a new `print()` call at the bottom.","help":{"concept":"A cumulative project grows from the previous working solution. The final step should preserve all earlier behavior and add only the new requirement.","hint_1":"Do not rewrite or remove any of the earlier board lines.","hint_2":"The final value is text, so keep it inside matching quotes."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)\nprint(\"Helpers ready\")\nprint(2 * 3)","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)\nprint(\"Helpers ready\")\nprint(2 * 3)\nprint(\"Bring your questions!\")","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."}}}}},"operators-and-expressions":{"label":"Operators and Expressions","summary":"Use Python arithmetic operators, follow operator precedence, and use parentheses to control grouping.","cards":{"sketch0":{"title":"Arithmetic operators change numeric values"},"sketch1":{"title":"Precedence decides which operation happens first"},"sketch2":{"title":"Parentheses let you choose the grouping"},"quiz":{"title":"Quiz"}},"quiz":{"sc-division-operator":{"title":"Choose the division operator","prompt":"Which Python operator divides one numeric value by another?","hint":"Python uses a keyboard symbol for division.","help":{"concept":"Python uses `+` for addition, `-` for subtraction, `*` for multiplication, and `/` for division.","hint_1":"Do not choose the multiplication symbol.","hint_2":"Choose the slash used in an expression such as `8 / 2`."},"options":{"a":"+","b":"-","c":"*","d":"/"}},"sc-precedence-result":{"title":"Apply operator precedence","prompt":"What value does Python produce for `2 + 3 * 4`?","hint":"Multiplication is evaluated before addition.","help":{"concept":"In an expression without grouping parentheses, multiplication and division are evaluated before addition and subtraction.","hint_1":"Evaluate `3 * 4` before combining the result with `2`.","hint_2":"Do not start by evaluating `2 + 3`."},"options":{"a":"14","b":"20","c":"24","d":"9"}},"mc-operator-matches":{"title":"Match operators to their jobs","prompt":"Which operator descriptions are correct? Choose all correct answers.","hint":"Match each symbol with the arithmetic operation it performs.","help":{"concept":"The four basic arithmetic operators are `+` add, `-` subtract, `*` multiply, and `/` divide.","hint_1":"Check the meaning of each symbol independently.","hint_2":"Two distractors deliberately swap operator meanings."},"options":{"a":"`+` adds numeric values","b":"`*` multiplies numeric values","c":"`/` subtracts numeric values","d":"`-` divides numeric values"}},"dr-precedence-steps":{"title":"Trace an ungrouped expression","prompt":"Arrange the evaluation steps for `18 - 8 / 2`.","hint":"Division happens before subtraction.","help":{"concept":"Python evaluates division before subtraction when there are no parentheses changing the grouping.","hint_1":"Start with `8 / 2`.","hint_2":"Use that result in the remaining subtraction."},"tokens":{"t1":"Evaluate `8 / 2`","t2":"Produce `4.0`","t3":"Evaluate `18 - 4.0`","t4":"Produce `14.0`"}},"dr-grouped-steps":{"title":"Trace a grouped expression","prompt":"Arrange the evaluation steps for `(5 + 2) * 3`.","hint":"The grouped addition is evaluated before the multiplication.","help":{"concept":"Parentheses give the grouped expression priority over the surrounding arithmetic.","hint_1":"Start inside the parentheses.","hint_2":"After the group becomes one value, multiply by `3`."},"tokens":{"t1":"Evaluate `5 + 2`","t2":"Produce `7`","t3":"Evaluate `7 * 3`","t4":"Produce `21`"}},"fb-target-operator":{"title":"Choose the operator for a target","prompt":"Choose the operator that makes this expression produce `18`.","hint":"Ask which operation turns 6 and 3 into 18.","help":{"concept":"Choosing an operator means choosing the arithmetic relationship between the two values.","hint_1":"Addition would produce a much smaller result.","hint_2":"Use the operator for multiplication."},"template":"6 [blank1] 3","choices":["+","-","*","/"]},"ci-use-four-operators":{"title":"Use all four arithmetic operators","prompt":"Write four `print()` statements using the values `12` and `3`:\n1. add them\n2. subtract `3` from `12`\n3. multiply them\n4. divide `12` by `3`\n\nUse the arithmetic expressions themselves inside `print(...)`.","hint":"Use one of `+`, `-`, `*`, and `/` on each line.","help":{"concept":"Each arithmetic operator creates a different numeric expression from the same two values.","hint_1":"Keep the four operations in the order requested.","hint_2":"Do not replace the expressions with their final numeric answers."},"starterCode":"# Add 12 and 3\n# Subtract 3 from 12\n# Multiply 12 and 3\n# Divide 12 by 3\n","solutionCode":"print(12 + 3)\nprint(12 - 3)\nprint(12 * 3)\nprint(12 / 3)","sourceChecks":{"0":{"message":"Use four separate `print()` statements, one for each required expression."},"1":{"message":"Use `12 + 3` itself inside the first `print()` call."},"2":{"message":"Use `12 - 3` itself inside the second `print()` call."},"3":{"message":"Use `12 * 3` itself inside the third `print()` call."},"4":{"message":"Use `12 / 3` itself inside the fourth `print()` call."}}},"ci-follow-precedence":{"title":"Let precedence control the result","prompt":"Write two `print()` statements using these expressions exactly:\n- `2 + 3 * 4`\n- `18 - 8 / 2`\n\nDo not add grouping parentheses. Run the program and observe which operations Python evaluates first.","hint":"Place each complete expression inside its own `print()` call.","help":{"concept":"Without grouping parentheses, multiplication and division have higher precedence than addition and subtraction.","hint_1":"Keep the expressions exactly as written.","hint_2":"The purpose is to observe precedence, not to type the final answers."},"starterCode":"# Print the two ungrouped expressions below.\n","solutionCode":"print(2 + 3 * 4)\nprint(18 - 8 / 2)","sourceChecks":{"0":{"message":"Use two separate `print()` statements, one for each required expression."},"1":{"message":"Use `2 + 3 * 4` itself inside the first `print()` call without grouping parentheses."},"2":{"message":"Use `18 - 8 / 2` itself inside the second `print()` call without grouping parentheses."}}},"ci-change-grouping":{"title":"Change the grouping with parentheses","prompt":"The starter code uses `2 + 3 * 4`. Add parentheses so Python adds `2 + 3` first and then multiplies by `4`. Keep the expression inside `print()`.","hint":"Group the addition that should happen first.","help":{"concept":"Parentheses change grouping by forcing the enclosed expression to be evaluated before the surrounding multiplication.","hint_1":"Do not change the numbers or operators.","hint_2":"Place one pair of parentheses around the addition."},"starterCode":"print(2 + 3 * 4)\n","solutionCode":"print((2 + 3) * 4)","sourceChecks":{"0":{"message":"Use the grouped expression `(2 + 3) * 4` itself inside `print()`."}}},"ci-practice-choose-operator":{"title":"Change one operator to reach the target","prompt":"The starter code prints the value of `8 + 4`. Change only the arithmetic operator so the expression becomes `8` times `4`.","hint":"Keep the two numbers and the `print()` call.","help":{"concept":"Changing one operator changes the relationship between the same two numeric values.","hint_1":"Do not replace the expression with `32`.","hint_2":"Use Python's multiplication operator."},"starterCode":"print(8 + 4)\n","solutionCode":"print(8 * 4)","sourceChecks":{"0":{"message":"Keep `8` and `4`, and change only the arithmetic operator to multiplication: `8 * 4`."}}},"ci-practice-compare-grouping":{"title":"Compare grouped and ungrouped expressions","prompt":"Write two lines. First print `10 - 2 * 3`. Then print `(10 - 2) * 3`. Keep both expressions visible in the code so you can compare how grouping changes evaluation.","hint":"The second expression groups the subtraction.","help":{"concept":"The same numbers and operators can produce different values when parentheses change which operation happens first.","hint_1":"The first line has no extra grouping around `10 - 2`.","hint_2":"The second line groups `10 - 2` before multiplying."},"starterCode":"# Print the ungrouped expression, then the grouped expression.\n","solutionCode":"print(10 - 2 * 3)\nprint((10 - 2) * 3)","sourceChecks":{"0":{"message":"Use two separate `print()` statements so both expressions remain visible for comparison."},"1":{"message":"Use `10 - 2 * 3` itself inside the first `print()` call."},"2":{"message":"Use `(10 - 2) * 3` itself inside the second `print()` call."}}},"ci-practice-division-precedence":{"title":"Preserve precedence while editing","prompt":"Complete the starter so it prints the value of `20 - 12 / 3`. Keep the expression ungrouped so division happens before subtraction.","hint":"Use the expression itself rather than its final v</article></body></html>

14:["$","$L15",null,{"formats":"$undefined","locale":"en","messages":{"Module0":{"title":"Module 0 Visual Simulator","badges":{"meta":"{mode} • Vectors • Dot • Projection"},"sections":{"overlays":"Overlays","liveMath":"Live Math","practice":"Practice Mode"},"buttons":{"randomize":"Randomize a & b","reset":"Reset","zeroA":"Zero a","zeroB":"Zero b","newQuestion":"New question","check":"Check","reveal":"Reveal"},"status":{"idle":"Click “New question”. Use overlays to reason visually, then answer.","question":"Question: {prompt}. Enter a number (tolerance ±{tolerance}{unit}).","noQuestion":"No active question. Click “New question” first.","invalidNumber":"Please enter a valid number (e.g., 3.5 or -2).","correct":"✅ Correct. {value} is within tolerance.","incorrect":"❌ Not quite. You said {value}. Try again using the overlays.","noReveal":"No question to reveal. Click “New question” first.","answer":"Answer: {value}{unit}","randomized":"Randomized vectors. 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Purple is $\\vec t_{\\perp \\vec r}$.","alphaUndef":"\\\\text{undefined (}\\\\vec r=\\\\vec 0\\\\text{)}","checkOk":"\\\\approx 0\\ \\text{(perpendicular ✅)}","checkBad":"= {val}\\ \\text{(not } \\perp\\text{)}","overlay":{"perpLabel":"t⊥r","alphaUndef":"α=undef","alpha":"α={val}"}},"vectorBasics":{"title":"**Vector basics**","drag":"Drag the tip of $\\vec v$ (blue).","unit":"- Unit vector:","note":"**Note:** {note}","noteZero":"Zero vector: unit vector is undefined.","noteNonZero":"Unit vector keeps the same direction.","overlay":"green dashed = unit vector"}},"SpanBasis":{"title":"Basis • Subspace • Span ({mode})","subtitle":"Drag a and b, or type values. Then sculpt x = αa + βb.","buttons":{"reset":"Reset","randomIndependent":"Random (independent)","makeDependent":"Make dependent","snap":"Snap α/β"},"toggles":{"showSpan":"Show subspace (line/plane)","showCell":"Show cell (2D)","depthMode":"Depth mode (drag Z)"},"vectors":{"title":"Set vectors","a":"a","b":"b","xyz":"x, y, z"},"mix":{"title":"Mix coefficients","play":"Play","pause":"Pause","speed":"speed","alpha":"α","beta":"β"},"target":{"title":"Target mode","subtitle":"Try to make x match t (watch the error).","on":"On","newTarget":"New target","setTargetEqualsX":"Set target = current x","error":"error ‖x − t‖ ="},"live":{"title":"Live data","a":"a","b":"b","x":"x = αa + βb","independent":"Independent?","independentYes":"Yes (independent)","dependentNo":"No (dependent)","spanDim":"Span dimension","angle":"Angle(a,b)","det":"det(a,b)","area":"area={value}","crossMag":"‖a×b‖","normal":"normal n = a×b","tip":"Tip: if a and b become collinear, det (or a×b) → 0, and the span collapses to a line."},"overlay":{"spanCollapses":"span collapses → a line (dimension 1)","cellLattice":"cell (parallelogram) = one “tile” of the lattice","combo":"x = αa + βb (α={alpha}, β={beta})","targetLabel":"target t","badgeDependent":"Span dim = 1 (line). det≈0 → not a basis for R².","badgeIndependent":"Span dim = 2. det={det} → {a,b} is a basis for R².","error":"error‖x−t‖={value}"},"overlay3d":{"plane":"span{a,b} = a plane","combo":"x = αa + βb (α={alpha}, β={beta})","target":"target t (error={value})","badgeDependent":"Span dim = 1 (line) • basis = any nonzero direction vector","badgeIndependent":"Span dim = 2 (plane) • {a,b} is a basis for that plane"}},"subjects":{"python":{"title":"Python for Beginners","description":"Learn Python step by step with beginner-friendly lessons and hands-on practice.","imageAlt":"Python subject cover"},"c-data-structures":{"title":"Data Structures in C","description":"A trace-first C algorithms course built from CS260 Written Assignment 2: every concept is explained with concrete values, data or call-tree animation, correctness reasoning, runtime analysis, and hands-on implementation.","moreComingSoon":"Later modules can add linked structures, graph traversal, sorting, and deeper asymptotic analysis."},"c-runtime-analysis-asymptotics":{"title":"Runtime Analysis and Asymptotics in C","description":"A private, animation-supported C course that turns loop traces and recursive call chains into exact execution counts, limit comparisons, growth ordering, and formal O, Ω, and Θ proofs.","moreComingSoon":"This course is complete: frequency counting, limit comparisons, inequality proofs, and the cumulative C capstone are all included."},"git-foundations":{"title":"Git Foundations","description":"Learn essential local Git through three small, cumulative, plain-text projects. No programming or web-development knowledge is required.","moreComingSoon":"Branches, merges, remotes, and GitHub collaboration belong to later Git courses."},"linux-terminal-fundamentals":{"title":"Linux Terminal Fundamentals","description":"Learn the Linux terminal from the ground up through safe inspection, navigation, file organization, and cumulative terminal-workspace projects."},"applied-python-projects":{"title":"Applied Python Projects: Object-Oriented Apps","description":"A cumulative, project-first Python course where learners build object-oriented apps across multiple files and finish with a complete OOP capstone.","moreComingSoon":"More Applied Python Projects: Object-Oriented Apps lessons are coming soon."},"python-data-functions":{"title":"Python Data and Functions","description":"Build practical Python skills with lists, tuples, dictionaries, functions, helper modules, files, exceptions, and simple data cleaning.","moreComingSoon":"More Python Data and Functions lessons are coming soon."},"python-v2":{"title":"Python for Beginners","description":"Begin with the first line of Python and grow one complete idea at a time. You will learn how programs display information, remember values, respond to input, make decisions, and repeat work. Each module ends with a connected build, and the final capstone combines the foundations into a clear, testable report program.","moreComingSoon":""},"multi-table-sql":{"title":"Multi-Table SQL & Joins","description":"A focused SQLite course with three standard modules and one final capstone. Learners move directly from single-table reporting into INNER JOIN, multi-table relationship paths, LEFT JOIN, anti-joins, and join-aware counting without repeating earlier SELECT, filtering, alias, aggregate, or GROUP BY lessons.","prerequisites":["SQL Analysis & Reporting, or equivalent experience building clear single-table detail reports and grouped summaries."],"moreComingSoon":"More Multi-Table SQL & Joins lessons are coming soon."},"sql-analysis-reporting":{"title":"SQL Analysis & Reporting","description":"A cumulative SQLite reporting course covering readable output, null-safe calculations, aggregate functions, grouped summaries, conditional reporting, five module projects, and one final executive-report capstone.","prerequisites":["SQL Foundations, or equivalent experience selecting, filtering, sorting, and limiting rows from one table."],"moreComingSoon":"More SQL Analysis & Reporting lessons are coming soon."},"sql-data-management":{"title":"SQL Data Management","description":"Move from reading data to managing it. Add approved rows, correct and remove records with precise conditions, design tables with useful constraints, connect related data, and complete a production-style SQLite capstone.","prerequisites":["Multi-Table SQL & Joins, or equivalent experience reading relational schemas and following primary-key and foreign-key relationships."]},"sql-v2":{"title":"SQL Foundations","description":"Learn to read tables, write SELECT queries, filter rows, sort results, and handle real-world beginner data.","moreComingSoon":"More SQL Foundations lessons are coming soon."},"sql":{"title":"SQL for beginners","description":"Learn SQL from the ground up with beginner-friendly lessons on databases, SELECT, WHERE, sorting, and practical querying","moreComingSoon":"More SQL lessons are coming soon."},"haitian-creole-everyday-grammar":{"title":"Haitian Creole 2: Everyday Grammar & Sentence Building","description":"An A1 continuation of Haitian Creole Foundations that adds article selection, contracted pronouns, deeper possession, expanded questions, health language, past and future time, and natural descriptions without reteaching Course 1.","moreComingSoon":"More Haitian Creole 2: Everyday Grammar & Sentence Building lessons are coming soon."},"haitian-creole-foundations":{"title":"Haitian Creole Foundations","description":"An A0-to-A1 Haitian Creole course that develops listening, speaking, reading, sentence building, and writing together from the first module.","moreComingSoon":"More Haitian Creole Foundations lessons are coming soon."}},"subjectsUi":{"headerTitle":"Choose a course","headerSubtitle":"Start learning in minutes. Pick a course to open its modules.","searchPlaceholder":"Search courses…","searchClear":"Clear","resultsCount":"{count, plural, =0 {No courses} one {# course} other {# courses}}","noSubjectsFound":"No courses found.","enrolled":"Enrolled","enrolling":"Enrolling…","continue":"Continue","openModules":"Open modules","noModulesYet":"No modules yet","comingSoon":"Coming soon"},"topics":{"c-data-structures":{"c-data-structures-module-1-algorithm-design-lab":{"build-and-rebalance-bsts":{"label":"Question 3 — Build and Rebalance Almost-Balanced BSTs","summary":"Trace insertion order, recursive midpoint calls, inorder extraction, and Θ(n) rebuilding","cards":{"question-3-problem":{"title":"Question 3: Preserve Order While Rebuilding Shape"},"bst-animation":{"title":"Step Through Every Insertion and Recursive Call Tree"},"bst-project":{"title":"Hands-on: Build and Rebalance BSTs"}},"projectSteps":{"almost_balanced_bst":{"title":"Hands-on: Build and Rebalance BSTs"}},"finalLab":{"steps":{"almost_balanced_bst":{"title":"Hands-on: Build and Rebalance BSTs","prompt":"Open `structures/bst.c` and implement `bst_build_balanced` and `bst_rebalance`.\n\nWork in two stages:\n\n**Build from a sorted array**\n1. Handle the empty range.\n2. Choose either valid middle element when a range has even length.\n3. Create the root for that range.\n4. Recursively build the left and right ranges and set parent links.\n\n**Rebalance an existing BST**\n1. Traverse inorder to obtain sorted keys or sorted node references.\n2. Rebuild with the midpoint rule.\n3. Return a root whose parent is `NULL`.\n\nThe harness checks ordering, almost-balance, height, and parent links on odd, even, skewed, and empty inputs. Equivalent linear-time designs pass: lower-middle or upper-middle selection, key copying or node relinking, and different helper names are all valid.","hint":"Use a half-open range `[begin,end)`. Its length is `end-begin`; after choosing `middle`, recurse on `[begin,middle)` and `[middle+1,end)`.","help":{"concept":"Inorder traversal converts BST shape into sorted order. Midpoint recursion converts sorted order into a shape whose left/right subtree sizes differ by at most one.","hint_1":"For even range lengths, either middle produces valid subtree sizes; stay consistent.","hint_2":"Pass the newly created root as the `parent` argument for both recursive child calls."},"starterCode":"$16","solutionCode":"$17","starterFiles":{"main_c":{"content":"$18"},"structures_bst_c":{"content":"$19"},"structures_bst_h":{"content":"#ifndef BST_H\n#define BST_H\n\n#include \n#include \n\ntypedef struct Node {\n int key;\n struct Node *left;\n struct Node *right;\n struct Node *parent;\n} Node;\n\nNode *bst_insert(Node *root, int key);\nNode *bst_build_balanced(const int *sorted, size_t n);\nNode *bst_rebalance(Node *root);\nbool bst_is_almost_balanced(const Node *root);\nint bst_height(const Node *root);\nvoid bst_print_inorder(const Node *root);\nvoid bst_free(Node *root);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"$1a"},"structures_bst_c":{"content":"$1b"},"structures_bst_h":{"content":"#ifndef BST_H\n#define BST_H\n\n#include \n#include \n\ntypedef struct Node {\n int key;\n struct Node *left;\n struct Node *right;\n struct Node *parent;\n} Node;\n\nNode *bst_insert(Node *root, int key);\nNode *bst_build_balanced(const int *sorted, size_t n);\nNode *bst_rebalance(Node *root);\nbool bst_is_almost_balanced(const Node *root);\nint bst_height(const Node *root);\nvoid bst_print_inorder(const Node *root);\nvoid bst_free(Node *root);\n\n#endif\n"}},"checks":[{"message":"Run the provided behavioral harness and use the failing case to locate the logic error."},{"message":"Equivalent correct implementations are accepted; no exact source phrase is required."}]}}},"quiz":{"same-bst":{"title":"Which two insertion orders generate the same BST?","prompt":"Which two insertion orders generate the same BST?","hint":"Keep the first value as root, then compare the ancestor relationships inside the values below and above that root.","help":{"concept":"Values destined for the left and right subtrees may be interleaved, but each subtree must preserve the relative order that creates the same ancestors.","hint_1":"Both valid sequences begin with `4`.","hint_2":"Within `{1,2,3}`, value `2` must arrive before `1` and `3`; within `{5,6,7}`, value `6` must arrive before `5` and `7`."},"options":{"a":"(4, 2, 6, 1, 3, 5, 7) and (4, 6, 2, 5, 7, 1, 3)","b":"(4, 2, 6, 1, 3, 5, 7) and (2, 1, 3, 4, 5, 6, 7)","c":"(4, 2, 6, 1, 3, 5, 7) and (7, 6, 5, 4, 3, 2, 1)","d":"(4, 2, 6, 1, 3, 5, 7) and (4, 3, 2, 1, 5, 6, 7)"}}}},"detect-equal-pair-sums":{"label":"Question 2 — Detect Equal Disjoint Pair Sums","summary":"Trace every unordered pair, table update, collision, and Θ(n²) bound","cards":{"question-2-problem":{"title":"Question 2: Turn Pair Comparison into Table Lookup"},"pair-sums-animation":{"title":"Trace the Actual Pair-Sum Function"},"pair-sums-project":{"title":"Hands-on: Implement Equal Pair Sums"}},"projectSteps":{"equal_pair_sums":{"title":"Hands-on: Implement Equal Pair Sums"}},"finalLab":{"steps":{"equal_pair_sums":{"title":"Hands-on: Implement Equal Pair Sums","prompt":"Open `algorithms/pair_sums.c` and implement `has_equal_disjoint_pair_sums`.\n\nUse this implementation checklist:\n\n1. Reject inputs that cannot contain two four-index pairs, such as `n < 4`.\n2. Generate each unordered pair exactly once with `i < j`.\n3. Compute the pair sum and look it up in constant expected or worst-case time.\n4. When the sum was seen before, confirm that the saved pair and current pair use four distinct indices.\n5. Release any allocated memory on both the `true` and `false` paths.\n\nThe required runtime is `O(n²)`. A direct-address table is the demonstrated solution because values are bounded by `k`, but a correct hash-table solution or another equivalent quadratic design also passes. The validator checks behavior and does not search for exact source text such as `2 * k`.","hint":"Trace the pair order `(0,1), (0,2), (0,3), (1,2), ...`. A table entry should remember enough about the first pair to compare indices when the same sum appears again.","help":{"concept":"There are `n(n-1)/2` unordered pairs. If each pair performs O(1) lookup/update work, the complete algorithm is Θ(n²).","hint_1":"The largest value is at most `k-1`, so the largest sum is at most `2k-2`; any safely sized table covering that range is valid.","hint_2":"Do not return true for the same pair encountered twice; store or compare indices explicitly."},"starterCode":"#include \n#include \"algorithms/pair_sums.h\"\n\nstatic void print_case(const char *name, const int *values, size_t n, int k) {\n printf(\"%s=%s\\n\", name,\n has_equal_disjoint_pair_sums(values, n, k) ? \"yes\" : \"no\");\n}\n\nint main(void) {\n const int basic_yes[] = {1, 2, 3, 4};\n const int basic_no[] = {1, 2, 4, 8};\n const int later_yes[] = {1, 2, 4, 5};\n const int upper_yes[] = {2, 5, 9, 12, 15};\n const int distinct_no[] = {1, 3, 7, 12};\n\n print_case(\"basic-yes\", basic_yes, 4, 5);\n print_case(\"basic-no\", basic_no, 4, 9);\n print_case(\"later-yes\", later_yes, 4, 6);\n print_case(\"upper-yes\", upper_yes, 5, 16);\n print_case(\"distinct-no\", distinct_no, 4, 13);\n print_case(\"too-short\", basic_yes, 3, 5);\n print_case(\"null\", NULL, 0, 5);\n return 0;\n}\n","solutionCode":"#include \n#include \"algorithms/pair_sums.h\"\n\nstatic void print_case(const char *name, const int *values, size_t n, int k) {\n printf(\"%s=%s\\n\", name,\n has_equal_disjoint_pair_sums(values, n, k) ? \"yes\" : \"no\");\n}\n\nint main(void) {\n const int basic_yes[] = {1, 2, 3, 4};\n const int basic_no[] = {1, 2, 4, 8};\n const int later_yes[] = {1, 2, 4, 5};\n const int upper_yes[] = {2, 5, 9, 12, 15};\n const int distinct_no[] = {1, 3, 7, 12};\n\n print_case(\"basic-yes\", basic_yes, 4, 5);\n print_case(\"basic-no\", basic_no, 4, 9);\n print_case(\"later-yes\", later_yes, 4, 6);\n print_case(\"upper-yes\", upper_yes, 5, 16);\n print_case(\"distinct-no\", distinct_no, 4, 13);\n print_case(\"too-short\", basic_yes, 3, 5);\n print_case(\"null\", NULL, 0, 5);\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"algorithms/pair_sums.h\"\n\nstatic void print_case(const char *name, const int *values, size_t n, int k) {\n printf(\"%s=%s\\n\", name,\n has_equal_disjoint_pair_sums(values, n, k) ? \"yes\" : \"no\");\n}\n\nint main(void) {\n const int basic_yes[] = {1, 2, 3, 4};\n const int basic_no[] = {1, 2, 4, 8};\n const int later_yes[] = {1, 2, 4, 5};\n const int upper_yes[] = {2, 5, 9, 12, 15};\n const int distinct_no[] = {1, 3, 7, 12};\n\n print_case(\"basic-yes\", basic_yes, 4, 5);\n print_case(\"basic-no\", basic_no, 4, 9);\n print_case(\"later-yes\", later_yes, 4, 6);\n print_case(\"upper-yes\", upper_yes, 5, 16);\n print_case(\"distinct-no\", distinct_no, 4, 13);\n print_case(\"too-short\", basic_yes, 3, 5);\n print_case(\"null\", NULL, 0, 5);\n return 0;\n}\n"},"algorithms_pair_sums_c":{"content":"#include \"pair_sums.h\"\n\nbool has_equal_disjoint_pair_sums(const int *values, size_t n, int k) {\n (void)values;\n (void)n;\n (void)k;\n /* TODO 1: enumerate every unordered pair exactly once. */\n /* TODO 2: remember enough state to recognize an equal-sum disjoint pair. */\n return false;\n}\n"},"algorithms_pair_sums_h":{"content":"#ifndef PAIR_SUMS_H\n#define PAIR_SUMS_H\n\n#include \n#include \n\nbool has_equal_disjoint_pair_sums(const int *values, size_t n, int k);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"algorithms/pair_sums.h\"\n\nstatic void print_case(const char *name, const int *values, size_t n, int k) {\n printf(\"%s=%s\\n\", name,\n has_equal_disjoint_pair_sums(values, n, k) ? \"yes\" : \"no\");\n}\n\nint main(void) {\n const int basic_yes[] = {1, 2, 3, 4};\n const int basic_no[] = {1, 2, 4, 8};\n const int later_yes[] = {1, 2, 4, 5};\n const int upper_yes[] = {2, 5, 9, 12, 15};\n const int distinct_no[] = {1, 3, 7, 12};\n\n print_case(\"basic-yes\", basic_yes, 4, 5);\n print_case(\"basic-no\", basic_no, 4, 9);\n print_case(\"later-yes\", later_yes, 4, 6);\n print_case(\"upper-yes\", upper_yes, 5, 16);\n print_case(\"distinct-no\", distinct_no, 4, 13);\n print_case(\"too-short\", basic_yes, 3, 5);\n print_case(\"null\", NULL, 0, 5);\n return 0;\n}\n"},"algorithms_pair_sums_c":{"content":"$1c"},"algorithms_pair_sums_h":{"content":"#ifndef PAIR_SUMS_H\n#define PAIR_SUMS_H\n\n#include \n#include \n\nbool has_equal_disjoint_pair_sums(const int *values, size_t n, int k);\n\n#endif\n"}},"checks":[{"message":"Run the provided behavioral harness and use the failing case to locate the logic error."},{"message":"Equivalent correct implementations are accepted; no exact source phrase is required."}]}}},"quiz":{"pair-sum-table":{"title":"Why can the O(n²) pair-sum algorithm use a direct-address table?","prompt":"Why can the O(n²) pair-sum algorithm use a direct-address table?","hint":"Use the promise that every positive input value is smaller than `k`. What range can a sum occupy?","help":{"concept":"A pair sum is an integer in a bounded range below `2k`, so it can directly select a table slot in O(1) time.","hint_1":"The nested loops still contribute Θ(n²) pair visits.","hint_2":"The table changes lookup cost, not the number of pairs."},"options":{"a":"The input is already sorted.","b":"Every pair has a different sum.","c":"Each value is positive and smaller than k, so every sum is in a bounded range below 2k.","d":"C arrays automatically resolve hash collisions."}}}},"insert-linked-binary-heap":{"label":"Question 5 — Insert into a Pointer-Based Complete Heap","summary":"Trace the binary index path, node attachment, each upheap swap, and O(log n) cost","cards":{"question-5-problem":{"title":"Question 5: Use the Array Index Without an Array"},"heap-animation":{"title":"Trace heap_insert at Conceptual Index 8"},"heap-project":{"title":"Hands-on: Insert into the Linked Heap"}},"projectSteps":{"pointer_heap_insert":{"title":"Hands-on: Insert into the Linked Heap"}},"finalLab":{"steps":{"pointer_heap_insert":{"title":"Hands-on: Insert into the Linked Heap","prompt":"Open `structures/heap.c` and implement `heap_insert`.\n\nUse the conceptual one-based array index `n + 1` even though the tree is pointer-based:\n\n1. Handle insertion into an empty heap.\n2. Find the highest set bit of index `n + 1`.\n3. Ignore that leading bit; each remaining intermediate bit chooses left (`0`) or right (`1`) while walking to the parent.\n4. Use the final bit to attach the new node on the correct side and set its parent link.\n5. While the new key is smaller than its parent's key, swap keys and move upward.\n\nThe harness checks an empty insertion and concrete positions `8` and `9`, including level order, heap order, node count, and parent links. Any correct O(log n) path method and upheap implementation passes; exact bit-loop syntax is not graded.","hint":"Write the target index in binary. After removing the leading `1`, all but the last bit walk to the parent; the last bit selects the new left or right child.","help":{"concept":"A complete tree has the same positions as a one-based heap array. Binary index bits encode the unique root-to-position path.","hint_1":"For index `8 = 1000₂`, walk left, left, then attach left.","hint_2":"Swap keys during upheap rather than pointer subtrees; the complete-tree shape and parent links then remain unchanged."},"starterCode":"$1d","solutionCode":"$1e","starterFiles":{"main_c":{"content":"$1f"},"structures_heap_c":{"content":"$20"},"structures_heap_h":{"content":"#ifndef HEAP_H\n#define HEAP_H\n\n#include \n#include \n\ntypedef struct HeapNode {\n int key;\n struct HeapNode *left;\n struct HeapNode *right;\n struct HeapNode *parent;\n} HeapNode;\n\nHeapNode *heap_from_level_order(const int *values, size_t n);\nHeapNode *heap_insert(HeapNode *root, size_t n, int value);\nvoid heap_print_level_order(const HeapNode *root);\nbool heap_parent_links_valid(const HeapNode *root, const HeapNode *parent);\nvoid heap_free(HeapNode *root);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"$21"},"structures_heap_c":{"content":"$22"},"structures_heap_h":{"content":"#ifndef HEAP_H\n#define HEAP_H\n\n#include \n#include \n\ntypedef struct HeapNode {\n int key;\n struct HeapNode *left;\n struct HeapNode *right;\n struct HeapNode *parent;\n} HeapNode;\n\nHeapNode *heap_from_level_order(const int *values, size_t n);\nHeapNode *heap_insert(HeapNode *root, size_t n, int value);\nvoid heap_print_level_order(const HeapNode *root);\nbool heap_parent_links_valid(const HeapNode *root, const HeapNode *parent);\nvoid heap_free(HeapNode *root);\n\n#endif\n"}},"checks":[{"message":"Run the provided behavioral harness and use the failing case to locate the logic error."},{"message":"Equivalent correct implementations are accepted; no exact source phrase is required."}]}}}},"priority-queue-with-stacks":{"label":"Question 4 — Build a Priority Queue from Stacks","summary":"Trace every pop, minimum replacement, duplicate preservation, and restore step","cards":{"question-4-problem":{"title":"Question 4: Remove One Minimum Without Random Access"},"priority-queue-animation":{"title":"Trace pq_extract_min with Real Stack Values"},"priority-queue-project":{"title":"Hands-on: Build the Stack Priority Queue"}},"projectSteps":{"priority_queue_stacks":{"title":"Hands-on: Build the Stack Priority Queue"}},"finalLab":{"steps":{"priority_queue_stacks":{"title":"Hands-on: Build the Stack Priority Queue","prompt":"Open `structures/priority_queue.c` and implement `pq_extract_min` using only the provided stack API.\n\nFollow this state checklist:\n\n1. Return `false` when the data stack is empty.\n2. Pop one value into a local `minimum` candidate.\n3. Pop every remaining value from `data`.\n4. When a smaller value appears, move the old minimum to `scratch` and replace it.\n5. Otherwise move the current value to `scratch`—including values equal to the minimum.\n6. Restore every scratch value to `data`, write one minimum to the output pointer, and return `true`.\n\nThe tests check duplicates, full sorted extraction order, a single value, and an empty queue. Equivalent stack-only implementations pass; exact loop syntax and local variable names are not graded.","hint":"Keep exactly one value outside both stacks as the candidate to remove. Every other popped value must eventually reach `scratch` and then return to `data`.","help":{"concept":"A stack exposes only the top, so finding a minimum requires examining all `n` values. The scratch stack temporarily stores the `n-1` values that remain in the queue.","hint_1":"Use `<`, not `<=`, when replacing the current minimum; an equal minimum must remain in the queue.","hint_2":"Restoring scratch reverses it again, so the remaining data stack is ready for the next extraction."},"starterCode":"#include \n#include \"structures/priority_queue.h\"\n\nstatic void fill(PriorityQueue *queue, const int *values, size_t n) {\n pq_init(queue);\n for (size_t i = 0; i < n; i++) {\n pq_insert(queue, values[i]);\n }\n}\n\nint main(void) {\n PriorityQueue queue;\n const int duplicates[] = {4, 1, 3, 1, 2};\n fill(&queue, duplicates, 5);\n\n printf(\"duplicates=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\nextract-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n\n const int single[] = {7};\n fill(&queue, single, 1);\n printf(\"single=\");\n if (pq_extract_min(&queue, &value)) printf(\"%d\", value);\n printf(\"\\nsingle-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n return 0;\n}\n","solutionCode":"#include \n#include \"structures/priority_queue.h\"\n\nstatic void fill(PriorityQueue *queue, const int *values, size_t n) {\n pq_init(queue);\n for (size_t i = 0; i < n; i++) {\n pq_insert(queue, values[i]);\n }\n}\n\nint main(void) {\n PriorityQueue queue;\n const int duplicates[] = {4, 1, 3, 1, 2};\n fill(&queue, duplicates, 5);\n\n printf(\"duplicates=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\nextract-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n\n const int single[] = {7};\n fill(&queue, single, 1);\n printf(\"single=\");\n if (pq_extract_min(&queue, &value)) printf(\"%d\", value);\n printf(\"\\nsingle-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"structures/priority_queue.h\"\n\nstatic void fill(PriorityQueue *queue, const int *values, size_t n) {\n pq_init(queue);\n for (size_t i = 0; i < n; i++) {\n pq_insert(queue, values[i]);\n }\n}\n\nint main(void) {\n PriorityQueue queue;\n const int duplicates[] = {4, 1, 3, 1, 2};\n fill(&queue, duplicates, 5);\n\n printf(\"duplicates=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\nextract-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n\n const int single[] = {7};\n fill(&queue, single, 1);\n printf(\"single=\");\n if (pq_extract_min(&queue, &value)) printf(\"%d\", value);\n printf(\"\\nsingle-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n return 0;\n}\n"},"structures_priority_queue_c":{"content":"#include \"priority_queue.h\"\n\nvoid pq_init(PriorityQueue *queue) { stack_init(&queue->data); stack_init(&queue->scratch); }\nbool pq_insert(PriorityQueue *queue, int priority) { return stack_push(&queue->data, priority); }\n\nbool pq_extract_min(PriorityQueue *queue, int *priority) {\n (void)queue;\n (void)priority;\n /* TODO 1: keep one popped value as the current minimum. */\n /* TODO 2: move every other value through scratch, preserving duplicates. */\n /* TODO 3: restore scratch and return exactly one minimum. */\n return false;\n}\n"},"structures_priority_queue_h":{"content":"#ifndef PRIORITY_QUEUE_H\n#define PRIORITY_QUEUE_H\n\n#include \n#include \"stack.h\"\n\ntypedef struct { Stack data; Stack scratch; } PriorityQueue;\nvoid pq_init(PriorityQueue *queue);\nbool pq_insert(PriorityQueue *queue, int priority);\nbool pq_extract_min(PriorityQueue *queue, int *priority);\n\n#endif\n"},"structures_stack_c":{"content":"#include \"stack.h\"\n\nvoid stack_init(Stack *stack) { stack->size = 0; }\nbool stack_push(Stack *stack, int value) { if (stack->size == STACK_CAPACITY) return false; stack->values[stack->size++] = value; return true; }\nbool stack_pop(Stack *stack, int *value) { if (stack->size == 0) return false; *value = stack->values[--stack->size]; return true; }\nbool stack_is_empty(const Stack *stack) { return stack->size == 0; }\n"},"structures_stack_h":{"content":"#ifndef STACK_H\n#define STACK_H\n\n#include \n#include \n\n#define STACK_CAPACITY 64\n\ntypedef struct { int values[STACK_CAPACITY]; size_t size; } Stack;\nvoid stack_init(Stack *stack);\nbool stack_push(Stack *stack, int value);\nbool stack_pop(Stack *stack, int *value);\nbool stack_is_empty(const Stack *stack);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"structures/priority_queue.h\"\n\nstatic void fill(PriorityQueue *queue, const int *values, size_t n) {\n pq_init(queue);\n for (size_t i = 0; i < n; i++) {\n pq_insert(queue, values[i]);\n }\n}\n\nint main(void) {\n PriorityQueue queue;\n const int duplicates[] = {4, 1, 3, 1, 2};\n fill(&queue, duplicates, 5);\n\n printf(\"duplicates=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\nextract-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n\n const int single[] = {7};\n fill(&queue, single, 1);\n printf(\"single=\");\n if (pq_extract_min(&queue, &value)) printf(\"%d\", value);\n printf(\"\\nsingle-empty=%s\\n\",\n pq_extract_min(&queue, &value) ? \"true\" : \"false\");\n return 0;\n}\n"},"structures_priority_queue_c":{"content":"#include \"priority_queue.h\"\n\nvoid pq_init(PriorityQueue *queue) { stack_init(&queue->data); stack_init(&queue->scratch); }\nbool pq_insert(PriorityQueue *queue, int priority) { return stack_push(&queue->data, priority); }\n\nbool pq_extract_min(PriorityQueue *queue, int *priority) {\n if (stack_is_empty(&queue->data)) return false;\n\n int minimum;\n stack_pop(&queue->data, &minimum);\n\n int current;\n while (stack_pop(&queue->data, ¤t)) {\n if (current < minimum) {\n stack_push(&queue->scratch, minimum);\n minimum = current;\n } else {\n stack_push(&queue->scratch, current);\n }\n }\n\n while (stack_pop(&queue->scratch, ¤t)) {\n stack_push(&queue->data, current);\n }\n\n *priority = minimum;\n return true;\n}\n"},"structures_priority_queue_h":{"content":"#ifndef PRIORITY_QUEUE_H\n#define PRIORITY_QUEUE_H\n\n#include \n#include \"stack.h\"\n\ntypedef struct { Stack data; Stack scratch; } PriorityQueue;\nvoid pq_init(PriorityQueue *queue);\nbool pq_insert(PriorityQueue *queue, int priority);\nbool pq_extract_min(PriorityQueue *queue, int *priority);\n\n#endif\n"},"structures_stack_c":{"content":"#include \"stack.h\"\n\nvoid stack_init(Stack *stack) { stack->size = 0; }\nbool stack_push(Stack *stack, int value) { if (stack->size == STACK_CAPACITY) return false; stack->values[stack->size++] = value; return true; }\nbool stack_pop(Stack *stack, int *value) { if (stack->size == 0) return false; *value = stack->values[--stack->size]; return true; }\nbool stack_is_empty(const Stack *stack) { return stack->size == 0; }\n"},"structures_stack_h":{"content":"#ifndef STACK_H\n#define STACK_H\n\n#include \n#include \n\n#define STACK_CAPACITY 64\n\ntypedef struct { int values[STACK_CAPACITY]; size_t size; } Stack;\nvoid stack_init(Stack *stack);\nbool stack_push(Stack *stack, int value);\nbool stack_pop(Stack *stack, int *value);\nbool stack_is_empty(const Stack *stack);\n\n#endif\n"}},"checks":[{"message":"Run the provided behavioral harness and use the failing case to locate the logic error."},{"message":"Equivalent correct implementations are accepted; no exact source phrase is required."}]}}},"quiz":{"operation-costs":{"title":"Which runtime combination matches the lesson designs?","prompt":"Which runtime combination matches the lesson designs?","hint":"Insertion is one push. Extraction must inspect every stored value. Heap insertion follows one root-to-leaf path.","help":{"concept":"This stack design deliberately makes insertion O(1) and extraction Θ(n); the pointer heap insertion is O(log n).","hint_1":"Count legal stack operations, not array indexing that the abstraction does not expose.","hint_2":"A complete heap has logarithmic height."},"options":{"a":"stack-PQ insert O(1), extractMin O(n), pointer-heap insert Θ(log n)","b":"stack-PQ insert O(n), extractMin O(1), pointer-heap insert Θ(n)","c":"stack-PQ insert O(log n), extractMin O(log n), pointer-heap insert Θ(1)","d":"all three operations are Θ(n²)"}}}},"recursive-boolean-configurations":{"label":"Question 1 — Trace Recursion, Solve the Recurrence","summary":"Build the actual foo(3) call tree, unroll T(n), and prove Θ(2ⁿ)","cards":{"introduction":{"title":"How to Solve Each Written-Assignment Problem"},"question-1-problem":{"title":"Question 1: Read the Function and the Runtime Goal"},"recursion-animation":{"title":"Animate the Complete foo(3) Call Tree"},"recursion-project":{"title":"Hands-on: Implement and Measure foo"}},"projectSteps":{"recursion_runtime":{"title":"Hands-on: Implement and Measure foo"}},"finalLab":{"steps":{"recursion_runtime":{"title":"Hands-on: Implement and Measure foo","prompt":"Open `algorithms/recursion.c`. Implement the two recursive branches, then run the supplied harness. Work in this order:\n\n1. Confirm the base case `i == n`.\n2. Set `bits[i] = true` and recurse with `i + 1`.\n3. Return to the same frame, set `bits[i] = false`, and recurse again.\n4. Check `n = 0`, `1`, `3`, and `4` against the call-tree formulas.\n\nThe validator checks observable counts. Equivalent correct implementations pass; branch order, helper names, formatting, and literal source phrases are not graded.","hint":"For a call with `m = n - i` undecided positions: the base case has one call and one leaf; otherwise the current call contributes one plus the two subtrees for `m - 1`.","help":{"concept":"Every internal call represents one partial Boolean prefix. Its true and false children extend that prefix by one position. Therefore `leaves = 2^n` and `calls = 1 + 2 + ... + 2^n = 2^(n+1) - 1`.","hint_1":"Increment `calls` once, immediately when the helper starts.","hint_2":"After the true recursive call returns, overwrite only `bits[i]` with false; earlier prefix values stay unchanged."},"starterCode":"#include \n#include \"algorithms/recursion.h\"\n\nstatic void print_stats(int n) {\n FooStats stats = foo(n);\n printf(\"n=%d leaves=%ld calls=%ld\\n\", n, stats.leaves, stats.calls);\n}\n\nint main(void) {\n print_stats(0);\n print_stats(1);\n print_stats(3);\n print_stats(4);\n return 0;\n}\n","solutionCode":"#include \n#include \"algorithms/recursion.h\"\n\nstatic void print_stats(int n) {\n FooStats stats = foo(n);\n printf(\"n=%d leaves=%ld calls=%ld\\n\", n, stats.leaves, stats.calls);\n}\n\nint main(void) {\n print_stats(0);\n print_stats(1);\n print_stats(3);\n print_stats(4);\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"algorithms/recursion.h\"\n\nstatic void print_stats(int n) {\n FooStats stats = foo(n);\n printf(\"n=%d leaves=%ld calls=%ld\\n\", n, stats.leaves, stats.calls);\n}\n\nint main(void) {\n print_stats(0);\n print_stats(1);\n print_stats(3);\n print_stats(4);\n return 0;\n}\n"},"algorithms_recursion_c":{"content":"#include \"recursion.h\"\n#include \n\nstatic void foo_rec(bool *bits, int n, int i, FooStats *stats) {\n stats->calls++;\n\n if (i == n) {\n stats->leaves++;\n return;\n }\n\n /* Step 1: assign true at this position and recurse on i + 1. */\n /* Step 2: after that call returns, assign false and recurse again. */\n}\n\nFooStats foo(int n) {\n FooStats stats = {0, 0};\n bool bits[n > 0 ? n : 1];\n foo_rec(bits, n, 0, &stats);\n return stats;\n}\n"},"algorithms_recursion_h":{"content":"#ifndef RECURSION_H\n#define RECURSION_H\n\ntypedef struct {\n long calls;\n long leaves;\n} FooStats;\n\nFooStats foo(int n);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"algorithms/recursion.h\"\n\nstatic void print_stats(int n) {\n FooStats stats = foo(n);\n printf(\"n=%d leaves=%ld calls=%ld\\n\", n, stats.leaves, stats.calls);\n}\n\nint main(void) {\n print_stats(0);\n print_stats(1);\n print_stats(3);\n print_stats(4);\n return 0;\n}\n"},"algorithms_recursion_c":{"content":"#include \"recursion.h\"\n#include \n\nstatic void foo_rec(bool *bits, int n, int i, FooStats *stats) {\n stats->calls++;\n\n if (i == n) {\n stats->leaves++;\n return;\n }\n\n bits[i] = true;\n foo_rec(bits, n, i + 1, stats);\n\n bits[i] = false;\n foo_rec(bits, n, i + 1, stats);\n}\n\nFooStats foo(int n) {\n FooStats stats = {0, 0};\n if (n < 0) return stats;\n bool bits[n > 0 ? n : 1];\n foo_rec(bits, n, 0, &stats);\n return stats;\n}\n"},"algorithms_recursion_h":{"content":"#ifndef RECURSION_H\n#define RECURSION_H\n\ntypedef struct {\n long calls;\n long leaves;\n} FooStats;\n\nFooStats foo(int n);\n\n#endif\n"}},"checks":[{"message":"Run the provided behavioral harness and use the failing case to locate the logic error."},{"message":"Equivalent correct implementations are accepted; no exact source phrase is required."}]}}},"quiz":{"recurrence":{"title":"Which recurrence matches fooRec when printing a completed list is O(1)?","prompt":"Which recurrence matches fooRec when printing a completed list is O(1)?","hint":"One non-base call does constant local work and creates two calls with one fewer undecided position.","help":{"concept":"Define `T(m)` using the number of positions still undecided. Then both children have size `m - 1`.","hint_1":"Count recursive calls, not assignments: there are two recursive calls.","hint_2":"The assignments, comparison, counter update, and return are constant local work."},"options":{"a":"T(n) = T(n - 1) + Θ(1)","b":"T(n) = 2T(n - 1) + Θ(1)","c":"T(n) = T(n / 2) + Θ(n)","d":"T(n) = 2T(n / 2) + Θ(n)"}},"tight-bound":{"title":"What tight bound follows after unrolling the recurrence?","prompt":"What tight bound follows after unrolling the recurrence?","hint":"Unroll until the argument reaches zero; the constants form `1 + 2 + 4 + ...`.","help":{"concept":"After `k` substitutions, `T(n) = 2^k T(n-k) + c(2^k - 1)`. Set `k = n` to reach `T(0)`.","hint_1":"Do not replace the geometric sum by `n`; its terms double.","hint_2":"Both the base-case term and accumulated local work are proportional to `2^n`."},"options":{"a":"Θ(log n)","b":"Θ(n)","c":"Θ(n²)","d":"Θ(2^n)"}}}},"written-assignment-2-lab":{"label":"CS260-Style Algorithm Design Lab","summary":"Use animations and executable C projects to solve five recurrence and data-structure design problems.","cards":{"introduction":{"title":"How This Lesson Uses the Original Assignment"},"question-1-problem":{"title":"Question 1: Read the Recurrence Problem First"},"recursion-animation":{"title":"Question 1 Walkthrough: Recurrence to Tight Bound"},"recursion-project":{"title":"Question 1 C Lab: Build and Measure the Recursion"},"question-2-problem":{"title":"Question 2: Read the Equal Pair-Sum Problem First"},"pair-sums-animation":{"title":"Question 2 Walkthrough: Pair Sums and Buckets"},"pair-sums-project":{"title":"Question 2 C Lab: Detect Equal Disjoint Pair Sums"},"question-3-problem":{"title":"Question 3: Read the BST Problem First"},"bst-animation":{"title":"Question 3 Walkthrough: Build and Rebalance the BST"},"bst-project":{"title":"Question 3 C Lab: Build and Rebalance a BST"},"question-4-problem":{"title":"Question 4: Read the Stack-Only Priority Queue Problem"},"priority-queue-animation":{"title":"Question 4 Walkthrough: Extract One Minimum"},"priority-queue-project":{"title":"Question 4 C Lab: Priority Queue with Stacks"},"question-5-problem":{"title":"Question 5: Read the Linked Heap Problem First"},"heap-animation":{"title":"Question 5 Walkthrough: Follow the Binary Pointer Path"},"heap-project":{"title":"Question 5 C Lab: Insert into the Linked Heap"},"analysis-quiz":{"title":"Check the Five Design and Runtime Arguments"}},"projectSteps":{"recursion_runtime":{"title":"Instrument the Recursive Call Tree"},"equal_pair_sums":{"title":"Detect Equal Disjoint Pair Sums"},"almost_balanced_bst":{"title":"Build and Rebalance an Almost-Balanced BST"},"priority_queue_stacks":{"title":"Implement a Priority Queue with Stacks"},"pointer_heap_insert":{"title":"Insert into a Pointer-Based Heap in O(log n)"}},"finalLab":{"steps":{"recursion_runtime":{"title":"Instrument the Recursive Call Tree","prompt":"Open `algorithms/recursion.c`. Complete `foo_rec` so every non-base call explores both Boolean choices and advances to `i + 1`. The supplied `main.c` runs `foo(4)` and reports the number of leaves and total calls. Use the animation to connect the measurements to `T(n) = 2T(n - 1) + Θ(1)`.","hint":"Each non-base call must make two recursive calls after assigning the current slot.","help":{"concept":"The recursion forms a full binary tree. There are `2^n` leaves and `2^(n+1)-1` total calls, so the runtime is `Θ(2^n)` when printing a completed list is treated as constant time.","hint_1":"Run the supplied test harness after each focused change.","hint_2":"Keep the implementation general; do not print the expected output directly."},"starterCode":"#include \n#include \"algorithms/recursion.h\"\n\nint main(void) {\n FooStats stats = foo(4);\n printf(\"leaves=%ld\\n\", stats.leaves);\n printf(\"calls=%ld\\n\", stats.calls);\n printf(\"tight=Theta(2^n)\\n\");\n return 0;\n}\n","solutionCode":"#include \n#include \"algorithms/recursion.h\"\n\nint main(void) {\n FooStats stats = foo(4);\n printf(\"leaves=%ld\\n\", stats.leaves);\n printf(\"calls=%ld\\n\", stats.calls);\n printf(\"tight=Theta(2^n)\\n\");\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"algorithms/recursion.h\"\n\nint main(void) {\n FooStats stats = foo(4);\n printf(\"leaves=%ld\\n\", stats.leaves);\n printf(\"calls=%ld\\n\", stats.calls);\n printf(\"tight=Theta(2^n)\\n\");\n return 0;\n}\n"},"algorithms_recursion_c":{"content":"#include \"recursion.h\"\n#include \n\nstatic void foo_rec(bool *bits, int n, int i, FooStats *stats) {\n stats->calls++;\n\n if (i == n) {\n stats->leaves++;\n return;\n }\n\n /* TODO: explore the branch where bits[i] is true. */\n /* TODO: explore the branch where bits[i] is false. */\n}\n\nFooStats foo(int n) {\n FooStats stats = {0, 0};\n bool bits[n > 0 ? n : 1];\n foo_rec(bits, n, 0, &stats);\n return stats;\n}\n"},"algorithms_recursion_h":{"content":"#ifndef RECURSION_H\n#define RECURSION_H\n\ntypedef struct {\n long calls;\n long leaves;\n} FooStats;\n\nFooStats foo(int n);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"algorithms/recursion.h\"\n\nint main(void) {\n FooStats stats = foo(4);\n printf(\"leaves=%ld\\n\", stats.leaves);\n printf(\"calls=%ld\\n\", stats.calls);\n printf(\"tight=Theta(2^n)\\n\");\n return 0;\n}\n"},"algorithms_recursion_c":{"content":"#include \"recursion.h\"\n#include \n\nstatic void foo_rec(bool *bits, int n, int i, FooStats *stats) {\n stats->calls++;\n\n if (i == n) {\n stats->leaves++;\n return;\n }\n\n bits[i] = true;\n foo_rec(bits, n, i + 1, stats);\n\n bits[i] = false;\n foo_rec(bits, n, i + 1, stats);\n}\n\nFooStats foo(int n) {\n FooStats stats = {0, 0};\n bool bits[n > 0 ? n : 1];\n foo_rec(bits, n, 0, &stats);\n return stats;\n}\n"},"algorithms_recursion_h":{"content":"#ifndef RECURSION_H\n#define RECURSION_H\n\ntypedef struct {\n long calls;\n long leaves;\n} FooStats;\n\nFooStats foo(int n);\n\n#endif\n"}},"checks":[{"message":"Keep the base case at `i == n`."},{"message":"Assign the true branch before its recursive call."},{"message":"Assign the false branch before its recursive call."}]},"equal_pair_sums":{"title":"Detect Equal Disjoint Pair Sums","prompt":"Open `algorithms/pair_sums.c`. Implement `has_equal_disjoint_pair_sums` in `O(n²)` time. Every value is a unique positive integer smaller than `k`, so a direct table of possible sums is allowed. Examine each unordered pair once, remember the first pair that produced each sum, and return `true` when a later pair with four distinct indices reaches the same sum.","hint":"The largest possible sum is smaller than `2 * k`, so the sum itself can index a collision-free table.","help":{"concept":"Nested loops generate `Θ(n²)` pairs. A direct-address table makes each lookup and insertion `O(1)`, producing `Θ(n²)` total time and `O(k)` auxiliary space.","hint_1":"Run the supplied test harness after each focused change.","hint_2":"Keep the implementation general; do not print the expected output directly."},"starterCode":"#include \n#include \"algorithms/pair_sums.h\"\n\nint main(void) {\n const int case1[] = {1, 2, 3, 4};\n const int case2[] = {1, 2, 4, 8};\n\n printf(\"case1=%s\\n\", has_equal_disjoint_pair_sums(case1, 4, 10) ? \"yes\" : \"no\");\n printf(\"case2=%s\\n\", has_equal_disjoint_pair_sums(case2, 4, 10) ? \"yes\" : \"no\");\n return 0;\n}\n","solutionCode":"#include \n#include \"algorithms/pair_sums.h\"\n\nint main(void) {\n const int case1[] = {1, 2, 3, 4};\n const int case2[] = {1, 2, 4, 8};\n\n printf(\"case1=%s\\n\", has_equal_disjoint_pair_sums(case1, 4, 10) ? \"yes\" : \"no\");\n printf(\"case2=%s\\n\", has_equal_disjoint_pair_sums(case2, 4, 10) ? \"yes\" : \"no\");\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"algorithms/pair_sums.h\"\n\nint main(void) {\n const int case1[] = {1, 2, 3, 4};\n const int case2[] = {1, 2, 4, 8};\n\n printf(\"case1=%s\\n\", has_equal_disjoint_pair_sums(case1, 4, 10) ? \"yes\" : \"no\");\n printf(\"case2=%s\\n\", has_equal_disjoint_pair_sums(case2, 4, 10) ? \"yes\" : \"no\");\n return 0;\n}\n"},"algorithms_pair_sums_c":{"content":"#include \"pair_sums.h\"\n\nbool has_equal_disjoint_pair_sums(const int *values, size_t n, int k) {\n (void)values;\n (void)n;\n (void)k;\n /* TODO: examine each unordered pair and remember the first pair for each sum. */\n return false;\n}\n"},"algorithms_pair_sums_h":{"content":"#ifndef PAIR_SUMS_H\n#define PAIR_SUMS_H\n\n#include \n#include \n\nbool has_equal_disjoint_pair_sums(const int *values, size_t n, int k);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"algorithms/pair_sums.h\"\n\nint main(void) {\n const int case1[] = {1, 2, 3, 4};\n const int case2[] = {1, 2, 4, 8};\n\n printf(\"case1=%s\\n\", has_equal_disjoint_pair_sums(case1, 4, 10) ? \"yes\" : \"no\");\n printf(\"case2=%s\\n\", has_equal_disjoint_pair_sums(case2, 4, 10) ? \"yes\" : \"no\");\n return 0;\n}\n"},"algorithms_pair_sums_c":{"content":"$23"},"algorithms_pair_sums_h":{"content":"#ifndef PAIR_SUMS_H\n#define PAIR_SUMS_H\n\n#include \n#include \n\nbool has_equal_disjoint_pair_sums(const int *values, size_t n, int k);\n\n#endif\n"}},"checks":[{"message":"Use an outer loop over the first pair index."},{"message":"Use an inner loop that visits each unordered pair once."},{"message":"Size the direct-address table from the bounded sum range."}]},"almost_balanced_bst":{"title":"Build and Rebalance an Almost-Balanced BST","prompt":"Open `structures/bst.c`. Implement `bst_build_balanced` from a sorted array and `bst_rebalance` for an arbitrary BST. The required approach is linear: inorder traversal writes the keys in sorted order, and midpoint recursion rebuilds a tree whose left and right subtree sizes differ by at most one at every node.","hint":"Use half-open array ranges. Choose one middle key as the root, then recurse on the left and right ranges.","help":{"concept":"Inorder traversal visits each node once, and midpoint construction creates each replacement node once. The two passes are `Θ(n)`, and every recursive range splits into sizes that differ by at most one.","hint_1":"Run the supplied test harness after each focused change.","hint_2":"Keep the implementation general; do not print the expected output directly."},"starterCode":"#include \n#include \"structures/bst.h\"\n\nint main(void) {\n Node *root = NULL;\n for (int value = 1; value <= 7; value++) {\n root = bst_insert(root, value);\n }\n\n root = bst_rebalance(root);\n printf(\"balanced=%s\\n\", bst_is_almost_balanced(root) ? \"yes\" : \"no\");\n printf(\"inorder=\");\n bst_print_inorder(root);\n printf(\"\\nheight=%d\\n\", bst_height(root));\n\n bst_free(root);\n return 0;\n}\n","solutionCode":"#include \n#include \"structures/bst.h\"\n\nint main(void) {\n Node *root = NULL;\n for (int value = 1; value <= 7; value++) {\n root = bst_insert(root, value);\n }\n\n root = bst_rebalance(root);\n printf(\"balanced=%s\\n\", bst_is_almost_balanced(root) ? \"yes\" : \"no\");\n printf(\"inorder=\");\n bst_print_inorder(root);\n printf(\"\\nheight=%d\\n\", bst_height(root));\n\n bst_free(root);\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"structures/bst.h\"\n\nint main(void) {\n Node *root = NULL;\n for (int value = 1; value <= 7; value++) {\n root = bst_insert(root, value);\n }\n\n root = bst_rebalance(root);\n printf(\"balanced=%s\\n\", bst_is_almost_balanced(root) ? \"yes\" : \"no\");\n printf(\"inorder=\");\n bst_print_inorder(root);\n printf(\"\\nheight=%d\\n\", bst_height(root));\n\n bst_free(root);\n return 0;\n}\n"},"structures_bst_c":{"content":"$24"},"structures_bst_h":{"content":"#ifndef BST_H\n#define BST_H\n\n#include \n#include \n\ntypedef struct Node {\n int key;\n struct Node *left;\n struct Node *right;\n struct Node *parent;\n} Node;\n\nNode *bst_insert(Node *root, int key);\nNode *bst_build_balanced(const int *sorted, size_t n);\nNode *bst_rebalance(Node *root);\nbool bst_is_almost_balanced(const Node *root);\nint bst_height(const Node *root);\nvoid bst_print_inorder(const Node *root);\nvoid bst_free(Node *root);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"structures/bst.h\"\n\nint main(void) {\n Node *root = NULL;\n for (int value = 1; value <= 7; value++) {\n root = bst_insert(root, value);\n }\n\n root = bst_rebalance(root);\n printf(\"balanced=%s\\n\", bst_is_almost_balanced(root) ? \"yes\" : \"no\");\n printf(\"inorder=\");\n bst_print_inorder(root);\n printf(\"\\nheight=%d\\n\", bst_height(root));\n\n bst_free(root);\n return 0;\n}\n"},"structures_bst_c":{"content":"$25"},"structures_bst_h":{"content":"#ifndef BST_H\n#define BST_H\n\n#include \n#include \n\ntypedef struct Node {\n int key;\n struct Node *left;\n struct Node *right;\n struct Node *parent;\n} Node;\n\nNode *bst_insert(Node *root, int key);\nNode *bst_build_balanced(const int *sorted, size_t n);\nNode *bst_rebalance(Node *root);\nbool bst_is_almost_balanced(const Node *root);\nint bst_height(const Node *root);\nvoid bst_print_inorder(const Node *root);\nvoid bst_free(Node *root);\n\n#endif\n"}},"checks":[{"message":"Choose a midpoint from each sorted subrange."},{"message":"Collect the original BST keys with an inorder traversal."},{"message":"Rebuild the tree from the sorted key array."}]},"priority_queue_stacks":{"title":"Implement a Priority Queue with Stacks","prompt":"Open `structures/priority_queue.c`. Keep `insert` as one stack push. Implement `extract_min` using only `push`, `pop`, and `isEmpty` behavior: pop every priority, retain exactly one smallest value, move all other values through the scratch stack, and restore them to the data stack. Duplicate minimum priorities must be removed one at a time.","hint":"Initialize the minimum from the first pop. When a smaller value appears, move the old minimum into the scratch stack.","help":{"concept":"This design makes `insert` `O(1)`. `extract_min` performs a scan and a restore pass, both linear in the number of stored priorities, so it is `O(n)` and uses `O(n)` auxiliary stack capacity.","hint_1":"Run the supplied test harness after each focused change.","hint_2":"Keep the implementation general; do not print the expected output directly."},"starterCode":"#include \n#include \"structures/priority_queue.h\"\n\nint main(void) {\n PriorityQueue queue;\n pq_init(&queue);\n const int values[] = {4, 1, 3, 1, 2};\n for (size_t i = 0; i < sizeof(values) / sizeof(values[0]); i++) {\n pq_insert(&queue, values[i]);\n }\n\n printf(\"order=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\ninsert=O(1)\\nextract=O(n)\\n\");\n return 0;\n}\n","solutionCode":"#include \n#include \"structures/priority_queue.h\"\n\nint main(void) {\n PriorityQueue queue;\n pq_init(&queue);\n const int values[] = {4, 1, 3, 1, 2};\n for (size_t i = 0; i < sizeof(values) / sizeof(values[0]); i++) {\n pq_insert(&queue, values[i]);\n }\n\n printf(\"order=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\ninsert=O(1)\\nextract=O(n)\\n\");\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"structures/priority_queue.h\"\n\nint main(void) {\n PriorityQueue queue;\n pq_init(&queue);\n const int values[] = {4, 1, 3, 1, 2};\n for (size_t i = 0; i < sizeof(values) / sizeof(values[0]); i++) {\n pq_insert(&queue, values[i]);\n }\n\n printf(\"order=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\ninsert=O(1)\\nextract=O(n)\\n\");\n return 0;\n}\n"},"structures_priority_queue_c":{"content":"#include \"priority_queue.h\"\n\nvoid pq_init(PriorityQueue *queue) { stack_init(&queue->data); stack_init(&queue->scratch); }\nbool pq_insert(PriorityQueue *queue, int priority) { return stack_push(&queue->data, priority); }\n\nbool pq_extract_min(PriorityQueue *queue, int *priority) {\n (void)queue;\n (void)priority;\n /* TODO: pop through data, keep one minimum aside, then restore all other values. */\n return false;\n}\n"},"structures_priority_queue_h":{"content":"#ifndef PRIORITY_QUEUE_H\n#define PRIORITY_QUEUE_H\n\n#include \n#include \"stack.h\"\n\ntypedef struct { Stack data; Stack scratch; } PriorityQueue;\nvoid pq_init(PriorityQueue *queue);\nbool pq_insert(PriorityQueue *queue, int priority);\nbool pq_extract_min(PriorityQueue *queue, int *priority);\n\n#endif\n"},"structures_stack_c":{"content":"#include \"stack.h\"\n\nvoid stack_init(Stack *stack) { stack->size = 0; }\nbool stack_push(Stack *stack, int value) { if (stack->size == STACK_CAPACITY) return false; stack->values[stack->size++] = value; return true; }\nbool stack_pop(Stack *stack, int *value) { if (stack->size == 0) return false; *value = stack->values[--stack->size]; return true; }\nbool stack_is_empty(const Stack *stack) { return stack->size == 0; }\n"},"structures_stack_h":{"content":"#ifndef STACK_H\n#define STACK_H\n\n#include \n#include \n\n#define STACK_CAPACITY 64\n\ntypedef struct { int values[STACK_CAPACITY]; size_t size; } Stack;\nvoid stack_init(Stack *stack);\nbool stack_push(Stack *stack, int value);\nbool stack_pop(Stack *stack, int *value);\nbool stack_is_empty(const Stack *stack);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"structures/priority_queue.h\"\n\nint main(void) {\n PriorityQueue queue;\n pq_init(&queue);\n const int values[] = {4, 1, 3, 1, 2};\n for (size_t i = 0; i < sizeof(values) / sizeof(values[0]); i++) {\n pq_insert(&queue, values[i]);\n }\n\n printf(\"order=\");\n int value;\n while (pq_extract_min(&queue, &value)) {\n printf(\"%d \", value);\n }\n printf(\"\\ninsert=O(1)\\nextract=O(n)\\n\");\n return 0;\n}\n"},"structures_priority_queue_c":{"content":"#include \"priority_queue.h\"\n\nvoid pq_init(PriorityQueue *queue) { stack_init(&queue->data); stack_init(&queue->scratch); }\nbool pq_insert(PriorityQueue *queue, int priority) { return stack_push(&queue->data, priority); }\n\nbool pq_extract_min(PriorityQueue *queue, int *priority) {\n if (stack_is_empty(&queue->data)) return false;\n\n int minimum;\n stack_pop(&queue->data, &minimum);\n\n int current;\n while (stack_pop(&queue->data, ¤t)) {\n if (current < minimum) {\n stack_push(&queue->scratch, minimum);\n minimum = current;\n } else {\n stack_push(&queue->scratch, current);\n }\n }\n\n while (stack_pop(&queue->scratch, ¤t)) {\n stack_push(&queue->data, current);\n }\n\n *priority = minimum;\n return true;\n}\n"},"structures_priority_queue_h":{"content":"#ifndef PRIORITY_QUEUE_H\n#define PRIORITY_QUEUE_H\n\n#include \n#include \"stack.h\"\n\ntypedef struct { Stack data; Stack scratch; } PriorityQueue;\nvoid pq_init(PriorityQueue *queue);\nbool pq_insert(PriorityQueue *queue, int priority);\nbool pq_extract_min(PriorityQueue *queue, int *priority);\n\n#endif\n"},"structures_stack_c":{"content":"#include \"stack.h\"\n\nvoid stack_init(Stack *stack) { stack->size = 0; }\nbool stack_push(Stack *stack, int value) { if (stack->size == STACK_CAPACITY) return false; stack->values[stack->size++] = value; return true; }\nbool stack_pop(Stack *stack, int *value) { if (stack->size == 0) return false; *value = stack->values[--stack->size]; return true; }\nbool stack_is_empty(const Stack *stack) { return stack->size == 0; }\n"},"structures_stack_h":{"content":"#ifndef STACK_H\n#define STACK_H\n\n#include \n#include \n\n#define STACK_CAPACITY 64\n\ntypedef struct { int values[STACK_CAPACITY]; size_t size; } Stack;\nvoid stack_init(Stack *stack);\nbool stack_push(Stack *stack, int value);\nbool stack_pop(Stack *stack, int *value);\nbool stack_is_empty(const Stack *stack);\n\n#endif\n"}},"checks":[{"message":"Scan the data stack using only pop operations."},{"message":"Use the scratch stack to preserve every nonremoved priority."},{"message":"Return exactly one minimum priority."}]},"pointer_heap_insert":{"title":"Insert into a Pointer-Based Heap in O(log n)","prompt":"Open `structures/heap.c`. Implement `heap_insert` without scanning the tree. The next node occupies conceptual array index `n + 1`. Read that index in binary: after the leading `1`, each remaining bit selects left (`0`) or right (`1`). Traverse all path bits except the final attachment bit, link the new node with its parent, then upheap by swapping keys.","hint":"For index `8`, binary `1000` means root → left → left, then attach as the left child.","help":{"concept":"The complete-tree height is `Θ(log n)`. Decoding the index path takes one pointer step per tree level, and upheap also moves at most one level at a time, so insertion is `Θ(log n)`.","hint_1":"Run the supplied test harness after each focused change.","hint_2":"Keep the implementation general; do not print the expected output directly."},"starterCode":"#include \n#include \"structures/heap.h\"\n\nint main(void) {\n const int initial[] = {10, 20, 15, 30, 40, 50, 60};\n HeapNode *root = heap_from_level_order(initial, 7);\n root = heap_insert(root, 7, 5);\n\n printf(\"level=\");\n heap_print_level_order(root);\n printf(\"\\nparent-links=%s\\n\", heap_parent_links_valid(root, NULL) ? \"yes\" : \"no\");\n\n heap_free(root);\n return 0;\n}\n","solutionCode":"#include \n#include \"structures/heap.h\"\n\nint main(void) {\n const int initial[] = {10, 20, 15, 30, 40, 50, 60};\n HeapNode *root = heap_from_level_order(initial, 7);\n root = heap_insert(root, 7, 5);\n\n printf(\"level=\");\n heap_print_level_order(root);\n printf(\"\\nparent-links=%s\\n\", heap_parent_links_valid(root, NULL) ? \"yes\" : \"no\");\n\n heap_free(root);\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"structures/heap.h\"\n\nint main(void) {\n const int initial[] = {10, 20, 15, 30, 40, 50, 60};\n HeapNode *root = heap_from_level_order(initial, 7);\n root = heap_insert(root, 7, 5);\n\n printf(\"level=\");\n heap_print_level_order(root);\n printf(\"\\nparent-links=%s\\n\", heap_parent_links_valid(root, NULL) ? \"yes\" : \"no\");\n\n heap_free(root);\n return 0;\n}\n"},"structures_heap_c":{"content":"$26"},"structures_heap_h":{"content":"#ifndef HEAP_H\n#define HEAP_H\n\n#include \n#include \n\ntypedef struct HeapNode {\n int key;\n struct HeapNode *left;\n struct HeapNode *right;\n struct HeapNode *parent;\n} HeapNode;\n\nHeapNode *heap_from_level_order(const int *values, size_t n);\nHeapNode *heap_insert(HeapNode *root, size_t n, int value);\nvoid heap_print_level_order(const HeapNode *root);\nbool heap_parent_links_valid(const HeapNode *root, const HeapNode *parent);\nvoid heap_free(HeapNode *root);\n\n#endif\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"structures/heap.h\"\n\nint main(void) {\n const int initial[] = {10, 20, 15, 30, 40, 50, 60};\n HeapNode *root = heap_from_level_order(initial, 7);\n root = heap_insert(root, 7, 5);\n\n printf(\"level=\");\n heap_print_level_order(root);\n printf(\"\\nparent-links=%s\\n\", heap_parent_links_valid(root, NULL) ? \"yes\" : \"no\");\n\n heap_free(root);\n return 0;\n}\n"},"structures_heap_c":{"content":"$27"},"structures_heap_h":{"content":"#ifndef HEAP_H\n#define HEAP_H\n\n#include \n#include \n\ntypedef struct HeapNode {\n int key;\n struct HeapNode *left;\n struct HeapNode *right;\n struct HeapNode *parent;\n} HeapNode;\n\nHeapNode *heap_from_level_order(const int *values, size_t n);\nHeapNode *heap_insert(HeapNode *root, size_t n, int value);\nvoid heap_print_level_order(const HeapNode *root);\nbool heap_parent_links_valid(const HeapNode *root, const HeapNode *parent);\nvoid heap_free(HeapNode *root);\n\n#endif\n"}},"checks":[{"message":"Use the conceptual next array index."},{"message":"Find the leading binary bit before traversing the path."},{"message":"Maintain parent links and use them during upheap."}]}}},"quiz":{"recurrence":{"title":"Which recurrence matches fooRec when printing a completed list is O(1)?","prompt":"Which recurrence matches fooRec when printing a completed list is O(1)?","hint":"Trace the relevant animation and identify the operation that dominates the runtime.","help":{"concept":"Every non-base call performs constant local work and makes two calls with one fewer undecided position.","hint_1":"Separate correctness from runtime: first identify what the algorithm must do.","hint_2":"Then count the loops, recursion branches, stack transfers, or pointer levels involved."},"options":{"a":"T(n) = T(n - 1) + Θ(1)","b":"T(n) = 2T(n - 1) + Θ(1)","c":"T(n) = T(n / 2) + Θ(n)","d":"T(n) = 2T(n / 2) + Θ(n)"}},"tight-bound":{"title":"What tight bound follows after unrolling the recurrence?","prompt":"What tight bound follows after unrolling the recurrence?","hint":"Trace the relevant animation and identify the operation that dominates the runtime.","help":{"concept":"The recursion tree doubles at every level and has 2^n leaves.","hint_1":"Separate correctness from runtime: first identify what the algorithm must do.","hint_2":"Then count the loops, recursion branches, stack transfers, or pointer levels involved."},"options":{"a":"Θ(log n)","b":"Θ(n)","c":"Θ(n²)","d":"Θ(2^n)"}},"same-bst":{"title":"Which two insertion orders generate the same BST?","prompt":"Which two insertion orders generate the same BST?","hint":"Trace the relevant animation and identify the operation that dominates the runtime.","help":{"concept":"The root must remain 4, and the relative insertion order must preserve the same left and right ancestor relationships.","hint_1":"Separate correctness from runtime: first identify what the algorithm must do.","hint_2":"Then count the loops, recursion branches, stack transfers, or pointer levels involved."},"options":{"a":"(4, 2, 6, 1, 3, 5, 7) and (4, 6, 2, 5, 7, 1, 3)","b":"(4, 2, 6, 1, 3, 5, 7) and (2, 1, 3, 4, 5, 6, 7)","c":"(4, 2, 6, 1, 3, 5, 7) and (7, 6, 5, 4, 3, 2, 1)","d":"(4, 2, 6, 1, 3, 5, 7) and (4, 3, 2, 1, 5, 6, 7)"}},"pair-sum-table":{"title":"Why can the O(n²) pair-sum algorithm use a direct-address table?","prompt":"Why can the O(n²) pair-sum algorithm use a direct-address table?","hint":"Trace the relevant animation and identify the operation that dominates the runtime.","help":{"concept":"The bounded value range turns each possible sum into a valid table index, so no hash function is needed.","hint_1":"Separate correctness from runtime: first identify what the algorithm must do.","hint_2":"Then count the loops, recursion branches, stack transfers, or pointer levels involved."},"options":{"a":"The input is already sorted.","b":"Every pair has a different sum.","c":"Each value is positive and smaller than k, so every sum is in a bounded range below 2k.","d":"C arrays automatically resolve hash collisions."}},"operation-costs":{"title":"Which runtime combination matches the lesson designs?","prompt":"Which runtime combination matches the lesson designs?","hint":"Trace the relevant animation and identify the operation that dominates the runtime.","help":{"concept":"The stack design defers work to extraction, while the heap follows one root-to-leaf path and then upheaps along that path.","hint_1":"Separate correctness from runtime: first identify what the algorithm must do.","hint_2":"Then count the loops, recursion branches, stack transfers, or pointer levels involved."},"options":{"a":"stack-PQ insert O(1), extractMin O(n), pointer-heap insert Θ(log n)","b":"stack-PQ insert O(n), extractMin O(1), pointer-heap insert Θ(n)","c":"stack-PQ insert O(log n), extractMin O(log n), pointer-heap insert Θ(1)","d":"all three operations are Θ(n²)"}}}}}},"c-runtime-analysis-asymptotics":{"c-runtime-analysis-asymptotics-module-1-frequency-counting":{"constant-and-rectangular-loops":{"label":"Fixed and Rectangular Nested Loops","summary":"Compare Foo1’s fixed strip with Foo2’s growing square.","cards":{"foo1-foo2-walkthrough":{"title":"Foo1 and Foo2: Fixed Width versus an n × n Rectangle"},"rectangle-animation":{"title":"Fixed Strip versus Growing Rectangle"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"count_foo1_foo2":{"title":"Derive Exact Counts for Foo1 and Foo2"}},"finalLab":{"steps":{"count_foo1_foo2":{"title":"Derive Exact Counts for Foo1 and Foo2","prompt":"Complete the four helpers in `analysis.c`. Count tuple-print calls separately from all `printf` calls. Use formulas rather than reproducing the printing loops.","hint":"Foo1 adds one newline to each group of three tuple prints. Foo2 adds one newline to each row of n tuple prints.","help":{"concept":"The exact tuple counts are `3n` and `n²`; total printf counts are `4n` and `n²+n`.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 6;\n printf(\"foo1 tuples=%lld all=%lld theta=n\\n\", foo1_tuple_prints(n), foo1_all_printf_calls(n));\n printf(\"foo2 tuples=%lld all=%lld theta=n^2\\n\", foo2_tuple_prints(n), foo2_all_printf_calls(n));\n return 0;\n}\n","solutionCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 6;\n printf(\"foo1 tuples=%lld all=%lld theta=n\\n\", foo1_tuple_prints(n), foo1_all_printf_calls(n));\n printf(\"foo2 tuples=%lld all=%lld theta=n^2\\n\", foo2_tuple_prints(n), foo2_all_printf_calls(n));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 6;\n printf(\"foo1 tuples=%lld all=%lld theta=n\\n\", foo1_tuple_prints(n), foo1_all_printf_calls(n));\n printf(\"foo2 tuples=%lld all=%lld theta=n^2\\n\", foo2_tuple_prints(n), foo2_all_printf_calls(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo1_tuple_prints(long long n);\nlong long foo1_all_printf_calls(long long n);\nlong long foo2_tuple_prints(long long n);\nlong long foo2_all_printf_calls(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo1_tuple_prints(long long n) { (void)n; return 0; }\nlong long foo1_all_printf_calls(long long n) { (void)n; return 0; }\nlong long foo2_tuple_prints(long long n) { (void)n; return 0; }\nlong long foo2_all_printf_calls(long long n) { (void)n; return 0; }\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 6;\n printf(\"foo1 tuples=%lld all=%lld theta=n\\n\", foo1_tuple_prints(n), foo1_all_printf_calls(n));\n printf(\"foo2 tuples=%lld all=%lld theta=n^2\\n\", foo2_tuple_prints(n), foo2_all_printf_calls(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo1_tuple_prints(long long n);\nlong long foo1_all_printf_calls(long long n);\nlong long foo2_tuple_prints(long long n);\nlong long foo2_all_printf_calls(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo1_tuple_prints(long long n) { return 3 * n; }\nlong long foo1_all_printf_calls(long long n) { return 4 * n; }\nlong long foo2_tuple_prints(long long n) { return n * n; }\nlong long foo2_all_printf_calls(long long n) { return n * n + n; }\n"}},"checks":[{"message":"Foo1 has exactly three tuple prints per row."},{"message":"Foo2 forms an n by n rectangle."},{"message":"Include one newline call for each Foo2 row."}]}}},"quiz":{"foo1-reason":{"title":"Why Foo1 is linear","prompt":"Why is Foo1 Θ(n) even though it contains two loops?","hint":"Ask whether the inner bound grows with n.","help":{"concept":"A fixed inner bound contributes a constant factor, so 3n is Θ(n).","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Nested loops are always linear","b":"The inner loop runs a fixed 3 times","c":"printf is constant-time only outside loops","d":"The outer loop runs once"}},"foo2-all":{"title":"Count every printf","prompt":"How many total printf calls does Foo2 make, including newlines?","hint":"There is one newline after each row.","help":{"concept":"The n² tuple prints plus n newline prints give n²+n.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"n²","b":"2n","c":"n²+n","d":"n³"}}}},"dependent-triangular-loops":{"label":"Dependent Inner Loops Form Triangles","summary":"Derive Foo3 by summing row lengths.","cards":{"foo3-walkthrough":{"title":"Foo3: Sum a Dependent Inner Loop"},"triangle-animation":{"title":"Build the Triangular Count One Row at a Time"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"count_foo3":{"title":"Count Foo3’s Triangle"}},"finalLab":{"steps":{"count_foo3":{"title":"Count Foo3’s Triangle","prompt":"Complete `foo3_tuple_prints` by accumulating each row length. Then include the `n` newline calls in `foo3_all_printf_calls`.","hint":"The inner loop runs i times for the current row.","help":{"concept":"A dependent inner loop becomes a sum over i. The exact tuple count is n(n−1)/2.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 7;\n printf(\"foo3 tuples=%lld all=%lld theta=n^2\\n\", foo3_tuple_prints(n), foo3_all_printf_calls(n));\n return 0;\n}\n","solutionCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 7;\n printf(\"foo3 tuples=%lld all=%lld theta=n^2\\n\", foo3_tuple_prints(n), foo3_all_printf_calls(n));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 7;\n printf(\"foo3 tuples=%lld all=%lld theta=n^2\\n\", foo3_tuple_prints(n), foo3_all_printf_calls(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo3_tuple_prints(long long n);\nlong long foo3_all_printf_calls(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo3_tuple_prints(long long n) {\n /* TODO: add row lengths 0 through n - 1. */\n return 0;\n}\nlong long foo3_all_printf_calls(long long n) {\n /* TODO: include one newline for every outer iteration. */\n return 0;\n}\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 7;\n printf(\"foo3 tuples=%lld all=%lld theta=n^2\\n\", foo3_tuple_prints(n), foo3_all_printf_calls(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo3_tuple_prints(long long n);\nlong long foo3_all_printf_calls(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo3_tuple_prints(long long n) {\n long long total = 0;\n for (long long i = 0; i < n; i++) {\n total += i;\n }\n return total;\n}\nlong long foo3_all_printf_calls(long long n) {\n return foo3_tuple_prints(n) + n;\n}\n"}},"checks":[{"message":"Add the current row length i to the running count."},{"message":"Add one newline for each outer-loop iteration."}]}}},"quiz":{"triangle-exact":{"title":"Exact triangular count","prompt":"What is the exact number of tuple prints in Foo3?","hint":"Write the row lengths from i=0 through i=n−1.","help":{"concept":"The sum 0+1+...+(n−1) equals n(n−1)/2.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"n²","b":"n(n−1)/2","c":"n(n+1)","d":"n−1"}},"triangle-theta":{"title":"Tight bound","prompt":"Why is n(n−1)/2 still Θ(n²)?","hint":"Expand the expression.","help":{"concept":"n(n−1)/2 = (n²−n)/2 has dominant term n²/2.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"The 1/2 factor changes only the constant","b":"Every triangle is a square","c":"The −n term becomes exponential","d":"Θ ignores n"}}}},"frequency-count-method":{"label":"The Frequency-Count Method","summary":"Trace first, derive the exact count, then classify.","cards":{"method-overview":{"title":"The Tutor-Style Frequency-Count Method"},"method-animation":{"title":"Think → Trace → Count → Sum → Simplify → Classify"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"count_patterns":{"title":"Count Three Common Loop Shapes"}},"finalLab":{"steps":{"count_patterns":{"title":"Count Three Common Loop Shapes","prompt":"Open `analysis.c`. Complete the three exact-count helpers. Use multiplication for the fixed strip and square, and the arithmetic-series formula for the triangle. Do not simulate enormous loops.","hint":"The triangle contains `0 + 1 + ... + (n - 1)` points.","help":{"concept":"Exact counts come before asymptotic labels. The functions should return `n·width`, `n²`, and `n(n−1)/2`.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"analysis.h\"\n\nint main(void) {\n const long long n = 5;\n printf(\"n=%lld\\n\", n);\n printf(\"constant=%lld\\n\", count_constant_inner(n, 3));\n printf(\"square=%lld\\n\", count_square(n));\n printf(\"triangle=%lld\\n\", count_triangle(n));\n return 0;\n}\n","solutionCode":"#include \n#include \"analysis.h\"\n\nint main(void) {\n const long long n = 5;\n printf(\"n=%lld\\n\", n);\n printf(\"constant=%lld\\n\", count_constant_inner(n, 3));\n printf(\"square=%lld\\n\", count_square(n));\n printf(\"triangle=%lld\\n\", count_triangle(n));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\n\nint main(void) {\n const long long n = 5;\n printf(\"n=%lld\\n\", n);\n printf(\"constant=%lld\\n\", count_constant_inner(n, 3));\n printf(\"square=%lld\\n\", count_square(n));\n printf(\"triangle=%lld\\n\", count_triangle(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long count_constant_inner(long long n, long long width);\nlong long count_square(long long n);\nlong long count_triangle(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\n\nlong long count_constant_inner(long long n, long long width) {\n /* TODO: exact count for n rows of fixed width. */\n return 0;\n}\n\nlong long count_square(long long n) {\n /* TODO: exact count for an n by n rectangle. */\n return 0;\n}\n\nlong long count_triangle(long long n) {\n /* TODO: exact count for row lengths 0 through n - 1. */\n return 0;\n}\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\n\nint main(void) {\n const long long n = 5;\n printf(\"n=%lld\\n\", n);\n printf(\"constant=%lld\\n\", count_constant_inner(n, 3));\n printf(\"square=%lld\\n\", count_square(n));\n printf(\"triangle=%lld\\n\", count_triangle(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long count_constant_inner(long long n, long long width);\nlong long count_square(long long n);\nlong long count_triangle(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\n\nlong long count_constant_inner(long long n, long long width) {\n return n * width;\n}\n\nlong long count_square(long long n) {\n return n * n;\n}\n\nlong long count_triangle(long long n) {\n return n * (n - 1) / 2;\n}\n"}},"checks":[{"message":"Multiply the number of rows by the fixed inner width."},{"message":"Use n times n for the rectangular pattern."},{"message":"Use the arithmetic-series formula for the triangle."}]}}},"quiz":{"fixed-inner":{"title":"Fixed inner loop","prompt":"An outer loop runs n times and its inner loop always runs 3 times. What is the tight bound?","hint":"The inner bound is a constant, not n.","help":{"concept":"The exact body count is 3n, and constant factors disappear in Θ notation.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Θ(1)","b":"Θ(log n)","c":"Θ(n)","d":"Θ(n²)"}},"sequential-rule":{"title":"Sequential blocks","prompt":"Two separate loops each run n times. How are their costs combined?","hint":"The second loop is not inside the first.","help":{"concept":"Sequential work adds: n + n = 2n = Θ(n).","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Multiply them to get n²","b":"Add them to get 2n","c":"Keep only the first loop","d":"Treat them as logarithmic"}}}},"moving-loop-bounds":{"label":"Moving Loop Bounds and Cubic Work","summary":"Analyze Foo4 and Foo4_5 with exact interval counts.","cards":{"foo4-walkthrough":{"title":"Foo4 and Foo4_5: Cubic Work with Moving Bounds"},"moving-bounds-animation":{"title":"Rectangle Plus or Minus a Triangular Correction"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"count_foo4_variants":{"title":"Count Foo4 and Foo4_5 Exactly"}},"finalLab":{"steps":{"count_foo4_variants":{"title":"Count Foo4 and Foo4_5 Exactly","prompt":"Complete all four helpers. Use the integer-interval length for Foo4 and subtract the triangular correction for Foo4_5.","hint":"For Foo4_5, sum n²−i over i=0 through n−1.","help":{"concept":"Foo4 is n(n²−n). Foo4_5 is n³−n(n−1)/2. Both are Θ(n³).","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 4;\n printf(\"foo4 tuples=%lld all=%lld theta=n^3\\n\", foo4_tuple_prints(n), foo4_all_printf_calls(n));\n printf(\"foo45 tuples=%lld all=%lld theta=n^3\\n\", foo45_tuple_prints(n), foo45_all_printf_calls(n));\n return 0;\n}\n","solutionCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 4;\n printf(\"foo4 tuples=%lld all=%lld theta=n^3\\n\", foo4_tuple_prints(n), foo4_all_printf_calls(n));\n printf(\"foo45 tuples=%lld all=%lld theta=n^3\\n\", foo45_tuple_prints(n), foo45_all_printf_calls(n));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 4;\n printf(\"foo4 tuples=%lld all=%lld theta=n^3\\n\", foo4_tuple_prints(n), foo4_all_printf_calls(n));\n printf(\"foo45 tuples=%lld all=%lld theta=n^3\\n\", foo45_tuple_prints(n), foo45_all_printf_calls(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo4_tuple_prints(long long n);\nlong long foo4_all_printf_calls(long long n);\nlong long foo45_tuple_prints(long long n);\nlong long foo45_all_printf_calls(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo4_tuple_prints(long long n) { (void)n; return 0; }\nlong long foo4_all_printf_calls(long long n) { (void)n; return 0; }\nlong long foo45_tuple_prints(long long n) { (void)n; return 0; }\nlong long foo45_all_printf_calls(long long n) { (void)n; return 0; }\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 4;\n printf(\"foo4 tuples=%lld all=%lld theta=n^3\\n\", foo4_tuple_prints(n), foo4_all_printf_calls(n));\n printf(\"foo45 tuples=%lld all=%lld theta=n^3\\n\", foo45_tuple_prints(n), foo45_all_printf_calls(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo4_tuple_prints(long long n);\nlong long foo4_all_printf_calls(long long n);\nlong long foo45_tuple_prints(long long n);\nlong long foo45_all_printf_calls(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo4_tuple_prints(long long n) { return n * (n * n - n); }\nlong long foo4_all_printf_calls(long long n) { return foo4_tuple_prints(n) + n; }\nlong long foo45_tuple_prints(long long n) { return n * n * n - n * (n - 1) / 2; }\nlong long foo45_all_printf_calls(long long n) { return foo45_tuple_prints(n) + n; }\n"}},"checks":[{"message":"Count n rows of width n²−n for Foo4."},{"message":"Subtract the triangular lower-bound correction for Foo4_5."},{"message":"Include one newline for each outer-loop row."}]}}},"quiz":{"foo4-row":{"title":"One Foo4 row","prompt":"How many tuple prints occur in one Foo4 row?","hint":"Count integers from n through n²−1.","help":{"concept":"The interval length is n²−n.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"n","b":"n²","c":"n²−n","d":"n³−n²"}},"foo45-row":{"title":"One Foo4_5 row","prompt":"How many tuple prints occur in Foo4_5 row i?","hint":"The loop starts at i and stops before n².","help":{"concept":"The interval i through n²−1 contains n²−i values.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"i","b":"n²−i","c":"n−i","d":"n²+i"}}}},"sequential-loops-and-linear-recursion":{"label":"Sequential Loops and Linear Recursion","summary":"Finish the runtime-analysis set with Foo5 and Foo6.","cards":{"foo5-foo6-walkthrough":{"title":"Foo5 and Foo6: Add Sequential Work and Trace a Call Chain"},"sequential-recursion-animation":{"title":"Add Blocks; Follow Recursive Calls"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"count_foo5_foo6":{"title":"Count Sequential Loops and a Recursive Chain"}},"finalLab":{"steps":{"count_foo5_foo6":{"title":"Count Sequential Loops and a Recursive Chain","prompt":"Complete the five helpers. Keep tuple prints, total calls, and stack depth distinct.","hint":"Foo6 makes one extra base-case call after the last printed pair.","help":{"concept":"Sequential loops add. A single recursive call per level forms a chain with n printed levels and one additional base-case call.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 8;\n printf(\"foo5 tuples=%lld all=%lld\\n\", foo5_tuple_prints(n), foo5_all_printf_calls(n));\n printf(\"foo6 tuples=%lld calls=%lld stack=%lld\\n\", foo6_tuple_prints(n), foo6_total_calls(n), foo6_stack_depth(n));\n return 0;\n}\n","solutionCode":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 8;\n printf(\"foo5 tuples=%lld all=%lld\\n\", foo5_tuple_prints(n), foo5_all_printf_calls(n));\n printf(\"foo6 tuples=%lld calls=%lld stack=%lld\\n\", foo6_tuple_prints(n), foo6_total_calls(n), foo6_stack_depth(n));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 8;\n printf(\"foo5 tuples=%lld all=%lld\\n\", foo5_tuple_prints(n), foo5_all_printf_calls(n));\n printf(\"foo6 tuples=%lld calls=%lld stack=%lld\\n\", foo6_tuple_prints(n), foo6_total_calls(n), foo6_stack_depth(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo5_tuple_prints(long long n);\nlong long foo5_all_printf_calls(long long n);\nlong long foo6_tuple_prints(long long n);\nlong long foo6_total_calls(long long n);\nlong long foo6_stack_depth(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo5_tuple_prints(long long n) { (void)n; return 0; }\nlong long foo5_all_printf_calls(long long n) { (void)n; return 0; }\nlong long foo6_tuple_prints(long long n) { (void)n; return 0; }\nlong long foo6_total_calls(long long n) { (void)n; return 0; }\nlong long foo6_stack_depth(long long n) { (void)n; return 0; }\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"analysis.h\"\nint main(void) {\n const long long n = 8;\n printf(\"foo5 tuples=%lld all=%lld\\n\", foo5_tuple_prints(n), foo5_all_printf_calls(n));\n printf(\"foo6 tuples=%lld calls=%lld stack=%lld\\n\", foo6_tuple_prints(n), foo6_total_calls(n), foo6_stack_depth(n));\n return 0;\n}\n"},"analysis_h":{"content":"#ifndef ANALYSIS_H\n#define ANALYSIS_H\nlong long foo5_tuple_prints(long long n);\nlong long foo5_all_printf_calls(long long n);\nlong long foo6_tuple_prints(long long n);\nlong long foo6_total_calls(long long n);\nlong long foo6_stack_depth(long long n);\n#endif\n"},"analysis_c":{"content":"#include \"analysis.h\"\nlong long foo5_tuple_prints(long long n) { return n + n; }\nlong long foo5_all_printf_calls(long long n) { return foo5_tuple_prints(n) + 2; }\nlong long foo6_tuple_prints(long long n) { return n; }\nlong long foo6_total_calls(long long n) { return n + 1; }\nlong long foo6_stack_depth(long long n) { return n; }\n"}},"checks":[{"message":"Add the two sequential Foo5 loop counts."},{"message":"Include Foo6’s final base-case call."},{"message":"Report linear tuple prints and stack depth."}]}}},"quiz":{"sequential-cost":{"title":"Sequential loops","prompt":"Two separate n-iteration loops have what combined tight bound?","hint":"Add the two blocks.","help":{"concept":"n+n=2n, and constant factors do not change Θ.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Θ(1)","b":"Θ(n)","c":"Θ(n²)","d":"Θ(2ⁿ)"}},"foo6-base":{"title":"Foo6 base case","prompt":"Does the call Foo6(n,n,n) print a pair?","hint":"Read the order of statements.","help":{"concept":"The base-case test runs first, so the final call returns without printing.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Yes, before testing the base case","b":"Yes, because n is included","c":"No, it returns before printing","d":"Only when n is even"}}}}},"c-runtime-analysis-asymptotics-module-2-limit-method":{"big-o-omega-theta-by-limits":{"label":"Big-O, Big-Ω, and Big-Θ by Limits","summary":"Use one ratio and interpret its limiting outcome.","cards":{"limit-rule":{"title":"Classify Growth with the Ratio Limit"},"limit-outcomes-animation":{"title":"Three Possible Ratio Outcomes"},"check-understanding":{"title":"Check Your Understanding"}},"quiz":{"limit-zero":{"title":"Ratio equals zero","prompt":"If lim f(n)/g(n)=0, which requested classification is correct?","hint":"f becomes small relative to g.","help":{"concept":"A zero ratio means f grows strictly slower, so f=O(g).","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=Ω(g)","b":"f=Θ(g)","c":"f=O(g)","d":"g=O(f) only"}},"limit-constant":{"title":"Positive finite ratio","prompt":"If lim f(n)/g(n)=3/2, what follows?","hint":"A positive finite constant indicates matching rates.","help":{"concept":"Constant-factor differences are exactly what Θ ignores.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=Θ(g)","b":"f=O(1)","c":"f=Ω(2ⁿ)","d":"No asymptotic relation"}},"limit-infinity":{"title":"Ratio diverges","prompt":"If lim f(n)/g(n)=∞, what follows?","hint":"The numerator dominates the denominator.","help":{"concept":"An infinite ratio means f grows strictly faster than g.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=O(g)","b":"f=Ω(g)","c":"f=Θ(g)","d":"f=Θ(1)"}}}},"exponential-limits-and-growth-order":{"label":"Exponential Comparisons and Growth Ordering","summary":"Finish the limit problems and order the major growth classes.","cards":{"exponential-and-ordering":{"title":"Exponential Limits and the Standard Growth Hierarchy"},"growth-order-animation":{"title":"Watch Growth Classes Separate"},"check-understanding":{"title":"Check Your Understanding"}},"quiz":{"exp-poly":{"title":"Exponential over polynomial","prompt":"What is the relation between f=2ⁿ and g=10n²?","hint":"Exponentials eventually dominate fixed-degree polynomials.","help":{"concept":"The ratio 2ⁿ/(10n²) tends to infinity.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=O(g)","b":"f=Θ(g)","c":"f=Ω(g)","d":"Both are logarithmic"}},"two-vs-four":{"title":"Subtract exponents","prompt":"What is 2ⁿ relative to 2²ⁿ?","hint":"Simplify the ratio by subtracting exponents.","help":{"concept":"2ⁿ/2²ⁿ=2⁻ⁿ tends to zero.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Θ","b":"O","c":"Ω","d":"Equal for every n"}},"correct-order":{"title":"Growth order","prompt":"Which order is correct from slowest to fastest?","hint":"Use logarithm, powers, polynomial, exponential, factorial.","help":{"concept":"The standard hierarchy places factorial last and logarithm first.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"n < log n < n² < 2ⁿ","b":"log n < √n < n < n log n < n² < 2ⁿ < n!","c":"n! < 2ⁿ < n² < n","d":"√n < log n < n! < n"}},"factorial-reason":{"title":"Why factorial wins","prompt":"Why does n! eventually outgrow 2ⁿ?","hint":"Compare the factors in the product n!.","help":{"concept":"As n grows, multiplying by 3,4,5,... beats multiplying by 2 at every step.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Factorials are constants","b":"Most later factors in n! exceed 2","c":"2ⁿ decreases","d":"n! equals n²"}}}},"limit-method-review":{"label":"Limit-Method Review Lab","summary":"Use sampled ratios to support, not replace, symbolic conclusions.","cards":{"limit-review":{"title":"Limit-Method Review: Compute, Interpret, State"},"limit-review-animation":{"title":"A Repeatable Limit Decision Flow"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"sample_ratios":{"title":"Sample Three Ratios in C"}},"finalLab":{"steps":{"sample_ratios":{"title":"Sample Three Ratios in C","prompt":"Complete the three ratio functions. The output should numerically support the symbolic limits without replacing them.","hint":"Rewrite the exponential ratio as a repeated factor of 2/3.","help":{"concept":"Numerical values should move toward the limits derived in the lesson: 1.5, 0, and 0.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"ratios.h\"\nint main(void) {\n printf(\"poly_ratio_n1000=%.6f\\n\", polynomial_ratio(1000.0));\n printf(\"degree_ratio_n1000=%.6f\\n\", lower_degree_ratio(1000.0));\n printf(\"exp_ratio_n20=%.6f\\n\", exponential_ratio(20));\n return 0;\n}\n","solutionCode":"#include \n#include \"ratios.h\"\nint main(void) {\n printf(\"poly_ratio_n1000=%.6f\\n\", polynomial_ratio(1000.0));\n printf(\"degree_ratio_n1000=%.6f\\n\", lower_degree_ratio(1000.0));\n printf(\"exp_ratio_n20=%.6f\\n\", exponential_ratio(20));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"ratios.h\"\nint main(void) {\n printf(\"poly_ratio_n1000=%.6f\\n\", polynomial_ratio(1000.0));\n printf(\"degree_ratio_n1000=%.6f\\n\", lower_degree_ratio(1000.0));\n printf(\"exp_ratio_n20=%.6f\\n\", exponential_ratio(20));\n return 0;\n}\n"},"ratios_h":{"content":"#ifndef RATIOS_H\n#define RATIOS_H\ndouble polynomial_ratio(double n);\ndouble lower_degree_ratio(double n);\ndouble exponential_ratio(int n);\n#endif\n"},"ratios_c":{"content":"#include \"ratios.h\"\ndouble polynomial_ratio(double n) { (void)n; return 0.0; }\ndouble lower_degree_ratio(double n) { (void)n; return 0.0; }\ndouble exponential_ratio(int n) { (void)n; return 0.0; }\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"ratios.h\"\nint main(void) {\n printf(\"poly_ratio_n1000=%.6f\\n\", polynomial_ratio(1000.0));\n printf(\"degree_ratio_n1000=%.6f\\n\", lower_degree_ratio(1000.0));\n printf(\"exp_ratio_n20=%.6f\\n\", exponential_ratio(20));\n return 0;\n}\n"},"ratios_h":{"content":"#ifndef RATIOS_H\n#define RATIOS_H\ndouble polynomial_ratio(double n);\ndouble lower_degree_ratio(double n);\ndouble exponential_ratio(int n);\n#endif\n"},"ratios_c":{"content":"#include \"ratios.h\"\ndouble polynomial_ratio(double n) { return (3.0 * n * n + 7.0 * n) / (2.0 * n * n); }\ndouble lower_degree_ratio(double n) { return (2.0 * n * n * n * n - 3.0 * n * n + 7.0) / (n * n * n * n * n); }\ndouble exponential_ratio(int n) {\n double ratio = 1.0;\n for (int i = 0; i < n; i++) ratio *= 2.0 / 3.0;\n return ratio;\n}\n"}},"checks":[{"message":"Build the polynomial numerator explicitly."},{"message":"Use n⁵ in the lower-degree comparison denominator."},{"message":"Build (2/3)^n as repeated multiplication."}]}}},"quiz":{"sampling-proof":{"title":"Sampling versus proof","prompt":"What role does the C sampling lab play?","hint":"Finite samples cannot establish an infinite-limit claim.","help":{"concept":"Sampling is a useful sanity check; algebra and limits provide the proof.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"It proves the limit for all n","b":"It checks the expected numerical trend","c":"It replaces asymptotic notation","d":"It makes constants irrelevant"}},"ratio-direction":{"title":"Keep the ratio direction","prompt":"Why must you compute f/g in the order requested?","hint":"Compare L with its reciprocal.","help":{"concept":"If f/g tends to 0, then g/f tends to infinity.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Because addition is not commutative","b":"Because reversing the ratio swaps zero and infinity","c":"Because g/f is undefined","d":"Because Θ uses subtraction"}}}},"polynomial-and-log-limit-comparisons":{"label":"Polynomial and Logarithmic Limit Comparisons","summary":"Work through the handout’s first eight ratio problems.","cards":{"worked-limits-one-eight":{"title":"Worked Limit Comparisons: Constants, Polynomials, and Logs"},"polynomial-log-animation":{"title":"Cancel, Normalize, or Differentiate"},"check-understanding":{"title":"Check Your Understanding"}},"quiz":{"poly-same-degree":{"title":"Same polynomial degree","prompt":"For f=3n²+7n and g=2n², what is the relation?","hint":"Divide numerator and denominator by n².","help":{"concept":"The ratio tends to 3/2, a positive finite constant.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=O(g) only","b":"f=Ω(g) only","c":"f=Θ(g)","d":"No relation"}},"lower-degree":{"title":"Lower numerator degree","prompt":"For f=2n⁴−3n²+7 and g=n⁵, what is the relation?","hint":"Compare the highest polynomial degrees.","help":{"concept":"The ratio tends to 0 because degree 4 grows more slowly than degree 5.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=O(g)","b":"f=Ω(g)","c":"f=Θ(g)","d":"f=Θ(2ⁿ)"}},"log-square":{"title":"Polynomial versus log","prompt":"For f=n and g=(log n)², what is the relation?","hint":"Any positive power of n outruns a fixed log power.","help":{"concept":"The ratio n/(log n)² tends to infinity.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=O(g)","b":"f=Θ(g)","c":"f=Ω(g)","d":"Both are constant"}},"nlog-over-log":{"title":"Cancel the log factor","prompt":"For f=n log n+n and g=log n, what is the relation?","hint":"Divide each numerator term by log n.","help":{"concept":"The ratio is n+n/log n, which tends to infinity.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"f=O(g)","b":"f=Ω(g)","c":"f=Θ(g)","d":"f=Θ(1)"}}}}},"c-runtime-analysis-asymptotics-module-3-inequality-proofs":{"inequality-definition-recipe-and-big-o":{"label":"Big-O Proofs from the Definition","summary":"Prove two upper bounds and repair an invalid threshold.","cards":{"big-o-proofs":{"title":"Use the Inequality Definition to Prove Big-O"},"big-o-proof-animation":{"title":"Choose Constants, Then Validate the Threshold"},"check-understanding":{"title":"Check Your Understanding"}},"quiz":{"poly-big-o-constants":{"title":"Valid polynomial constants","prompt":"Which pair proves 10n²=O(n³)?","hint":"Substitute the constants into 10n²≤cn³.","help":{"concept":"With c=10, the inequality reduces to 1≤n.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"c=1,n₀=1","b":"c=10,n₀=1","c":"c=0,n₀=1","d":"c=1,n₀=0 only"}},"exp-counterexample":{"title":"Check n₀","prompt":"Why is c=1,n₀=2 invalid for n²≤2ⁿ?","hint":"Test the next few integers.","help":{"concept":"At n=3, 9≤8 is false.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"n=2 fails","b":"n=3 fails","c":"n=4 fails","d":"c must be negative"}},"big-o-nonunique":{"title":"Constants are not unique","prompt":"What is required of Big-O constants?","hint":"The definition asks for existence, not optimality.","help":{"concept":"Big-O proofs only need one valid positive c and one valid threshold n₀.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"They must be the smallest possible","b":"Any positive pair that makes the inequality hold eventually is enough","c":"c must equal 1","d":"n₀ must equal 0"}}}},"prove-big-omega-bounds":{"label":"A Big-Ω Inequality Proof","summary":"Prove the cubic eventually stays above the quadratic expression.","cards":{"omega-proof":{"title":"Prove a Big-Ω Lower Bound"},"omega-proof-animation":{"title":"Build a Lower-Bound Inequality Chain"},"check-understanding":{"title":"Check Your Understanding"}},"quiz":{"omega-direction":{"title":"Ω inequality direction","prompt":"Which inequality matches T(n)=Ω(g(n))?","hint":"Ω is a lower bound on T.","help":{"concept":"A positive multiple of g must lie below T eventually.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"0≤T(n)≤cg(n)","b":"0≤cg(n)≤T(n)","c":"T(n)=g(n) for all n","d":"cg(n)≤0"}},"omega-threshold":{"title":"Why n₀=2?","prompt":"Why does the proof choose n₀=2?","hint":"Inspect the final comparison 3n²≤2n³.","help":{"concept":"Dividing by n² gives 3≤2n, which is true for n≥2.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Because n²+n+1 is negative before 2","b":"Because 3≤2n begins at n=2","c":"Because c must equal n₀","d":"Because cubic functions start at 2"}},"omega-middle":{"title":"Purpose of 3n²","prompt":"Why introduce 3n² in the proof?","hint":"The middle expression should connect the two sides.","help":{"concept":"Bounding all three terms by n² makes the comparison simple.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"To make the expression exponential","b":"To create an easy upper bound for n²+n+1 that still lies below 2n³","c":"To change Ω into O","d":"To eliminate n₀"}}}},"prove-big-theta-bounds":{"label":"A Big-Θ Inequality Proof","summary":"Prove a cubic polynomial has tight cubic growth.","cards":{"theta-proof":{"title":"Prove a Two-Sided Big-Θ Bound"},"theta-proof-animation":{"title":"Squeeze a Polynomial Between Two Cubics"},"guided-lab":{"title":"Guided C Lab"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"verify_theta_bounds":{"title":"Sanity-Check the Θ Constants in C"}},"finalLab":{"steps":{"verify_theta_bounds":{"title":"Sanity-Check the Θ Constants in C","prompt":"Complete `theta_bounds_hold`. Avoid floating point by multiplying the lower inequality by 2. The finite test supports the algebraic proof but does not replace it.","hint":"Check `n³ <= 2T(n)` for the lower bound and `T(n) <= 2n³` for the upper bound.","help":{"concept":"The chosen constants are c₁=1/2, c₂=2, and n₀=7.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"bounds.h\"\nint main(void) {\n int valid = 1;\n for (long long n = 7; n <= 50; n++) {\n if (!theta_bounds_hold(n)) valid = 0;\n }\n printf(\"n0=7\\nchecked_through=50\\nstatus=%s\\n\", valid ? \"valid\" : \"invalid\");\n return 0;\n}\n","solutionCode":"#include \n#include \"bounds.h\"\nint main(void) {\n int valid = 1;\n for (long long n = 7; n <= 50; n++) {\n if (!theta_bounds_hold(n)) valid = 0;\n }\n printf(\"n0=7\\nchecked_through=50\\nstatus=%s\\n\", valid ? \"valid\" : \"invalid\");\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"bounds.h\"\nint main(void) {\n int valid = 1;\n for (long long n = 7; n <= 50; n++) {\n if (!theta_bounds_hold(n)) valid = 0;\n }\n printf(\"n0=7\\nchecked_through=50\\nstatus=%s\\n\", valid ? \"valid\" : \"invalid\");\n return 0;\n}\n"},"bounds_h":{"content":"#ifndef BOUNDS_H\n#define BOUNDS_H\nint theta_bounds_hold(long long n);\n#endif\n"},"bounds_c":{"content":"#include \"bounds.h\"\nint theta_bounds_hold(long long n) {\n (void)n;\n /* TODO: verify (1/2)n^3 <= T(n) <= 2n^3 without floating point. */\n return 0;\n}\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"bounds.h\"\nint main(void) {\n int valid = 1;\n for (long long n = 7; n <= 50; n++) {\n if (!theta_bounds_hold(n)) valid = 0;\n }\n printf(\"n0=7\\nchecked_through=50\\nstatus=%s\\n\", valid ? \"valid\" : \"invalid\");\n return 0;\n}\n"},"bounds_h":{"content":"#ifndef BOUNDS_H\n#define BOUNDS_H\nint theta_bounds_hold(long long n);\n#endif\n"},"bounds_c":{"content":"#include \"bounds.h\"\nint theta_bounds_hold(long long n) {\n const long long cube = n * n * n;\n const long long t = cube - 3 * n * n - n + 1;\n const int lower_ok = cube <= 2 * t;\n const int upper_ok = t <= 2 * cube;\n return n >= 7 && t >= 0 && lower_ok && upper_ok;\n}\n"}},"checks":[{"message":"Encode the lower bound without floating point."},{"message":"Encode the upper bound."},{"message":"Respect the proven threshold n₀=7."}]}}},"quiz":{"theta-needs-both":{"title":"Two-sided requirement","prompt":"What must a Θ proof establish?","hint":"Θ is a tight bound.","help":{"concept":"T must eventually stay between c₁g and c₂g.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Only an upper bound","b":"Only a lower bound","c":"Both lower and upper constant multiples after one threshold","d":"Exact equality for every n"}},"theta-small-negative":{"title":"Why a threshold?","prompt":"Why can the proof ignore small n where T(n) is negative?","hint":"Read the quantifier in the definition.","help":{"concept":"A finite prefix does not affect eventual growth.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Negative values are rounded to zero","b":"Asymptotic definitions only require the inequality for n≥n₀","c":"Θ applies only to even n","d":"c₁ may be negative"}}}},"theta-equivalence-review":{"label":"Θ Equivalence: True or False","summary":"Decide when two expressions describe the same growth class.","cards":{"theta-true-false":{"title":"Θ-Notation: Decide Whether the Classes Match"},"theta-equivalence-animation":{"title":"Strip Constants and Lower-Order Terms"},"check-understanding":{"title":"Check Your Understanding"}},"quiz":{"theta-a":{"title":"n² and n²+7","prompt":"Is Θ(n²)=Θ(n²+7)?","hint":"Compare dominant terms or take a ratio.","help":{"concept":"The added constant is lower order.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"True","b":"False"}},"theta-b":{"title":"n² and 7n²","prompt":"Is Θ(n²)=Θ(7n²)?","hint":"Compare dominant terms or take a ratio.","help":{"concept":"A positive constant multiplier does not change Θ.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"True","b":"False"}},"theta-c":{"title":"7n²+18 and n²","prompt":"Is Θ(7n²+18)=Θ(n²)?","hint":"Compare dominant terms or take a ratio.","help":{"concept":"The quadratic term dominates the constant.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"True","b":"False"}},"theta-d":{"title":"n²+n and n²","prompt":"Is Θ(n²+n)=Θ(n²)?","hint":"Compare dominant terms or take a ratio.","help":{"concept":"The linear term is lower order.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"True","b":"False"}},"theta-e":{"title":"n² and n³","prompt":"Is Θ(n²)=Θ(n³)?","hint":"Compare dominant terms or take a ratio.","help":{"concept":"The ratio n²/n³ tends to zero.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"True","b":"False"}}}}},"c-runtime-analysis-asymptotics-module-4-capstone":{"runtime-analysis-capstone":{"label":"Runtime Analysis Capstone","summary":"Combine exact counting, Θ classification, and a formal bound.","cards":{"capstone-brief":{"title":"Capstone: Analyze New C Fragments from Exact Count to Formal Bound"},"capstone-animation":{"title":"Trace → Exact Formula → Θ → Proof"},"capstone-project":{"title":"Cumulative C Capstone"},"check-understanding":{"title":"Check Your Understanding"}},"projectSteps":{"derive_exact_counts":{"title":"Part 1: Derive Exact Counts"},"classify_dominant_terms":{"title":"Part 2: Classify the Dominant Terms"},"verify_new_theta_proof":{"title":"Part 3: Verify Explicit Θ Constants"}},"finalLab":{"steps":{"derive_exact_counts":{"title":"Part 1: Derive Exact Counts","prompt":"Implement the three exact count functions in `capstone.c`. Do not return only the dominant term.","hint":"Bar2 has row lengths n, n−1, ..., 1.","help":{"concept":"Exact counts preserve all terms and constant factors before asymptotic simplification.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"capstone.h\"\nint main(void) {\n const long long n = 6;\n printf(\"bar1=%lld\\n\", bar1_count(n));\n printf(\"bar2=%lld\\n\", bar2_count(n));\n printf(\"bar3=%lld\\n\", bar3_count(n));\n return 0;\n}\n","solutionCode":"#include \n#include \"capstone.h\"\nint main(void) {\n const long long n = 6;\n printf(\"bar1=%lld\\n\", bar1_count(n));\n printf(\"bar2=%lld\\n\", bar2_count(n));\n printf(\"bar3=%lld\\n\", bar3_count(n));\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"capstone.h\"\nint main(void) {\n const long long n = 6;\n printf(\"bar1=%lld\\n\", bar1_count(n));\n printf(\"bar2=%lld\\n\", bar2_count(n));\n printf(\"bar3=%lld\\n\", bar3_count(n));\n return 0;\n}\n"},"capstone_h":{"content":"#ifndef CAPSTONE_H\n#define CAPSTONE_H\nlong long bar1_count(long long n);\nlong long bar2_count(long long n);\nlong long bar3_count(long long n);\n#endif\n"},"capstone_c":{"content":"#include \"capstone.h\"\nlong long bar1_count(long long n) { (void)n; return 0; }\nlong long bar2_count(long long n) { (void)n; return 0; }\nlong long bar3_count(long long n) { (void)n; return 0; }\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"capstone.h\"\nint main(void) {\n const long long n = 6;\n printf(\"bar1=%lld\\n\", bar1_count(n));\n printf(\"bar2=%lld\\n\", bar2_count(n));\n printf(\"bar3=%lld\\n\", bar3_count(n));\n return 0;\n}\n"},"capstone_h":{"content":"#ifndef CAPSTONE_H\n#define CAPSTONE_H\nlong long bar1_count(long long n);\nlong long bar2_count(long long n);\nlong long bar3_count(long long n);\n#endif\n"},"capstone_c":{"content":"#include \"capstone.h\"\nlong long bar1_count(long long n) { return 5 * n; }\nlong long bar2_count(long long n) { return n * (n + 1) / 2; }\nlong long bar3_count(long long n) { return n + n * n; }\n"}},"checks":[{"message":"Bar1 has fixed width 5."},{"message":"Bar2 uses the sum 1 through n."},{"message":"Bar3 adds its sequential blocks."}]},"classify_dominant_terms":{"title":"Part 2: Classify the Dominant Terms","prompt":"Replace each TODO string with the tight Θ class implied by the exact formulas from Part 1.","hint":"Expand Bar2 and identify the highest power; for Bar3, the larger sequential block dominates.","help":{"concept":"5n is linear. n(n+1)/2 and n+n² are quadratic.","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"classify.h\"\nint main(void) {\n printf(\"bar1=%s\\n\", bar1_theta());\n printf(\"bar2=%s\\n\", bar2_theta());\n printf(\"bar3=%s\\n\", bar3_theta());\n return 0;\n}\n","solutionCode":"#include \n#include \"classify.h\"\nint main(void) {\n printf(\"bar1=%s\\n\", bar1_theta());\n printf(\"bar2=%s\\n\", bar2_theta());\n printf(\"bar3=%s\\n\", bar3_theta());\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"classify.h\"\nint main(void) {\n printf(\"bar1=%s\\n\", bar1_theta());\n printf(\"bar2=%s\\n\", bar2_theta());\n printf(\"bar3=%s\\n\", bar3_theta());\n return 0;\n}\n"},"classify_h":{"content":"#ifndef CLASSIFY_H\n#define CLASSIFY_H\nconst char *bar1_theta(void);\nconst char *bar2_theta(void);\nconst char *bar3_theta(void);\n#endif\n"},"classify_c":{"content":"#include \"classify.h\"\nconst char *bar1_theta(void) { return \"TODO\"; }\nconst char *bar2_theta(void) { return \"TODO\"; }\nconst char *bar3_theta(void) { return \"TODO\"; }\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"classify.h\"\nint main(void) {\n printf(\"bar1=%s\\n\", bar1_theta());\n printf(\"bar2=%s\\n\", bar2_theta());\n printf(\"bar3=%s\\n\", bar3_theta());\n return 0;\n}\n"},"classify_h":{"content":"#ifndef CLASSIFY_H\n#define CLASSIFY_H\nconst char *bar1_theta(void);\nconst char *bar2_theta(void);\nconst char *bar3_theta(void);\n#endif\n"},"classify_c":{"content":"#include \"classify.h\"\nconst char *bar1_theta(void) { return \"Theta(n)\"; }\nconst char *bar2_theta(void) { return \"Theta(n^2)\"; }\nconst char *bar3_theta(void) { return \"Theta(n^2)\"; }\n"}},"checks":[{"message":"Return the linear class for Bar1."},{"message":"Return the quadratic class for Bar2 and Bar3."}]},"verify_new_theta_proof":{"title":"Part 3: Verify Explicit Θ Constants","prompt":"Implement the finite checker for the proposed constants c₁=6, c₂=11, and n₀=1. Then relate each inequality to the algebraic proof in the lesson.","hint":"Compute T(n), then compare it with 6n² and 11n².","help":{"concept":"For n≥1, the lower bound is immediate and the upper bound follows from 3n≤3n² and 2≤2n².","hint_1":"Work from the traced values to an exact count before simplifying.","hint_2":"Run the supplied test harness after each focused change."},"starterCode":"#include \n#include \"proof.h\"\nint main(void) {\n printf(\"c1=6 c2=11 n0=1\\n\");\n printf(\"n=1 %s\\n\", theta_proof_holds(1) ? \"valid\" : \"invalid\");\n printf(\"n=25 %s\\n\", theta_proof_holds(25) ? \"valid\" : \"invalid\");\n return 0;\n}\n","solutionCode":"#include \n#include \"proof.h\"\nint main(void) {\n printf(\"c1=6 c2=11 n0=1\\n\");\n printf(\"n=1 %s\\n\", theta_proof_holds(1) ? \"valid\" : \"invalid\");\n printf(\"n=25 %s\\n\", theta_proof_holds(25) ? \"valid\" : \"invalid\");\n return 0;\n}\n","starterFiles":{"main_c":{"content":"#include \n#include \"proof.h\"\nint main(void) {\n printf(\"c1=6 c2=11 n0=1\\n\");\n printf(\"n=1 %s\\n\", theta_proof_holds(1) ? \"valid\" : \"invalid\");\n printf(\"n=25 %s\\n\", theta_proof_holds(25) ? \"valid\" : \"invalid\");\n return 0;\n}\n"},"proof_h":{"content":"#ifndef PROOF_H\n#define PROOF_H\nint theta_proof_holds(long long n);\n#endif\n"},"proof_c":{"content":"#include \"proof.h\"\nint theta_proof_holds(long long n) {\n (void)n;\n /* TODO: verify 6n^2 <= 6n^2+3n+2 <= 11n^2 for n >= 1. */\n return 0;\n}\n"}},"solutionFiles":{"main_c":{"content":"#include \n#include \"proof.h\"\nint main(void) {\n printf(\"c1=6 c2=11 n0=1\\n\");\n printf(\"n=1 %s\\n\", theta_proof_holds(1) ? \"valid\" : \"invalid\");\n printf(\"n=25 %s\\n\", theta_proof_holds(25) ? \"valid\" : \"invalid\");\n return 0;\n}\n"},"proof_h":{"content":"#ifndef PROOF_H\n#define PROOF_H\nint theta_proof_holds(long long n);\n#endif\n"},"proof_c":{"content":"#include \"proof.h\"\nint theta_proof_holds(long long n) {\n if (n < 1) return 0;\n const long long n2 = n * n;\n const long long t = 6 * n2 + 3 * n + 2;\n return 6 * n2 <= t && t <= 11 * n2;\n}\n"}},"checks":[{"message":"Reject values before n₀."},{"message":"Check the lower bound."},{"message":"Check the upper bound."}]}}},"quiz":{"capstone-method":{"title":"Capstone workflow","prompt":"Which sequence best matches the course method?","hint":"Recall the course title animation.","help":{"concept":"The method makes work visible first and formalizes the bound last.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Guess Θ → skip exact count → test one n","b":"Trace → exact count → simplify → classify → prove","c":"Differentiate every loop","d":"Multiply all visible loops"}},"bar2-shape":{"title":"Bar2 shape","prompt":"What geometric shape represents Bar2’s row lengths?","hint":"Rows shrink from n to 1.","help":{"concept":"The sum n+(n−1)+...+1 forms a triangle.","hint_1":"Trace a small input or simplify the exact expression before choosing.","hint_2":"Check whether the work adds, multiplies, or forms a changing sum."},"options":{"a":"Constant strip","b":"Triangle","c":"Cube","d":"Single point"}}}}}},"git-foundations":{"git-foundations-module-1-start-tracking":{"configure-and-initialize-a-repository":{"label":"Initialize the Community Project Repository","summary":"Turn a two-file folder into a repository on main and configure a repository-local identity.","cards":{"sketch0":{"title":"An Ordinary Folder Becomes a Repository"},"sketch1":{"title":"Repository Metadata Stays Behind the Scenes"},"sketch2":{"title":"Identity Belongs to This Repository"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_configure_and_initialize_a_repository_sketch0":{"title":"Initialize the Community Project","prompt":"The terminal opens inside `community-project/`. The folder contains only `README.md` and `schedule.txt`, and it is not a Git repository yet. Initialize the current folder as a repository whose first branch is `main`. Do not edit or stage either file.","hint":"Create repository metadata in the current folder and name the first branch `main`.","help":{"concept":"`git init -b main` creates the hidden `.git` metadata directory in the current folder and chooses `main` as the first branch. It does not edit, stage, or commit the project files.","hint_1":"The terminal is already at the project root, so no `cd` command is needed.","hint_2":"The result should be a repository with zero commits and two untracked files."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git init -b main","instructions":"The terminal opens inside `community-project/`. The folder contains only `README.md` and `schedule.txt`, and it is not a Git repository yet. Initialize the current folder as a repository whose first branch is `main`. Do not edit or stage either file.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you turn the current folder into a repository whose first branch is `main`?"}}}},"try_configure_and_initialize_a_repository_sketch1":{"title":"Store the Local Author Name","prompt":"The repository now exists. Store the supplied author name `ZoeSkoul Learner` in this repository only. Do not change machine-wide Git settings.","hint":"Use repository-local configuration for the exact supplied name.","help":{"concept":"`git config --local user.name \"ZoeSkoul Learner\"` stores the author name inside this repository. `--local` prevents the course workspace from changing Git settings outside this project.","hint_1":"Keep quotation marks around the name because it contains a space.","hint_2":"Do not use `--global`."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git config --local user.name \"ZoeSkoul Learner\"","instructions":"The repository now exists. Store the supplied author name `ZoeSkoul Learner` in this repository only. Do not change machine-wide Git settings.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you store the supplied author name in this repository only?"}}}},"try_configure_and_initialize_a_repository_sketch2":{"title":"Complete and Verify the Local Identity","prompt":"Store `learner@zoeskoul.local` as the repository-local author email. Then read the local configuration and confirm that both the supplied name and email are present.","hint":"Add the email in the same local scope, then inspect that scope.","help":{"concept":"`git config --local user.email VALUE` stores the email for this repository. `git config --local --list` reads the local settings so you can verify both identity values before the first commit.","hint_1":"Use the exact email `learner@zoeskoul.local`.","hint_2":"The verification output should include both `user.name` and `user.email`."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git config --local user.email \"learner@zoeskoul.local\"\ngit config --local --list","instructions":"Store `learner@zoeskoul.local` as the repository-local author email. Then read the local configuration and confirm that both the supplied name and email are present.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you store the supplied local email?"},"1":{"message":"Did you read the repository-local configuration to verify both values?"}}}}},"practice":{"single-choice-1":{"title":"Repository-Local Identity","prompt":"Why does this course use `git config --local` for the supplied author identity?","hint":"Choose the scope that changes only the current repository, not every repository on the computer.","help":{"concept":"Turn an ordinary project folder into a Git repository on `main`, inspect the metadata Git created, and keep the author identity local to that repository.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"It changes the identity only inside the current repository.","b":"It deletes any existing project history.","c":"It stages every file in the project.","d":"It changes the contents of the project files."}},"single-choice-2":{"title":"Repository Initialization","prompt":"What command is used to initialize a new Git repository?","hint":"Look for the Git command that creates repository metadata in an ordinary folder.","help":{"concept":"Turn an ordinary project folder into a Git repository on `main`, inspect the metadata Git created, and keep the author identity local to that repository.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"git init","b":"git start","c":"git create","d":"git new"}},"drag-reorder-1":{"title":"Order the First Repository Setup","prompt":"Arrange the setup steps in an order that can actually work.","hint":"Start with the state that must exist before the next action can make sense.","help":{"concept":"Turn an ordinary project folder into a Git repository on `main`, inspect the metadata Git created, and keep the author identity local to that repository.","hint_1":"Track how the project moves from working files to a proposed snapshot and then to history.","hint_2":"Read the ordered steps as one continuous repository story."},"tokens":{"t1":"Initialize the project folder as a repository","t2":"Store the repository-local author identity","t3":"Inspect the current repository state"}},"fill-blank-choice-1":{"title":"Git Identity Configuration","prompt":"Complete the command to set the local Git user name: `git config --local user.name [blank1]`","hint":"Choose the term or symbol that matches the exact state described, not a nearby Git concept.","help":{"concept":"Turn an ordinary project folder into a Git repository on `main`, inspect the metadata Git created, and keep the author identity local to that repository.","hint_1":"Pay attention to whether the prompt describes an untracked path, a working-tree edit, staged work, or history.","hint_2":"Read spaces, punctuation, and status columns as meaningful when the question shows Git output."},"template":"git config --local user.name [blank1]","choices":["\"ZoeSkoul Learner\"","\"John Doe\"","\"Jane Smith\"","\"Git User\""]}}},"module-1-field-notes-repository":{"label":"Module Project: Start Volunteer Project History","summary":"Begin the two-file volunteer-project repository and record its first snapshot.","cards":{"sketch0":{"title":"Parallel Project: Volunteer Project"},"project":{"title":"Build the Volunteer Project Baseline"}},"projectSteps":{"try_git_repo_inspection":{"title":"Inspect the Volunteer Project Folder"},"try_git_config":{"title":"Initialize Volunteer Project"},"try_git_init":{"title":"Configure the Volunteer Project Identity"},"try_git_stage_files":{"title":"Stage the Volunteer Project Baseline"},"try_git_commit":{"title":"Commit the Volunteer Project Baseline"}},"moduleProject":{"steps":{"try_git_repo_inspection":{"title":"Inspect the Volunteer Project Folder","prompt":"The project opens inside `volunteer-project/`. Use `pwd` to confirm your current directory, then use `ls` to verify that the folder contains these two plain-text files:\n\n* `README.md`\n* `assignments.txt`\n\nDo not initialize a Git repository yet.","hint":"Verify the project root and its small two-file starting set.","help":{"concept":"`pwd` prints the current directory. `ls` lists visible files in that directory. These terminal commands inspect the ordinary folder before Git is initialized.","hint_1":"The terminal is already inside `volunteer-project/`.","hint_2":"The listing should contain only the two learner files."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"pwd\nls","instructions":"The parallel project opens inside `volunteer-project/`. Confirm the current directory and list its two plain-text files: `README.md` and `assignments.txt`. Do not initialize Git yet.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you confirm the current project directory?"},"1":{"message":"Did you list the two supplied text files?"}}}},"try_git_config":{"title":"Initialize the Volunteer Project","prompt":"The two-file folder is ready and still has no Git repository metadata. Using the command you learned in the previous lesson, initialize a new Git repository with `main` as the initial branch. Do not change either file.","hint":"Reapply the initialization command from the guided project.","help":{"concept":"`git init -b main` creates repository metadata in the current folder and selects `main` as the first branch. The files remain untracked until you stage them.","hint_1":"Do not create another directory.","hint_2":"No commit should exist yet."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git init -b main","instructions":"The two-file folder is ready and still has no repository metadata. Initialize it on `main` without changing either file.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you initialize the current volunteer project on `main`?"}}}},"try_git_init":{"title":"Configure the Volunteer Project Identity","prompt":"Now that you have initialized the local Git repository, configure the commit identity for this repository only. Set the name to `ZoeSkoul Learner` and the email address to `learner@zoeskoul.local`.\n\nDo not change the global Git configuration.","hint":"Use the same two repository-local settings as the guided project.","help":{"concept":"`git config --local user.name VALUE` and `git config --local user.email VALUE` prepare this independent repository to record commits without changing global Git settings.","hint_1":"Use both exact supplied values.","hint_2":"Keep both settings local."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git config --local user.name \"ZoeSkoul Learner\"\ngit config --local user.email \"learner@zoeskoul.local\"","instructions":"Store the supplied name `ZoeSkoul Learner` and email `learner@zoeskoul.local` in this repository only.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you store the supplied local author name?"},"1":{"message":"Did you store the supplied local author email?"}}}},"try_git_stage_files":{"title":"Prepare the Volunteer Baseline","prompt":"The repository has been initialized, and its local commit identity is configured. Now it is time to prepare the first snapshot.\n\nStage only `README.md` and `assignments.txt`. Then, before committing, use the command you learned in the previous lesson to inspect the statistics for the staged changes.","hint":"Prepare the complete two-file baseline and review it.","help":{"concept":"`git add file1 file2` stages both project files.","hint_1":"`git diff --staged --stat` confirms which files the first snapshot would contain without recording it.","hint_2":"The staged summary should contain exactly two files."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git add README.md assignments.txt\ngit diff --staged --stat","instructions":"Stage only `README.md` and `assignments.txt`, then inspect the staged statistics before committing.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage both supplied volunteer files?"},"1":{"message":"Did you inspect the staged file summary?"}}}},"try_git_commit":{"title":"Record and Verify the Volunteer Baseline","prompt":"Now record the prepared two-file snapshot with the commit message `Start volunteer project`.\n\nAfter the commit is created, use the commands you learned earlier to inspect the concise history and confirm that the short status shows no unfinished changes.","hint":"Commit once, then verify history and current state.","help":{"concept":"`git commit -m ...` records the staged files. ","hint_1":"`git log --oneline` verifies the history entry,","hint_2":"and `git status --short` verifies that no tracked work remains unfinished."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git commit -m \"Start volunteer project\"\ngit log --oneline\ngit status --short","instructions":"Record the prepared two-file snapshot with the message `Start volunteer project`. Then inspect concise history and confirm that short status has no unfinished entries.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\ngit -C volunteer-project add -A\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\ngit -C volunteer-project add -A\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nAssignments and meeting times.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the volunteer baseline with the requested message?"},"1":{"message":"Did you inspect the concise history?"},"2":{"message":"Did you verify that no unfinished file entries remain?"}}}}},"title":"Build the Volunteer Project Baseline","description":"This project starts with only README.md and assignments.txt. Reapply the Module 1 workflow in a different repository, then carry that exact history into later module projects."}},"module-1-volunteer-project-history":{"label":"Module Project: Start Volunteer Project History","summary":"Begin the two-file volunteer-project repository and record its first snapshot.","cards":{"sketch0":{"title":"Parallel Project: Volunteer Project"},"project":{"title":"Build the Volunteer Project Baseline"}},"projectSteps":{"try_git_repo_inspection":{"title":"Inspect the Volunteer Project Folder"},"try_git_config":{"title":"Initialize Volunteer Project"},"try_git_init":{"title":"Configure the Volunteer Project Identity"},"try_git_stage_files":{"title":"Stage the Volunteer Project Baseline"},"try_git_commit":{"title":"Commit the Volunteer Project Baseline"}},"moduleProject":{"steps":{"try_git_repo_inspection":{"title":"Inspect the Volunteer Project Folder","prompt":"The project opens inside `volunteer-project/`. Use `pwd` to confirm your current directory, then use `ls` to verify that the folder contains these two plain-text files:\n\n* `README.md`\n* `assignments.txt`\n\nDo not initialize a Git repository yet.","hint":"Verify the project root and its small two-file starting set.","help":{"concept":"`pwd` prints the current directory. `ls` lists visible files in that directory. These terminal commands inspect the ordinary folder before Git is initialized.","hint_1":"The terminal is already inside `volunteer-project/`.","hint_2":"The listing should contain only the two learner files."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"pwd\nls","instructions":"The parallel project opens inside `volunteer-project/`. Confirm the current directory and list its two plain-text files: `README.md` and `assignments.txt`. Do not initialize Git yet.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you confirm the current project directory?"},"1":{"message":"Did you list the two supplied text files?"}}}},"try_git_config":{"title":"Initialize the Volunteer Project","prompt":"The two-file folder is ready and still has no Git repository metadata. Using the command you learned in the previous lesson, initialize a new Git repository with `main` as the initial branch. Do not change either file.","hint":"Reapply the initialization command from the guided project.","help":{"concept":"`git init -b main` creates repository metadata in the current folder and selects `main` as the first branch. The files remain untracked until you stage them.","hint_1":"Do not create another directory.","hint_2":"No commit should exist yet."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git init -b main","instructions":"The two-file folder is ready and still has no repository metadata. Initialize it on `main` without changing either file.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you initialize the current volunteer project on `main`?"}}}},"try_git_init":{"title":"Configure the Volunteer Project Identity","prompt":"Now that you have initialized the local Git repository, configure the commit identity for this repository only. Set the name to `ZoeSkoul Learner` and the email address to `learner@zoeskoul.local`.\n\nDo not change the global Git configuration.","hint":"Use the same two repository-local settings as the guided project.","help":{"concept":"`git config --local user.name VALUE` and `git config --local user.email VALUE` prepare this independent repository to record commits without changing global Git settings.","hint_1":"Use both exact supplied values.","hint_2":"Keep both settings local."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git config --local user.name \"ZoeSkoul Learner\"\ngit config --local user.email \"learner@zoeskoul.local\"","instructions":"Store the supplied name `ZoeSkoul Learner` and email `learner@zoeskoul.local` in this repository only.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you store the supplied local author name?"},"1":{"message":"Did you store the supplied local author email?"}}}},"try_git_stage_files":{"title":"Prepare the Volunteer Baseline","prompt":"The repository has been initialized, and its local commit identity is configured. Now it is time to prepare the first snapshot.\n\nStage only `README.md` and `assignments.txt`. Then, before committing, use the command you learned in the previous lesson to inspect the statistics for the staged changes.","hint":"Prepare the complete two-file baseline and review it.","help":{"concept":"`git add file1 file2` stages both project files.","hint_1":"`git diff --staged --stat` confirms which files the first snapshot would contain without recording it.","hint_2":"The staged summary should contain exactly two files."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git add README.md assignments.txt\ngit diff --staged --stat","instructions":"Stage only `README.md` and `assignments.txt`, then inspect the staged statistics before committing.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage both supplied volunteer files?"},"1":{"message":"Did you inspect the staged file summary?"}}}},"try_git_commit":{"title":"Record and Verify the Volunteer Baseline","prompt":"Now record the prepared two-file snapshot with the commit message `Start volunteer project`.\n\nAfter the commit is created, use the commands you learned earlier to inspect the concise history and confirm that the short status shows no unfinished changes.","hint":"Commit once, then verify history and current state.","help":{"concept":"`git commit -m ...` records the staged files. ","hint_1":"`git log --oneline` verifies the history entry,","hint_2":"and `git status --short` verifies that no tracked work remains unfinished."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git commit -m \"Start volunteer project\"\ngit log --oneline\ngit status --short","instructions":"Record the prepared two-file snapshot with the message `Start volunteer project`. Then inspect concise history and confirm that short status has no unfinished entries.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\ngit -C volunteer-project add -A\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- volunteer-project\nmkdir -p -- volunteer-project\ngit -C volunteer-project init -q -b main\ngit -C volunteer-project config --local user.name 'ZoeSkoul Learner'\ngit -C volunteer-project config --local user.email learner@zoeskoul.local\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\ngit -C volunteer-project add -A\nfind volunteer-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- volunteer-project\nprintf %s '# Volunteer Project\n\nVolunteer coordination notes.\n' > volunteer-project/README.md\nmkdir -p -- volunteer-project\nprintf %s 'Volunteer assignments\n\nWelcome table: Sam\nTraining desk: unassigned\n' > volunteer-project/assignments.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the volunteer baseline with the requested message?"},"1":{"message":"Did you inspect the concise history?"},"2":{"message":"Did you verify that no unfinished file entries remain?"}}}}},"title":"Build the Volunteer Project Baseline","description":"This project starts with only README.md and assignments.txt. Reapply the Module 1 workflow in a different repository, then carry that exact history into later module projects."}},"read-tracked-and-untracked-state":{"label":"Read the Community Project State","summary":"Inspect the two untracked files, stage them, and review the proposed snapshot.","cards":{"sketch0":{"title":"Status Compares Three Layers"},"sketch1":{"title":"Short Status Is a Compact Map"},"sketch2":{"title":"Read the Staged Summary"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_read_tracked_and_untracked_state_sketch0":{"title":"Read the Initial Repository State","prompt":"Ask Git for the full repository report. Use it to confirm that the branch is `main`, no commits exist yet, and `README.md` plus `schedule.txt` are untracked. Do not change repository state.","hint":"Use Git’s full status report as a read-only inspection.","help":{"concept":"`git status` describes the current branch and separates staged, unstaged, and untracked work. Running it does not change any file or repository layer.","hint_1":"Look for the `No commits yet` message and the two untracked file names.","hint_2":"Do not stage either file in this step."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git status","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"instructions":"Ask Git for the full repository report. Use it to confirm that the branch is `main`, no commits exist yet, and `README.md` plus `schedule.txt` are untracked. Do not change repository state.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you ask Git for the full repository report?"}}}},"try_read_tracked_and_untracked_state_sketch1":{"title":"Stage the Two Project Files","prompt":"Prepare the first proposed snapshot by staging only `README.md` and `schedule.txt`. Then inspect compact status and confirm that both paths appear in the staging-area column.","hint":"Name the two project files explicitly, then read compact status.","help":{"concept":"`git add README.md schedule.txt` copies the current versions of those two files into the staging area. `git status --short` compresses repository state into two columns; an `A` in the left column means the file is staged as an addition.","hint_1":"There are only two learner files in this module.","hint_2":"Staging prepares a proposal; it does not create a commit."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git add README.md schedule.txt\ngit status --short","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"instructions":"Prepare the first proposed snapshot by staging only `README.md` and `schedule.txt`. Then inspect compact status and confirm that both paths appear in the staging-area column.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage both `README.md` and `schedule.txt`?"},"1":{"message":"Did you inspect the compact staged state?"}}}},"try_read_tracked_and_untracked_state_sketch2":{"title":"Review the Staged File Summary","prompt":"Both files are staged, but no commit has been created yet. Use the command you learned earlier to inspect the staged summary and confirm that the proposed snapshot contains exactly two files.\n\nDo not create the commit yet.","hint":"Ask Git for a statistics-only view of the staging area.","help":{"concept":"`git diff --staged --stat` summarizes the files and line counts currently in the staging area. `--staged` reads the proposed snapshot, and `--stat` keeps the output compact. The command does not commit anything.","hint_1":"The summary should name `README.md` and `schedule.txt`.","hint_2":"Leave both files staged for the next lesson."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git diff --staged --stat","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\ngit -C community-project add -A\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\ngit -C community-project add -A\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"instructions":"The two files are staged and no commit exists yet. Inspect the staged summary to verify that the proposed snapshot contains exactly two files without recording it.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the staged two-file summary?"}}}}},"practice":{"single-choice-2":{"title":"Understanding git status --short","prompt":"What does the `??` symbol indicate in the output of `git status --short`?","hint":"In short status, two question marks appear beside a file Git has not started tracking.","help":{"concept":"Read full and short status reports to tell untracked files, unstaged edits, staged work, and clean state apart.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"A modified file","b":"A deleted file","c":"An untracked file","d":"A staged file"}},"multi-choice-1":{"title":"Read the Two Columns","prompt":"Which statements about short status are correct? Select all that apply.","hint":"Judge each option independently; choose only the statements that stay true in this exact repository state.","help":{"concept":"Read full and short status reports to tell untracked files, unstaged edits, staged work, and clean state apart.","hint_1":"A partly true option is still wrong if it adds an effect Git does not guarantee.","hint_2":"Use the layer named in the prompt—working tree, staging area, or history—to test each choice."},"options":{"a":"The left column describes staged changes.","b":"The right column describes working-tree changes.","c":"`??` marks an untracked path.","d":"Every listed path has already been committed."}},"fill-blank-choice-1":{"title":"Unstaged Modification Column","prompt":"In short status, an unstaged tracked-file edit uses the letter `[blank1]` in the right column.","hint":"Choose the term or symbol that matches the exact state described, not a nearby Git concept.","help":{"concept":"Read full and short status reports to tell untracked files, unstaged edits, staged work, and clean state apart.","hint_1":"Pay attention to whether the prompt describes an untracked path, a working-tree edit, staged work, or history.","hint_2":"Read spaces, punctuation, and status columns as meaningful when the question shows Git output."},"template":"An unstaged tracked-file edit uses `[blank1]` in the right column.","choices":["M","A","D","??"]},"fill-blank-choice-2":{"title":"Untracked File Marker","prompt":"In short status, a file Git has never tracked begins with `[blank1]`.","hint":"Choose the term or symbol that matches the exact state described, not a nearby Git concept.","help":{"concept":"Read full and short status reports to tell untracked files, unstaged edits, staged work, and clean state apart.","hint_1":"Pay attention to whether the prompt describes an untracked path, a working-tree edit, staged work, or history.","hint_2":"Read spaces, punctuation, and status columns as meaningful when the question shows Git output."},"template":"A file Git has never tracked begins with `[blank1]`.","choices":["??","M ","A ","D "]}}},"why-version-control-matters":{"label":"Why Version Control Matters","summary":"Meet Git, review the small terminal skills you need, and see how three projects build the same inspect-change-verify habit.","cards":{"sketch0":{"title":"Before You Begin"},"sketch1":{"title":"Three Small Projects, One Learning Pattern"}}},"working-tree-staging-and-history":{"label":"Record the First Community Project Snapshot","summary":"Commit the staged two-file baseline and verify its history and clean state.","cards":{"sketch0":{"title":"The Proposal Carries Forward"},"sketch1":{"title":"A Commit Records the Proposal"},"sketch2":{"title":"Verify History and Current State Separately"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_working_tree_staging_and_history_sketch0":{"title":"Record the First Community Snapshot","prompt":"The two project files are already staged. Record that proposal with the commit message `Start community project`. Do not restage or edit anything.","hint":"Commit the prepared staging area with the exact message.","help":{"concept":"`git commit -m \"Start community project\"` records the current staging area as one local history entry. `-m` supplies the commit message directly. Only staged content enters the commit.","hint_1":"Use the message exactly as written.","hint_2":"After the command, the repository should contain one commit."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git commit -m \"Start community project\"","instructions":"The two project files are already staged. Record that proposal with the commit message `Start community project`. Do not restage or edit anything.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\ngit -C community-project add -A\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- community-project\nmkdir -p -- community-project\ngit -C community-project init -q -b main\ngit -C community-project config --local user.name 'ZoeSkoul Learner'\ngit -C community-project config --local user.email learner@zoeskoul.local\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\ngit -C community-project add -A\nfind community-project -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf -- {} +\nmkdir -p -- community-project\nprintf %s '# Community Project\n\nShared community activities and updates.\n' > community-project/README.md\nmkdir -p -- community-project\nprintf %s 'Community events\n\nSaturday cleanup: 10:00 AM\n' > community-project/schedule.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the staged two-file snapshot with the requested message?"}}}},"try_working_tree_staging_and_history_sketch1":{"title":"Read the First History Entry","prompt":"Read the concise history and confirm that the newest entry is `Start community project`.","hint":"Use the one-line history view.","help":{"concept":"`git log --oneline` lists commits newest first, showing a short identifier and the commit message on one line. It reads history without changing it.","hint_1":"There should be exactly one history entry.","hint_2":"The short identifier can differ; the message is what matters here."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git log --oneline","instructions":"Read the concise history and confirm that the newest entry is `Start community project`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$28"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$29"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you read the concise commit history?"}}}},"try_working_tree_staging_and_history_sketch2":{"title":"Confirm a Clean Working State","prompt":"Inspect compact status after the first commit. A clean repository produces no file entries.","hint":"Read short status and look for an empty result.","help":{"concept":"`git status --short` prints one line per unfinished path. No output means the working tree and staging area match the current commit.","hint_1":"Do not create or edit a file.","hint_2":"The repository should remain at one commit."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git status --short","instructions":"Inspect compact status after the first commit. A clean repository produces no file entries.","starterFiles":{"zoeskoul_setup_sh":{"content":"$2a"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$2b"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you verify that no unfinished file entries remain?"}}}}},"practice":{"single-choice-1":{"title":"Identify the Working Tree","prompt":"What is the working tree in Git?","hint":"Choose the layer that contains the project files you can open and edit right now.","help":{"concept":"Follow one edit from the working tree to the staging area and into a named commit, checking each boundary along the way.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"The project files and folders you can currently edit","b":"The proposed snapshot prepared for the next commit","c":"The sequence of recorded commits","d":"The list of patterns Git should ignore"}},"single-choice-2":{"title":"Purpose of the Staging Area","prompt":"What is the purpose of the staging area in Git?","hint":"Choose the layer where selected changes wait before they become a commit.","help":{"concept":"Follow one edit from the working tree to the staging area and into a named commit, checking each boundary along the way.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"To prepare selected changes for the next commit","b":"To store the complete commit history","c":"To display only unstaged line changes","d":"To initialize an ordinary folder"}},"multi-choice-1":{"title":"What a Commit Records","prompt":"Which facts about a commit are correct? Select all that apply.","hint":"Judge each option independently; choose only the statements that stay true in this exact repository state.","help":{"concept":"Follow one edit from the working tree to the staging area and into a named commit, checking each boundary along the way.","hint_1":"A partly true option is still wrong if it adds an effect Git does not guarantee.","hint_2":"Use the layer named in the prompt—working tree, staging area, or history—to test each choice."},"options":{"a":"It records the staged snapshot.","b":"It includes a message and author identity.","c":"It automatically includes every unstaged edit.","d":"It becomes part of repository history."}},"drag-reorder-1":{"title":"Order of Git Workflow","prompt":"Arrange the steps of the Git workflow in the correct order.","hint":"Start with the state that must exist before the next action can make sense.","help":{"concept":"Follow one edit from the working tree to the staging area and into a named commit, checking each boundary along the way.","hint_1":"Track how the project moves from working files to a proposed snapshot and then to history.","hint_2":"Read the ordered steps as one continuous repository story."},"tokens":{"t1":"Edit files in the working tree","t2":"Stage changes in the staging area","t3":"Commit changes to the commit history"}}}}},"git-foundations-module-2-meaningful-history":{"inspect-unstaged-changes-with-diff":{"label":"Add and Inspect Exact Project Changes","summary":"Add one third file, then inspect two supplied text edits without staging them.","cards":{"sketch0":{"title":"Diff Shows Exact Text Changes"},"sketch2":{"title":"Name the File When Focus Matters"},"sketch3":{"title":"Inspect Before You Stage"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_inspect_unstaged_changes_with_diff_sketch0":{"title":"Create the Third Project File","prompt":"The community project continues with the two tracked files from Module 1: `README.md` and `schedule.txt`. The community organizers now need a contact list, but `contacts.txt` does not exist yet.\n\nCreate `community-project/contacts.txt`. Starting on line 1, enter exactly:\n\n```text\nCommunity contacts\n\nHelp desk: 555-0100\n```\nThen use the terminal to:\n\n1. Inspect the short status and confirm that Git shows `?? contacts.txt`.\n2. Stage only `contacts.txt`.\n3. Create a focused commit with the exact message `Add community contacts`.\n\nWhen you finish, the repository should contain three tracked files and two commits. Do not change `README.md` or `schedule.txt`.","hint":"Create and save the exact three-line file first. Then inspect it as untracked, stage only that file, and commit it with the supplied message.","help":{"concept":"An untracked file is not part of history until it is staged and committed. `git status --short` identifies it with `??`; `git add contacts.txt` stages it; `git commit -m \"Add community contacts\"` records it as the repository’s third file.","hint_1":"Do not change `README.md` or `schedule.txt`.","hint_2":"The new commit should add only `contacts.txt`."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git status --short\ngit add contacts.txt\ngit commit -m \"Add community contacts\"","starterFiles":{"zoeskoul_setup_sh":{"content":"$2c"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$2d"}},"instructions":"`community-project/` should begin this lesson with only `README.md` and `schedule.txt`; `contacts.txt` should not exist yet. Create `community-project/contacts.txt`. Starting on line 1, enter exactly these three lines: `Community contacts`, a blank line, and `Help desk: 555-0100`. Save the file.\n\nThen use the terminal to inspect short status, stage only `contacts.txt`, and record it with the exact commit message `Add community contacts`.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the new file before staging it?"},"1":{"message":"Did you stage only `contacts.txt`?"},"2":{"message":"Did you record the contact list as its own commit?"}}}},"try_inspect_unstaged_changes_with_diff_sketch2":{"title":"Change and Inspect the Cleanup Time","prompt":"The cleanup coordinator moved Saturday’s start time earlier so volunteers can finish before an afternoon event. Open `community-project/schedule.txt` and find this line:\n\n`Saturday cleanup: 10:00 AM`\n\nReplace it with:\n\n`Saturday cleanup: 9:30 AM`\n\nSave the file. Then use the command you learned earlier to inspect only the unstaged changes in `schedule.txt`.\n\nDo not stage the file yet.\n","hint":"Make the exact one-line edit, then compare the working copy with the staged version.","help":{"concept":"`git diff -- schedule.txt` shows unstaged line changes for that file. A removed line begins with `-` and an added line begins with `+`. The command is read-only.","hint_1":"Change only the cleanup time.","hint_2":"The diff should show one removed line and one added line."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git diff -- schedule.txt","starterFiles":{"zoeskoul_setup_sh":{"content":"$2e"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$2f"}},"instructions":"Open `community-project/schedule.txt`. Find `Saturday cleanup: 10:00 AM` and replace it with `Saturday cleanup: 9:30 AM`. Save the file. Then inspect only that unstaged change. Do not stage it yet.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the unstaged schedule change?"}}}},"try_inspect_unstaged_changes_with_diff_sketch3":{"title":"Change and Inspect the Help Desk Number","prompt":"The help desk has a new phone number, so the project contact list must be corrected. Open `community-project/contacts.txt` and find this line:\n\n`Help desk: 555-0100`\n\nReplace it with:\n\n`Help desk: 555-0130`. Then use the command you learned earlier to inspect only the unstaged changes in `contacts.txt`.\n\nLeave the changes in both `schedule.txt` and `contacts.txt` unstaged.\n","hint":"Make the exact contact edit and narrow the diff to that path.","help":{"concept":"`git diff -- contacts.txt` limits the unstaged comparison to the contact file even though another file is also modified. Naming the path changes only the output, not repository state.","hint_1":"Do not stage either edit.","hint_2":"The schedule change must remain present for the next topic."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git diff -- contacts.txt","starterFiles":{"zoeskoul_setup_sh":{"content":"$30"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$31"}},"instructions":"Open `community-project/contacts.txt`. Find `Help desk: 555-0100` and replace it with `Help desk: 555-0130`. Save the file. Then inspect only the contact change. Leave both edits unstaged.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect only the contact-number change?"}}}}},"practice":{"single-choice-1":{"title":"Using git diff","prompt":"When should you use `git diff`?","hint":"Ordinary `git diff` is most useful while a working-tree edit is still unstaged.","help":{"concept":"Move from a file-level status report to a line-level review, and separate unrelated edits before they reach the staging area.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"After the change has already been committed","b":"Before staging a working-tree change","c":"When you want to list earlier commit subjects","d":"When you want to create repository metadata"}},"multi-choice-2":{"title":"Interpreting Diff Output","prompt":"Which symbol in `git diff` output indicates a line has been added?","hint":"Choose the one answer that describes this command or concept precisely.","help":{"concept":"Move from a file-level status report to a line-level review, and separate unrelated edits before they reach the staging area.","hint_1":"Remove choices that act on a different repository layer or promise behavior Git does not provide.","hint_2":"Prefer the exact definition used in this chapter over a nearby Git idea."},"options":{"a":"-","b":"+","c":"*","d":"/"}},"fill-blank-choice-1":{"title":"Symbol for Removed Lines","prompt":"In `git diff`, lines that have been removed are indicated by the symbol `[blank1]`.","hint":"Choose the term or symbol that matches the exact state described, not a nearby Git concept.","help":{"concept":"Move from a file-level status report to a line-level review, and separate unrelated edits before they reach the staging area.","hint_1":"Pay attention to whether the prompt describes an untracked path, a working-tree edit, staged work, or history.","hint_2":"Read spaces, punctuation, and status columns as meaningful when the question shows Git output."},"template":"In `git diff`, lines that have been removed are indicated by the symbol `[blank1]`.","choices":["-","+","*","/"]},"fill-blank-choice-2":{"title":"Purpose of git diff","prompt":"The primary purpose of `git diff` is to show changes in the [blank1] that are not yet staged.","hint":"Choose the term or symbol that matches the exact state described, not a nearby Git concept.","help":{"concept":"Move from a file-level status report to a line-level review, and separate unrelated edits before they reach the staging area.","hint_1":"Pay attention to whether the prompt describes an untracked path, a working-tree edit, staged work, or history.","hint_2":"Read spaces, punctuation, and status columns as meaningful when the question shows Git output."},"template":"The primary purpose of `git diff` is to show changes in the [blank1] that are not yet staged.","choices":["working tree","staging area","commit history","ignore file"]}}},"module-2-community-website-history":{"label":"Module Project: Build Volunteer Project History","summary":"Add one file and record two focused volunteer-project updates.","cards":{"sketch0":{"title":"Continue Volunteer Project"},"project":{"title":"Build Focused Volunteer Project History"}},"projectSteps":{"try_module_2_community_website_history_sketch0":{"title":"Edit the Signup Schedule Entry"},"try_module_2_community_website_history_sketch1":{"title":"Commit the Signup Schedule Entry"},"try_module_2_community_website_history_sketch2":{"title":"Edit the Help Desk Number"},"try_module_2_community_website_history_sketch3":{"title":"Stage and Review the Styles"},"try_module_2_community_website_history_sketch4":{"title":"Commit the Styles Separately"},"try_module_2_community_website_history_sketch5":{"title":"Audit the Volunteer Project History"}},"moduleProject":{"steps":{"try_module_2_community_website_history_sketch0":{"title":"Add the Meeting-Times File","prompt":"Continue `volunteer-project/` from its Module 1 snapshot. Create `meeting-times.txt` with exactly three lines: `Volunteer meeting times`, a blank line, and `Orientation: Saturday 10:00 AM`. Save it, stage it, and commit it with the message `Add volunteer meeting times`.","hint":"Add only the supplied third file and record it separately.","help":{"concept":"This step reuses the familiar new-file workflow: create the exact text, stage the path, and commit it. The repository grows from two files to three without introducing unrelated content.","hint_1":"Do not edit `README.md` or `assignments.txt`.","hint_2":"The new commit should add only `meeting-times.txt`."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git status --short\ngit add meeting-times.txt\ngit commit -m \"Add volunteer meeting times\"","instructions":"Continue `volunteer-project/` from its Module 1 snapshot. Create `meeting-times.txt` with exactly three lines: `Volunteer meeting times`, a blank line, and `Orientation: Saturday 10:00 AM`. Save it, stage it, and commit it with the message `Add volunteer meeting times`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$32"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$33"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the new meeting-times file?"},"1":{"message":"Did you stage only the new meeting-times file?"},"2":{"message":"Did you record the third file as its own commit?"}}}},"try_module_2_community_website_history_sketch1":{"title":"Inspect the Assignment Change","prompt":"Open `volunteer-project/assignments.txt`. Replace `Training desk: unassigned` with `Training desk: Riley`. Save the file, then inspect its unstaged diff.","hint":"Make the exact one-line change and review it before staging.","help":{"concept":"`git diff -- assignments.txt` shows the unstaged assignment change and leaves repository state untouched.","hint_1":"Do not change the welcome-table assignment.","hint_2":"Leave the edit unstaged for the next step."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git diff -- assignments.txt","instructions":"Open `volunteer-project/assignments.txt`. Replace `Training desk: unassigned` with `Training desk: Riley`. Save the file, then inspect its unstaged diff.","starterFiles":{"zoeskoul_setup_sh":{"content":"$34"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$35"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the assignment change before staging it?"}}}},"try_module_2_community_website_history_sketch2":{"title":"Stage and Review the Assignment Change","prompt":"Stage only `assignments.txt`, then inspect its staged diff.","hint":"Prepare and review one focused purpose.","help":{"concept":"`git add assignments.txt` moves the edit into the staging area. `git diff --staged -- assignments.txt` verifies exactly what the next commit would record.","hint_1":"No other file should be staged.","hint_2":"Do not commit yet."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git add assignments.txt\ngit diff --staged -- assignments.txt","instructions":"Stage only `assignments.txt`, then inspect its staged diff.","starterFiles":{"zoeskoul_setup_sh":{"content":"$36"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$37"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage only the assignment change?"},"1":{"message":"Did you review the staged assignment change?"}}}},"try_module_2_community_website_history_sketch3":{"title":"Commit the Assignment Change","prompt":"Record the staged assignment update with the message `Update volunteer assignments`.","hint":"Commit the prepared one-file snapshot.","help":{"concept":"`git commit -m \"Update volunteer assignments\"` records the staged assignment change and leaves the repository ready for the meeting-time update.","hint_1":"Use the exact message.","hint_2":"The repository should be clean immediately afterward."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git commit -m \"Update volunteer assignments\"","instructions":"Record the staged assignment update with the message `Update volunteer assignments`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$38"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$39"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the assignment update as its own commit?"}}}},"try_module_2_community_website_history_sketch4":{"title":"Move the Orientation Earlier","prompt":"Open `volunteer-project/meeting-times.txt`. Replace `Orientation: Saturday 10:00 AM` with `Orientation: Saturday 9:30 AM`. Save the file. Inspect the unstaged diff, stage the file, review the staged diff, and commit it with the message `Update volunteer meeting time`.","hint":"Follow the complete inspect, stage, review, commit workflow for the exact time change.","help":{"concept":"`git diff` reviews the working-tree edit, `git add` prepares it, `git diff --staged` reviews the proposal, and `git commit` records the focused snapshot.","hint_1":"Do not edit another file.","hint_2":"The new commit should affect only `meeting-times.txt`."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git diff -- meeting-times.txt\ngit add meeting-times.txt\ngit diff --staged -- meeting-times.txt\ngit commit -m \"Update volunteer meeting time\"","instructions":"Open `volunteer-project/meeting-times.txt`. Replace `Orientation: Saturday 10:00 AM` with `Orientation: Saturday 9:30 AM`. Save the file. Inspect the unstaged diff, stage the file, review the staged diff, and commit it with the message `Update volunteer meeting time`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$3a"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$3b"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the meeting-time change?"},"1":{"message":"Did you stage the meeting-time change?"},"2":{"message":"Did you review the staged meeting-time change?"},"3":{"message":"Did you record the meeting-time update separately?"}}}},"try_module_2_community_website_history_sketch5":{"title":"Audit the Volunteer Project History","prompt":"Inspect the concise history, the newest commit summary, and final short status. Confirm that the repository contains four focused commits and no unfinished tracked work.","hint":"Verify timeline, latest snapshot, and current state.","help":{"concept":"`git log --oneline` audits the sequence, `git show --stat --oneline HEAD` audits the newest snapshot, and `git status --short` verifies the handoff is clean.","hint_1":"The newest message should be `Update volunteer meeting time`.","hint_2":"Short status should produce no file entries."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git log --oneline\ngit show --stat --oneline HEAD\ngit status --short","instructions":"Inspect the concise history, the newest commit summary, and final short status. Confirm that the repository contains four focused commits and no unfinished tracked work.","starterFiles":{"zoeskoul_setup_sh":{"content":"$3c"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$3d"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the volunteer history?"},"1":{"message":"Did you inspect the newest snapshot summary?"},"2":{"message":"Did you verify a clean current state?"}}}}},"description":"Continue the same volunteer-project repository. Add one third file, then create two focused text changes without introducing unrelated files.","title":"Build Focused Volunteer Project History"}},"module-2-volunteer-project-history":{"label":"Module Project: Build Volunteer Project History","summary":"Add one file and record two focused volunteer-project updates.","cards":{"sketch0":{"title":"Continue Volunteer Project"},"project":{"title":"Build Focused Volunteer Project History"}},"projectSteps":{"try_module_2_community_website_history_sketch0":{"title":"Edit the Signup Schedule Entry"},"try_module_2_community_website_history_sketch1":{"title":"Commit the Signup Schedule Entry"},"try_module_2_community_website_history_sketch2":{"title":"Edit the Help Desk Number"},"try_module_2_community_website_history_sketch3":{"title":"Stage and Review the Styles"},"try_module_2_community_website_history_sketch4":{"title":"Commit the Styles Separately"},"try_module_2_community_website_history_sketch5":{"title":"Audit the Volunteer Project History"}},"moduleProject":{"steps":{"try_module_2_community_website_history_sketch0":{"title":"Add the Meeting-Times File","prompt":"Continue `volunteer-project/` from its Module 1 snapshot. Create `meeting-times.txt` with exactly three lines: `Volunteer meeting times`, a blank line, and `Orientation: Saturday 10:00 AM`. Save it, stage it, and commit it with the message `Add volunteer meeting times`.","hint":"Add only the supplied third file and record it separately.","help":{"concept":"This step reuses the familiar new-file workflow: create the exact text, stage the path, and commit it. The repository grows from two files to three without introducing unrelated content.","hint_1":"Do not edit `README.md` or `assignments.txt`.","hint_2":"The new commit should add only `meeting-times.txt`."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git status --short\ngit add meeting-times.txt\ngit commit -m \"Add volunteer meeting times\"","instructions":"Continue `volunteer-project/` from its Module 1 snapshot. Create `meeting-times.txt` with exactly three lines: `Volunteer meeting times`, a blank line, and `Orientation: Saturday 10:00 AM`. Save it, stage it, and commit it with the message `Add volunteer meeting times`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$3e"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$3f"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the new meeting-times file?"},"1":{"message":"Did you stage only the new meeting-times file?"},"2":{"message":"Did you record the third file as its own commit?"}}}},"try_module_2_community_website_history_sketch1":{"title":"Inspect the Assignment Change","prompt":"Riley has agreed to manage the training desk. Open `volunteer-project/assignments.txt`. Replace `Training desk: unassigned` with `Training desk: Riley`. Save the file, then inspect its unstaged diff.","hint":"Make the exact one-line change and review it before staging.","help":{"concept":"`git diff -- assignments.txt` shows the unstaged assignment change and leaves repository state untouched.","hint_1":"Do not change the welcome-table assignment.","hint_2":"Leave the edit unstaged for the next step."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git diff -- assignments.txt","instructions":"Riley has agreed to manage the training desk. Open `volunteer-project/assignments.txt`. Replace `Training desk: unassigned` with `Training desk: Riley`. Save the file, then inspect its unstaged diff.","starterFiles":{"zoeskoul_setup_sh":{"content":"$40"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$41"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the assignment change before staging it?"}}}},"try_module_2_community_website_history_sketch2":{"title":"Stage and Review the Assignment Change","prompt":"Stage only `assignments.txt`, then inspect its staged diff.","hint":"Prepare and review one focused purpose.","help":{"concept":"`git add assignments.txt` moves the edit into the staging area. `git diff --staged -- assignments.txt` verifies exactly what the next commit would record.","hint_1":"No other file should be staged.","hint_2":"Do not commit yet."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git add assignments.txt\ngit diff --staged -- assignments.txt","instructions":"Stage only `assignments.txt`, then inspect its staged diff.","starterFiles":{"zoeskoul_setup_sh":{"content":"$42"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$43"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage only the assignment change?"},"1":{"message":"Did you review the staged assignment change?"}}}},"try_module_2_community_website_history_sketch3":{"title":"Commit the Assignment Change","prompt":"Record the staged assignment update with the message `Update volunteer assignments`.","hint":"Commit the prepared one-file snapshot.","help":{"concept":"`git commit -m \"Update volunteer assignments\"` records the staged assignment change and leaves the repository ready for the meeting-time update.","hint_1":"Use the exact message.","hint_2":"The repository should be clean immediately afterward."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git commit -m \"Update volunteer assignments\"","instructions":"Record the staged assignment update with the message `Update volunteer assignments`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$44"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$45"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the assignment update as its own commit?"}}}},"try_module_2_community_website_history_sketch4":{"title":"Move the Orientation Earlier","prompt":"The orientation coordinator moved the session earlier so setup can finish before visitors arrive. Open `volunteer-project/meeting-times.txt`. Replace `Orientation: Saturday 10:00 AM` with `Orientation: Saturday 9:30 AM`. Save the file. Inspect the unstaged diff, stage the file, review the staged diff, and commit it with the message `Update volunteer meeting time`.","hint":"Follow the complete inspect, stage, review, commit workflow for the exact time change.","help":{"concept":"`git diff` reviews the working-tree edit, `git add` prepares it, `git diff --staged` reviews the proposal, and `git commit` records the focused snapshot.","hint_1":"Do not edit another file.","hint_2":"The new commit should affect only `meeting-times.txt`."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git diff -- meeting-times.txt\ngit add meeting-times.txt\ngit diff --staged -- meeting-times.txt\ngit commit -m \"Update volunteer meeting time\"","instructions":"The orientation coordinator moved the session earlier so setup can finish before visitors arrive. Open `volunteer-project/meeting-times.txt`. Replace `Orientation: Saturday 10:00 AM` with `Orientation: Saturday 9:30 AM`. Save the file. Inspect the unstaged diff, stage the file, review the staged diff, and commit it with the message `Update volunteer meeting time`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$46"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$47"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the meeting-time change?"},"1":{"message":"Did you stage the meeting-time change?"},"2":{"message":"Did you review the staged meeting-time change?"},"3":{"message":"Did you record the meeting-time update separately?"}}}},"try_module_2_community_website_history_sketch5":{"title":"Audit the Volunteer Project History","prompt":"Inspect the concise history, the newest commit summary, and final short status. Confirm that the repository contains four focused commits and no unfinished tracked work.","hint":"Verify timeline, latest snapshot, and current state.","help":{"concept":"`git log --oneline` audits the sequence, `git show --stat --oneline HEAD` audits the newest snapshot, and `git status --short` verifies the handoff is clean.","hint_1":"The newest message should be `Update volunteer meeting time`.","hint_2":"Short status should produce no file entries."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git log --oneline\ngit show --stat --oneline HEAD\ngit status --short","instructions":"Inspect the concise history, the newest commit summary, and final short status. Confirm that the repository contains four focused commits and no unfinished tracked work.","starterFiles":{"zoeskoul_setup_sh":{"content":"$48"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$49"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the volunteer history?"},"1":{"message":"Did you inspect the newest snapshot summary?"},"2":{"message":"Did you verify a clean current state?"}}}}},"description":"Continue the same volunteer-project repository. Add one third file, then create two focused text changes without introducing unrelated files.","title":"Build Focused Volunteer Project History"}},"read-history-with-log-and-show":{"label":"Read the History You Built","summary":"Inspect the community-project history and committed file content without changing state.","cards":{"sketch0":{"title":"Read the Project Timeline"},"sketch1":{"title":"HEAD Names the Current Snapshot"},"sketch2":{"title":"Show Can Read Committed Content"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_read_history_with_log_and_show_sketch0":{"title":"Read the Four-Commit Timeline","prompt":"Read the commit messages from top to bottom and confirm that they appear in this order:\n\n1. `Update community contacts`\n2. `Update community schedule`\n3. `Add community contacts`\n4. `Start community project`\n\nTogether, these messages tell the story of how the project developed without requiring you to open each file.\n","hint":"Use the one-line history view.","help":{"concept":"`git log --oneline` lists commits newest first. It lets you audit the sequence of focused snapshots without changing repository state.","hint_1":"There should be four entries.","hint_2":"Check the messages rather than memorizing commit identifiers."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git log --oneline","instructions":"Read the concise history. Confirm that the newest entries are the contact update, the schedule update, the added contact file, and the original project snapshot.","starterFiles":{"zoeskoul_setup_sh":{"content":"$4a"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$4b"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you read the four-entry timeline?"}}}},"try_read_history_with_log_and_show_sketch1":{"title":"Inspect the Latest Snapshot Summary","prompt":"Use `git show --stat --oneline HEAD` to inspect that commit. The output combines its commit message with a compact summary of the file changed in the snapshot.\n\nConfirm that the newest commit is `Update community contacts` and that its statistics include only `contacts.txt`.","hint":"Ask Git to show `HEAD` with a one-line subject and file statistics.","help":{"concept":"`HEAD` names the current commit. `git show --stat --oneline HEAD` displays its subject plus a compact summary of the files changed in that snapshot.","hint_1":"The latest commit should concern `contacts.txt`.","hint_2":"This inspection must not change status."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git show --stat --oneline HEAD","instructions":"Inspect the newest commit and its compact file statistics.","starterFiles":{"zoeskoul_setup_sh":{"content":"$4c"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$4d"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the latest commit summary?"}}}},"try_read_history_with_log_and_show_sketch2":{"title":"Read a File from the Latest Snapshot","prompt":"Read the committed version of `contacts.txt` directly from `HEAD` without opening or changing the working file.","hint":"Use Git’s `commit:path` form.","help":{"concept":"`git show HEAD:contacts.txt` prints that file exactly as stored in the current commit. It reads history and leaves the working tree untouched.","hint_1":"The output should contain `Help desk: 555-0130`.","hint_2":"Do not redirect the output into a file."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git show HEAD:contacts.txt","instructions":"Read the committed version of `contacts.txt` directly from `HEAD` without opening or changing the working file.","starterFiles":{"zoeskoul_setup_sh":{"content":"$4e"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$4f"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you read the committed contact file from `HEAD`?"}}}}},"practice":{"single-choice-1":{"title":"HEAD in Git","prompt":"What does `HEAD` identify in this course?","hint":"`HEAD` points to the commit currently checked out, not to the staging area or the first commit.","help":{"concept":"Scan the repository timeline, open one checkpoint, understand `HEAD`, and move between overview and detail.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"The first commit ever recorded","b":"The staging area","c":"The currently checked-out commit","d":"The list of ignored paths"}},"multi-choice-1":{"title":"Understanding git log --oneline","prompt":"What information does `git log --oneline` provide?","hint":"Choose the one answer that describes this command or concept precisely.","help":{"concept":"Scan the repository timeline, open one checkpoint, understand `HEAD`, and move between overview and detail.","hint_1":"Remove choices that act on a different repository layer or promise behavior Git does not provide.","hint_2":"Prefer the exact definition used in this chapter over a nearby Git idea."},"options":{"a":"A full line-by-line diff for every commit","b":"A compact one-line summary of each commit","c":"Only the files currently in the staging area","d":"Only the untracked files in the working tree"}},"multi-choice-2":{"title":"Purpose of git show","prompt":"What is the primary purpose of the `git show` command?","hint":"Choose the one answer that describes this command or concept precisely.","help":{"concept":"Scan the repository timeline, open one checkpoint, understand `HEAD`, and move between overview and detail.","hint_1":"Remove choices that act on a different repository layer or promise behavior Git does not provide.","hint_2":"Prefer the exact definition used in this chapter over a nearby Git idea."},"options":{"a":"To list every commit as one short line","b":"To display the details of a selected commit","c":"To initialize an ordinary project folder","d":"To stage every current file"}},"drag-reorder-1":{"title":"Order of Git Commands","prompt":"Arrange the following Git commands in the order you would use them to inspect a commit's history and details.","hint":"Start with the state that must exist before the next action can make sense.","help":{"concept":"Scan the repository timeline, open one checkpoint, understand `HEAD`, and move between overview and detail.","hint_1":"Track how the project moves from working files to a proposed snapshot and then to history.","hint_2":"Read the ordered steps as one continuous repository story."},"tokens":{"t1":"git log --oneline","t2":"git show HEAD"}}}},"stage-intentionally":{"label":"Stage One Purpose at a Time","summary":"Separate two supplied community-project purposes into focused snapshots.","cards":{"sketch0":{"title":"One Project Can Hold Several Purposes"},"sketch1":{"title":"Stage the First Purpose by Name"},"sketch2":{"title":"Review the Staged Snapshot"},"sketch3":{"title":"Commit, Then Continue"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_stage_intentionally_sketch0":{"title":"Stage Only the Schedule Purpose","prompt":"A focused commit should contain one clear purpose. Use `git add schedule.txt` to stage only the schedule update. The contact change must remain unstaged in the working tree.\n\nAfter staging, the proposed snapshot should contain only the change to `schedule.txt`. Do not commit it yet.","hint":"Name the schedule path explicitly.","help":{"concept":"`git add schedule.txt` copies only the current schedule into the staging area. The contact edit stays unstaged, allowing the two purposes to become separate commits.","hint_1":"Do not use `git add .`.","hint_2":"After staging, short status would show one staged edit and one unstaged edit."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git add schedule.txt","starterFiles":{"zoeskoul_setup_sh":{"content":"$50"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$51"}},"instructions":"Two unrelated edits are present: the cleanup time in `schedule.txt` and the help-desk number in `contacts.txt`. Stage only `schedule.txt` so the first proposed snapshot contains one purpose.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage only the schedule change?"}}}},"try_stage_intentionally_sketch1":{"title":"Review the Proposed Schedule Snapshot","prompt":"Inspect only the staged change in `schedule.txt` before committing. The unstaged edit in `contacts.txt` must remain outside this comparison.\n\nDo not create the commit yet.\n","hint":"Read the staging-area diff for `schedule.txt`.","help":{"concept":"`git diff --staged -- schedule.txt` compares the staged schedule with the current commit. `--staged` is essential here because ordinary `git diff` reads unstaged work instead.","hint_1":"The output should show only the cleanup-time change.","hint_2":"Do not commit yet."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git diff --staged -- schedule.txt","starterFiles":{"zoeskoul_setup_sh":{"content":"$52"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$53"}},"instructions":"Inspect the staged schedule change before committing it. The unstaged contact edit must remain outside this comparison.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you review the staged schedule snapshot?"}}}},"try_stage_intentionally_sketch2":{"title":"Commit the Schedule Separately","prompt":"Now record the staged schedule update with the exact commit message `Update community schedule`.\n\nBecause only `schedule.txt` is staged, the commit will not include the unrelated change in `contacts.txt`.\n\nAfter committing, inspect the short status. Confirm that only the unstaged contact edit remains unfinished, proving that Git committed only the prepared schedule change.\n","hint":"Commit the current staging area, then inspect what remains.","help":{"concept":"`git commit -m \"Update community schedule\"` records only the staged schedule. `git status --short` then reveals the still-unstaged contact edit, proving the commit boundary stayed focused.","hint_1":"Do not stage `contacts.txt` before this commit.","hint_2":"The repository should gain one commit and retain one unstaged edit."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git commit -m \"Update community schedule\"\ngit status --short","starterFiles":{"zoeskoul_setup_sh":{"content":"$54"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$55"}},"instructions":"Record the staged schedule change with the message `Update community schedule`. Then inspect short status and confirm that only the contact edit remains unfinished.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the schedule as its own commit?"},"1":{"message":"Did you verify that the contact edit remains unstaged?"}}}},"try_stage_intentionally_sketch3":{"title":"Record the Contact Change Separately","prompt":"Stage only `contacts.txt`, inspect its staged change, and then create a commit with the exact message `Update community contacts`.\n\nWhen you finish, the contact update should be recorded in its own commit.\n","hint":"Prepare, inspect, and commit the remaining single-purpose change.","help":{"concept":"`git add contacts.txt` stages the remaining edit. `git diff --staged -- contacts.txt` reviews the proposal, and the commit records it as a separate history entry.","hint_1":"The staged diff should contain only the phone-number update.","hint_2":"The final repository state should be clean."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git add contacts.txt\ngit diff --staged -- contacts.txt\ngit commit -m \"Update community contacts\"","starterFiles":{"zoeskoul_setup_sh":{"content":"$56"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$57"}},"instructions":"Stage `contacts.txt`, review its staged diff, and record it with the message `Update community contacts`.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the remaining contact change?"},"1":{"message":"Did you review the staged contact change?"},"2":{"message":"Did you record the contact update separately?"}}}}},"practice":{"single-choice-1":{"title":"Choose a Focused Snapshot","prompt":"Two unrelated files are modified. What best keeps the next commit focused?","hint":"A focused commit starts by staging only the file or files that serve the same purpose.","help":{"concept":"Build the next snapshot one purpose at a time, review the staged version, and reverse a staging decision without losing work.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"Stage only the changes that serve one shared purpose.","b":"To commit changes automatically","c":"To discard every working-tree change","d":"To list the recorded commit history"}},"multi-choice-1":{"title":"A Coherent Snapshot","prompt":"Which practices help keep a commit focused? Select all that apply.","hint":"Judge each option independently; choose only the statements that stay true in this exact repository state.","help":{"concept":"Build the next snapshot one purpose at a time, review the staged version, and reverse a staging decision without losing work.","hint_1":"A partly true option is still wrong if it adds an effect Git does not guarantee.","hint_2":"Use the layer named in the prompt—working tree, staging area, or history—to test each choice."},"options":{"a":"Stage files that serve the same project result.","b":"Review the staged snapshot before committing.","c":"Stage every changed file so status becomes quiet.","d":"Use a subject that describes the result."}},"multi-choice-2":{"title":"Inspect the Staged Boundary","prompt":"Which commands can help verify what is staged?","hint":"Choose the one answer that describes this command or concept precisely.","help":{"concept":"Build the next snapshot one purpose at a time, review the staged version, and reverse a staging decision without losing work.","hint_1":"Remove choices that act on a different repository layer or promise behavior Git does not provide.","hint_2":"Prefer the exact definition used in this chapter over a nearby Git idea."},"options":{"a":"git diff --staged","b":"git diff --staged --name-only","c":"git status --short","d":"git init"}},"fill-blank-1":{"title":"Write a Focused Commit Subject","prompt":"The staged change expands the community cleanup time. Complete the subject: `git commit -m \"[blank1]\"`.","hint":"Choose the term or symbol that matches the exact state described, not a nearby Git concept.","help":{"concept":"Build the next snapshot one purpose at a time, review the staged version, and reverse a staging decision without losing work.","hint_1":"Pay attention to whether the prompt describes an untracked path, a working-tree edit, staged work, or history.","hint_2":"Read spaces, punctuation, and status columns as meaningful when the question shows Git output."},"template":"git commit -m \"[blank1]\"","choices":["Update community cleanup time","changes","update files","work in progress"]}}}},"git-foundations-module-3-manage-tracked-files":{"ignore-generated-files":{"label":"Keep Generated Files Out of History","summary":"Add one generated file, introduce one ignore rule, and stop tracking generated output safely.","cards":{"sketch0":{"title":"Ignore Rules Describe Untracked Noise"},"sketch2":{"title":"Tracked Files Need an Extra Step"},"sketch3":{"title":"The Policy Is Project Source"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_ignore_generated_files_sketch0":{"title":"Add a Generated Summary Once","prompt":"To simulate output from the project’s summary tool, create `community-project/generated/summary.txt`. Starting on line 1, enter exactly:\n\n```text\nGenerated summary\n\nCreated automatically from project notes.\n```\n\nSave the file. Then use the terminal to:\n\n1. Inspect the short status and confirm that Git identifies the new file.\n2. Stage only `generated/summary.txt`.\n3. Create a commit with the exact message `Add generated summary`.\n\nThe next steps will reconsider whether an automatically generated file should remain tracked.\n","hint":"Create the supplied generated file and record it so the next lesson can correct that tracking decision.","help":{"concept":"Git can track any text file, even one that can be regenerated. This step intentionally records the summary so you can later learn why an ignore rule alone does not stop tracking an existing path.","hint_1":"Do not create any other generated file yet.","hint_2":"The commit should add only `generated/summary.txt`."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git status --short\ngit add generated/summary.txt\ngit commit -m \"Add generated summary\"","instructions":"Create `community-project/generated/summary.txt`. Starting on line 1, enter exactly three lines: `Generated summary`, a blank line, and `Created automatically from project notes.` Save it. Inspect short status, stage the file, and commit it with the message `Add generated summary`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$58"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$59"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the new generated summary?"},"1":{"message":"Did you stage only the generated summary?"},"2":{"message":"Did you record the generated summary once?"}}}},"try_ignore_generated_files_sketch2":{"title":"Apply the Ignore Rule to Tracked Output","prompt":"$5a","hint":"Track the policy, remove only the summary’s index entry, and verify that the local file is now ignored.","help":{"concept":"A `.gitignore` line containing `generated/` matches untracked files in that folder. Because `summary.txt` was already tracked, `git rm --cached generated/summary.txt` is also required. `--cached` removes the index entry while preserving the working file.","hint_1":"Do not use plain `git rm`, which would delete the local file.","hint_2":"The ignored summary should appear with `!!` when ignored paths are shown."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git add .gitignore\ngit rm --cached generated/summary.txt\ngit status --short --ignored","instructions":"Create `community-project/.gitignore` with exactly `generated/` on line 1. Save it. Stage `.gitignore`, then stop tracking `generated/summary.txt` without deleting its local file. Inspect status with ignored paths included. Do not commit yet.","starterFiles":{"zoeskoul_setup_sh":{"content":"$5b"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$5c"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the ignore policy?"},"1":{"message":"Did you stop tracking the summary without deleting it?"},"2":{"message":"Did you verify that the local summary is now ignored?"}}}},"try_ignore_generated_files_sketch3":{"title":"Record the Ignore Policy","prompt":"Record the staged changes with the exact commit message:\n\n```bash\ngit commit -m \"Ignore generated output\"\n```\n\nThen inspect the normal short status.\n\nA clean result confirms that the ignore policy was committed and that no tracked changes remain unfinished. The generated summary still exists on the local computer, but Git now leaves it out of ordinary status results and future staging.","hint":"Commit the prepared policy change and verify the tracked state.","help":{"concept":"`git commit -m \"Ignore generated output\"` records `.gitignore` and removes the generated summary from the current tracked snapshot. The local summary remains on disk, ignored by the new rule.","hint_1":"Do not delete `generated/summary.txt`.","hint_2":"Normal short status should produce no entries."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git commit -m \"Ignore generated output\"\ngit status --short","instructions":"The ignore policy and generated-file untracking are staged. Record them with the message `Ignore generated output`, then confirm that normal short status is clean.","starterFiles":{"zoeskoul_setup_sh":{"content":"$5d"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$5e"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the ignore policy and tracked-file cleanup?"},"1":{"message":"Did you verify that normal status is clean?"}}}}},"practice":{"ignore-generated-files-single-choice-0":{"title":"Purpose of .gitignore","prompt":"What is the primary purpose of a `.gitignore` file in a Git repository?","hint":"A `.gitignore` rule prevents matching untracked paths from entering ordinary staging and status workflows.","help":{"concept":"Write narrow ignore rules, prove which rule matches, and separate “ignored” from “already tracked.”","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"To track changes in all files","b":"To ignore specific files and directories","c":"To delete files from the repository","d":"To rename files in the repository"}},"ignore-generated-files-single-choice-1":{"title":"Effect of Adding to .gitignore","prompt":"What happens when you add a file to `.gitignore` that has already been committed?","hint":"Ignore rules do not retroactively untrack a file that is already part of repository history.","help":{"concept":"Write narrow ignore rules, prove which rule matches, and separate “ignored” from “already tracked.”","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"The file is automatically deleted from the repository","b":"The file is untracked and removed from history","c":"The file remains tracked and in history","d":"The file is renamed in the repository"}},"ignore-generated-files-multi-choice-0":{"title":"Verify the Ignore Policy","prompt":"Which statements describe the generated-file policy in this lesson? Select all that apply.","hint":"Separate the local file from Git tracking: the summary stays on disk while the ignore rule keeps it out of future snapshots.","help":{"concept":"Write narrow ignore rules, prove which rule matches, and separate “ignored” from “already tracked.”","hint_1":"A partly true option is still wrong if it adds an effect Git does not guarantee.","hint_2":"Use the layer named in the prompt—working tree, staging area, or history—to test each choice."},"options":{"a":"`.gitignore` contains the rule `generated/`.","b":"`generated/summary.txt` remains available locally.","c":"`git rm --cached` deletes the local summary from disk.","d":"Ignored files still appear in ordinary `git status --short` output."}},"ignore-generated-files-drag-reorder-0":{"title":"Stop Tracking a Local-Only File","prompt":"Arrange the safe steps for a file that is already tracked but should remain only on each developer’s machine.","hint":"Start with the state that must exist before the next action can make sense.","help":{"concept":"Write narrow ignore rules, prove which rule matches, and separate “ignored” from “already tracked.”","hint_1":"Track how the project moves from working files to a proposed snapshot and then to history.","hint_2":"Read the ordered steps as one continuous repository story."},"tokens":{"t1":"Add a narrow ignore rule","t2":"Remove the path from Git’s index while keeping the working copy","t3":"Commit the policy change"}}}},"module-3-clean-release-snapshot":{"label":"Module Project: Clean the Volunteer Project Repository","summary":"Finish volunteer-project with path cleanup, one ignore rule, safe recovery, and a clean handoff.","cards":{"sketch0":{"title":"Finish Volunteer Project Cleanly"},"project":{"title":"Prepare the Volunteer Project Handoff"}},"projectSteps":{"try_module_3_sketch0":{"title":"Rename Assignments to Roles"},"try_module_3_sketch1":{"title":"Remove the Obsolete Schedule"},"try_module_3_sketch2":{"title":"Write the Exact Ignore File"},"try_module_3_sketch3":{"title":"Stage the Ignore Policy"},"try_module_3_sketch4":{"title":"Create and Recover a README Mistake"},"try_module_3_sketch5":{"title":"Commit and Verify the Volunteer Project Handoff"}},"moduleProject":{"steps":{"try_module_3_sketch0":{"title":"Add the Generated Volunteer Report","prompt":"Create `volunteer-project/generated/report.txt` with exactly three lines: `Generated volunteer report`, a blank line, and `Prepared automatically from assignments.` Save it, stage it, and commit it with the message `Add generated report`.","hint":"Record the supplied generated file once so you can later correct the tracking policy.","help":{"concept":"This mirrors the guided project: a generated file can be committed, but a later ignore policy should keep regeneratable output outside future snapshots.","hint_1":"Do not change the three existing project files.","hint_2":"The commit should add only the report."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git status --short\ngit add generated/report.txt\ngit commit -m \"Add generated report\"","instructions":"Create `volunteer-project/generated/report.txt` with exactly three lines: `Generated volunteer report`, a blank line, and `Prepared automatically from assignments.` Save it, stage it, and commit it with the message `Add generated report`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$5f"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$60"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the new report?"},"1":{"message":"Did you stage only the report?"},"2":{"message":"Did you record the generated report once?"}}}},"try_module_3_sketch1":{"title":"Rename Assignments to Roles","prompt":"Rename tracked `assignments.txt` to `roles.txt` with Git.","hint":"Use the Git-aware move for the tracked path.","help":{"concept":"`git mv assignments.txt roles.txt` renames the file and stages the path change together.","hint_1":"Keep it in the repository root.","hint_2":"Do not edit its text."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git mv assignments.txt roles.txt","instructions":"Rename tracked `assignments.txt` to `roles.txt` with Git.","starterFiles":{"zoeskoul_setup_sh":{"content":"$61"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$62"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you rename the tracked assignment list to `roles.txt`?"}}}},"try_module_3_sketch2":{"title":"Remove the Obsolete Meeting-Time File","prompt":"The orientation schedule has been moved elsewhere. Remove tracked `meeting-times.txt`, then inspect the staged name-status summary.","hint":"Stage the removal and review it with the rename.","help":{"concept":"`git rm meeting-times.txt` deletes and stages the tracked path. `git diff --staged --name-status` shows the intended rename and removal before the final commit.","hint_1":"Do not remove `README.md` or `roles.txt`.","hint_2":"Leave the cleanup staged."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git rm meeting-times.txt\ngit diff --staged --name-status","instructions":"The orientation schedule has been moved elsewhere. Remove tracked `meeting-times.txt`, then inspect the staged name-status summary.","starterFiles":{"zoeskoul_setup_sh":{"content":"$63"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$64"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the obsolete meeting-time removal?"},"1":{"message":"Did you review the staged path cleanup?"}}}},"try_module_3_sketch3":{"title":"Apply the Volunteer Ignore Policy","prompt":"Create `volunteer-project/.gitignore` with exactly `generated/` on line 1. Save it. Stage `.gitignore`, stop tracking `generated/report.txt` without deleting it, and inspect status with ignored paths included.","hint":"Add the policy, preserve the local report, and keep the earlier rename and removal staged.","help":{"concept":"`git rm --cached generated/report.txt` removes the tracked relationship while preserving the working file. The `generated/` rule then classifies that local report as ignored.","hint_1":"Do not stage the generated report again.","hint_2":"The staged set should contain the rename, removal, `.gitignore`, and report untracking."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git add .gitignore\ngit rm --cached generated/report.txt\ngit status --short --ignored","instructions":"Create `volunteer-project/.gitignore` with exactly `generated/` on line 1. Save it. Stage `.gitignore`, stop tracking `generated/report.txt` without deleting it, and inspect status with ignored paths included.","starterFiles":{"zoeskoul_setup_sh":{"content":"$65"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$66"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the volunteer ignore policy?"},"1":{"message":"Did you stop tracking the report without deleting it?"},"2":{"message":"Did you verify that the local report is ignored?"}}}},"try_module_3_sketch4":{"title":"Recover an Accidental README Rewrite","prompt":"Open `volunteer-project/README.md`. Find `Assignments and meeting times.` and replace it with `Accidental release rewrite.` Save the file. Stage the mistake, unstage it without losing the working copy, then restore the committed README. Finally inspect the staged name-status summary; only the intended maintenance work should remain.","hint":"Recover the staging layer first and the working-tree layer second.","help":{"concept":"`git restore --staged README.md` removes the mistake from the proposal; `git restore README.md` then repairs the working file. Other staged paths remain untouched.","hint_1":"Do not clear the rename, removal, or ignore-policy changes.","hint_2":"The final staged summary should not include README.md."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git add README.md\ngit restore --staged README.md\ngit restore README.md\ngit diff --staged --name-status","instructions":"Open `volunteer-project/README.md`. Find `Assignments and meeting times.` and replace it with `Accidental release rewrite.` Save the file. Stage the mistake, unstage it without losing the working copy, then restore the committed README. Finally inspect the staged name-status summary; only the intended maintenance work should remain.","starterFiles":{"zoeskoul_setup_sh":{"content":"$67"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$68"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the supplied README mistake?"},"1":{"message":"Did you unstage only the README?"},"2":{"message":"Did you restore the README working copy?"},"3":{"message":"Did you verify the intended maintenance snapshot?"}}}},"try_module_3_sketch5":{"title":"Commit and Verify the Volunteer Handoff","prompt":"Record the prepared maintenance snapshot with the message `Prepare volunteer project handoff`. Then inspect concise history, the newest commit summary, and final short status.","hint":"Commit the staged maintenance work and audit the handoff.","help":{"concept":"`git commit` records the rename, removal, ignore policy, and generated-report untracking together. The history and status commands verify the final repository.","hint_1":"The ignored report and preview remain local.","hint_2":"Normal short status should be empty."},"starterCode":"# Volunteer Project\n\nAssignments and meeting times.\n","solutionCode":"git commit -m \"Prepare volunteer project handoff\"\ngit log --oneline\ngit show --stat --oneline HEAD\ngit status --short","instructions":"Record the prepared maintenance snapshot with the message `Prepare volunteer project handoff`. Then inspect concise history, the newest commit summary, and final short status.","starterFiles":{"zoeskoul_setup_sh":{"content":"$69"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$6a"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the volunteer maintenance snapshot?"},"1":{"message":"Did you inspect the final history?"},"2":{"message":"Did you inspect the final snapshot summary?"},"3":{"message":"Did you verify the clean tracked state?"}}}}},"description":"Finish the same volunteer-project repository with one generated report, one rename, one removal, one ignore rule, and one safe recovery.","title":"Prepare the Volunteer Project Handoff"}},"module-3-volunteer-project-maintenance":{"label":"Module Project: Clean the Volunteer Project Repository","summary":"Finish volunteer-project with path cleanup, one ignore rule, safe recovery, and a clean handoff.","cards":{"sketch0":{"title":"Finish Volunteer Project Cleanly"},"project":{"title":"Prepare the Volunteer Project Handoff"}},"projectSteps":{"try_module_3_sketch0":{"title":"Rename Assignments to Roles"},"try_module_3_sketch1":{"title":"Remove the Obsolete Schedule"},"try_module_3_sketch2":{"title":"Write the Exact Ignore File"},"try_module_3_sketch3":{"title":"Stage the Ignore Policy"},"try_module_3_sketch4":{"title":"Create and Recover a README Mistake"},"try_module_3_sketch5":{"title":"Commit and Verify the Volunteer Project Handoff"}},"moduleProject":{"steps":{"try_module_3_sketch0":{"title":"Add the Generated Volunteer Report","prompt":"To simulate output from a volunteer reporting tool, create `volunteer-project/generated/report.txt` with exactly three lines: `Generated volunteer report`, a blank line, and `Prepared automatically from assignments.` Save it, stage it, and commit it with the message `Add generated report`.","hint":"Record the supplied generated file once so you can later correct the tracking policy.","help":{"concept":"This mirrors the guided project: a generated file can be committed, but a later ignore policy should keep regeneratable output outside future snapshots.","hint_1":"Do not change the three existing project files.","hint_2":"The commit should add only the report."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git status --short\ngit add generated/report.txt\ngit commit -m \"Add generated report\"","instructions":"To simulate output from a volunteer reporting tool, create `volunteer-project/generated/report.txt` with exactly three lines: `Generated volunteer report`, a blank line, and `Prepared automatically from assignments.` Save it, stage it, and commit it with the message `Add generated report`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$6b"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$6c"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the new report?"},"1":{"message":"Did you stage only the report?"},"2":{"message":"Did you record the generated report once?"}}}},"try_module_3_sketch1":{"title":"Rename Assignments to Roles","prompt":"The volunteer team now treats these entries as ongoing roles rather than one-time assignments, so `roles.txt` is a clearer name. Rename tracked `assignments.txt` to `roles.txt` with Git.","hint":"Use the Git-aware move for the tracked path.","help":{"concept":"`git mv assignments.txt roles.txt` renames the file and stages the path change together.","hint_1":"Keep it in the repository root.","hint_2":"Do not edit its text."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git mv assignments.txt roles.txt","instructions":"The volunteer team now treats these entries as ongoing roles rather than one-time assignments, so `roles.txt` is a clearer name. Rename tracked `assignments.txt` to `roles.txt` with Git.","starterFiles":{"zoeskoul_setup_sh":{"content":"$6d"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$6e"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you rename the tracked assignment list to `roles.txt`?"}}}},"try_module_3_sketch2":{"title":"Remove the Obsolete Meeting-Time File","prompt":"The orientation schedule has been moved elsewhere. Remove tracked `meeting-times.txt`, then inspect the staged name-status summary.","hint":"Stage the removal and review it with the rename.","help":{"concept":"`git rm meeting-times.txt` deletes and stages the tracked path. `git diff --staged --name-status` shows the intended rename and removal before the final commit.","hint_1":"Do not remove `README.md` or `roles.txt`.","hint_2":"Leave the cleanup staged."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git rm meeting-times.txt\ngit diff --staged --name-status","instructions":"The orientation schedule has been moved elsewhere. Remove tracked `meeting-times.txt`, then inspect the staged name-status summary.","starterFiles":{"zoeskoul_setup_sh":{"content":"$6f"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$70"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the obsolete meeting-time removal?"},"1":{"message":"Did you review the staged path cleanup?"}}}},"try_module_3_sketch3":{"title":"Apply the Volunteer Ignore Policy","prompt":"Create `volunteer-project/.gitignore` with exactly `generated/` on line 1. Save it. Stage `.gitignore`, stop tracking `generated/report.txt` without deleting it, and inspect status with ignored paths included.","hint":"Add the policy, preserve the local report, and keep the earlier rename and removal staged.","help":{"concept":"`git rm --cached generated/report.txt` removes the tracked relationship while preserving the working file. The `generated/` rule then classifies that local report as ignored.","hint_1":"Do not stage the generated report again.","hint_2":"The staged set should contain the rename, removal, `.gitignore`, and report untracking."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git add .gitignore\ngit rm --cached generated/report.txt\ngit status --short --ignored","instructions":"Create `volunteer-project/.gitignore` with exactly `generated/` on line 1. Save it. Stage `.gitignore`, stop tracking `generated/report.txt` without deleting it, and inspect status with ignored paths included.","starterFiles":{"zoeskoul_setup_sh":{"content":"$71"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$72"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the volunteer ignore policy?"},"1":{"message":"Did you stop tracking the report without deleting it?"},"2":{"message":"Did you verify that the local report is ignored?"}}}},"try_module_3_sketch4":{"title":"Recover an Accidental README Rewrite","prompt":"Open `volunteer-project/README.md`. Find `Volunteer coordination notes.` and replace it with `Accidental release rewrite.` Save the file. Stage the mistake, unstage it without losing the working copy, then restore the committed README. Finally inspect the staged name-status summary; only the intended maintenance work should remain.","hint":"Recover the staging layer first and the working-tree layer second.","help":{"concept":"`git restore --staged README.md` removes the mistake from the proposal; `git restore README.md` then repairs the working file. Other staged paths remain untouched.","hint_1":"Do not clear the rename, removal, or ignore-policy changes.","hint_2":"The final staged summary should not include README.md."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git add README.md\ngit restore --staged README.md\ngit restore README.md\ngit diff --staged --name-status","instructions":"Open `volunteer-project/README.md`. Find `Volunteer coordination notes.` and replace it with `Accidental release rewrite.` Save the file. Stage the mistake, unstage it without losing the working copy, then restore the committed README. Finally inspect the staged name-status summary; only the intended maintenance work should remain.","starterFiles":{"zoeskoul_setup_sh":{"content":"$73"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$74"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the supplied README mistake?"},"1":{"message":"Did you unstage only the README?"},"2":{"message":"Did you restore the README working copy?"},"3":{"message":"Did you verify the intended maintenance snapshot?"}}}},"try_module_3_sketch5":{"title":"Commit and Verify the Volunteer Handoff","prompt":"Record the prepared maintenance snapshot with the message `Prepare volunteer project handoff`. Then inspect concise history, the newest commit summary, and final short status.","hint":"Commit the staged maintenance work and audit the handoff.","help":{"concept":"`git commit` records the rename, removal, ignore policy, and generated-report untracking together. The history and status commands verify the final repository.","hint_1":"The ignored report and preview remain local.","hint_2":"Normal short status should be empty."},"starterCode":"# Volunteer Project\n\nVolunteer coordination notes.\n","solutionCode":"git commit -m \"Prepare volunteer project handoff\"\ngit log --oneline\ngit show --stat --oneline HEAD\ngit status --short","instructions":"Record the prepared maintenance snapshot with the message `Prepare volunteer project handoff`. Then inspect concise history, the newest commit summary, and final short status.","starterFiles":{"zoeskoul_setup_sh":{"content":"$75"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$76"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the volunteer maintenance snapshot?"},"1":{"message":"Did you inspect the final history?"},"2":{"message":"Did you inspect the final snapshot summary?"},"3":{"message":"Did you verify the clean tracked state?"}}}}},"description":"Finish the same volunteer-project repository with one generated report, one rename, one removal, one ignore rule, and one safe recovery.","title":"Prepare the Volunteer Project Handoff"}},"rename-and-remove-tracked-files":{"label":"Rename and Remove Tracked Files","summary":"Simplify community-project by renaming the schedule and removing the obsolete contact list.","cards":{"sketch0":{"title":"Tracked Paths Change with the Project"},"sketch1":{"title":"Structural Changes Need Review"},"sketch3":{"title":"Group One Cleanup Purpose"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_rename_and_remove_tracked_files_sketch0":{"title":"Rename the Tracked Schedule","prompt":"Rename the tracked file by running:\n\n```bash\ngit mv schedule.txt events.txt\n```\n\nThis command renames the file in the working tree and stages the path change in one action. Git does not store a permanent rename object; when it compares snapshots, it recognizes that the same content moved from one path to another.\n\nLeave the staged rename uncommitted so you can review it with the next project change.\n","hint":"Use the Git-aware move for the tracked path.","help":{"concept":"`git mv schedule.txt events.txt` renames the working file and stages the path change in one action. Git records the before-and-after snapshots rather than storing a special rename object.","hint_1":"Keep the file in the repository root.","hint_2":"Do not edit its text."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git mv schedule.txt events.txt","starterFiles":{"zoeskoul_setup_sh":{"content":"$77"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$78"}},"instructions":"The project now calls its schedule `events.txt`. Rename tracked `schedule.txt` to `events.txt` with Git so the path change is staged.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you rename the tracked schedule to `events.txt`?"}}}},"try_rename_and_remove_tracked_files_sketch1":{"title":"Remove the Obsolete Contact List","prompt":"Remove the tracked file by running:\n\n```bash\ngit rm contacts.txt\n```\n\nThis command deletes `contacts.txt` from the working tree and stages its removal in one action.\n\nThen inspect all staged path changes by running:\n\n```bash\ngit diff --staged --name-status\n```\n\nThe summary should show the removal of `contacts.txt` together with the staged rename from `schedule.txt` to `events.txt`. Git uses status letters such as `D` for a deleted file and `R` when it recognizes a likely rename.\n\nLeave both staged changes uncommitted.\n","hint":"Stage the tracked removal and review both structural changes.","help":{"concept":"`git rm contacts.txt` deletes the working file and stages its removal. `git diff --staged --name-status` summarizes staged path changes with status letters such as `D` for deletion and `R` for a likely rename.","hint_1":"Do not remove `README.md` or `events.txt`.","hint_2":"The summary should contain the rename and the contact removal."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git rm contacts.txt\ngit diff --staged --name-status","starterFiles":{"zoeskoul_setup_sh":{"content":"$79"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$7a"}},"instructions":"The contact list is no longer maintained in this project. Remove tracked `contacts.txt` with Git, then inspect the staged name-status summary together with the schedule rename.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the obsolete contact-list removal?"},"1":{"message":"Did you review both staged path changes?"}}}},"try_rename_and_remove_tracked_files_sketch3":{"title":"Commit the Structural Cleanup","prompt":"Record the staged changes with the exact commit message:\n\n```bash\ngit commit -m \"Organize community project files\"\n```\n\nThen run the short-status command to verify that no unfinished changes remain.\n\nA clean result confirms that the rename to `events.txt` and the removal of `contacts.txt` were both recorded successfully.\n","hint":"Commit the one-purpose path cleanup and verify the result.","help":{"concept":"`git commit -m ...` records the staged repository shape. `git status --short` then confirms that the working tree and staging area match the new snapshot.","hint_1":"Use the exact commit message.","hint_2":"The project should now contain only `README.md` and `events.txt`."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git commit -m \"Organize community project files\"\ngit status --short","starterFiles":{"zoeskoul_setup_sh":{"content":"$7b"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$7c"}},"instructions":"Record the staged rename and removal with the message `Organize community project files`. Then confirm that short status is clean.","terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the structural cleanup?"},"1":{"message":"Did you verify a clean state afterward?"}}}}},"practice":{"single-choice-1":{"title":"Purpose of git mv","prompt":"What is the primary purpose of the `git mv` command?","hint":"`git mv` combines a working-tree path change with staging that change.","help":{"concept":"Use Git-aware structural operations, review the staged paths, and record a cleanup without losing earlier versions.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"To move a file without tracking","b":"To rename a file and stage the change","c":"To delete a file","d":"To create a new file"}},"single-choice-2":{"title":"Effect of git rm","prompt":"What happens when you use the `git rm` command?","hint":"`git rm` removes the working file and prepares that deletion for the next commit.","help":{"concept":"Use Git-aware structural operations, review the staged paths, and record a cleanup without losing earlier versions.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"The file is moved to a new location","b":"The file is removed from the working tree and staged for deletion","c":"The file is renamed","d":"The file is ignored"}},"multi-choice-1":{"title":"Commands to Verify Staged Changes","prompt":"Which commands can you use to verify staged changes before committing?","hint":"Judge each option independently; choose only the statements that stay true in this exact repository state.","help":{"concept":"Use Git-aware structural operations, review the staged paths, and record a cleanup without losing earlier versions.","hint_1":"A partly true option is still wrong if it adds an effect Git does not guarantee.","hint_2":"Use the layer named in the prompt—working tree, staging area, or history—to test each choice."},"options":{"a":"git status","b":"git diff","c":"git diff --staged","d":"git log"}},"drag-reorder-1":{"title":"Steps to Rename and Commit a File","prompt":"Arrange the steps to rename a file and commit the change using Git.","hint":"Start with the state that must exist before the next action can make sense.","help":{"concept":"Use Git-aware structural operations, review the staged paths, and record a cleanup without losing earlier versions.","hint_1":"Track how the project moves from working files to a proposed snapshot and then to history.","hint_2":"Read the ordered steps as one continuous repository story."},"tokens":{"t1":"Use git mv to rename the file","t2":"Check the status with git status","t3":"Commit the change with git commit"}}}},"restore-without-rewriting-history":{"label":"Recover from Everyday Mistakes","summary":"Restore one unstaged mistake and one staged mistake without rewriting history.","cards":{"sketch0":{"title":"Restore the Layer You Intend"},"sketch1":{"title":"Unstage Without Losing the File"},"sketch2":{"title":"A Staged Mistake May Need Two Actions"},"quiz":{"title":"Practice"}},"tryIt":{"allowReveal":true,"try_restore_without_rewriting_history_sketch0":{"title":"Restore an Unstaged README Mistake","prompt":"Open `community-project/README.md` and find:\n\n`Shared community activities and updates.`\n\nReplace it with:\n\n`Accidental rewrite.`\n\nSave the file. Before undoing anything, inspect the unstaged change in `README.md` so you can see exactly what would be discarded.\n\nThen restore the file:\n\n```bash\ngit restore README.md\n```\n\nBy default, `git restore` replaces the working copy with the version currently in the staging area. In this exercise, that staged version matches the current commit, so the accidental rewrite is removed and the committed README returns.\n\nThis command is useful when an unstaged edit is unwanted, but use it carefully: it discards the local change rather than saving it for later.\n\nFinally, inspect the short status and confirm that no tracked change remains.\n","hint":"Review the mistake first, then restore only the working-tree copy.","help":{"concept":"`git restore README.md` replaces the unstaged working copy with the version from the current commit. It does not create, delete, or rewrite earlier commits.","hint_1":"Use `git diff -- README.md` before restoring so you can see what will be discarded.","hint_2":"Ignored generated files may remain on disk without appearing in normal status."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git diff -- README.md\ngit restore README.md\ngit status --short","instructions":"Open `community-project/README.md`. Find `Shared community activities and updates.` and replace it with `Accidental rewrite.` Save the file. Inspect its unstaged diff, restore the committed README, and confirm with short status that no tracked change remains.","starterFiles":{"zoeskoul_setup_sh":{"content":"$7d"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$7e"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the README mistake before discarding it?"},"1":{"message":"Did you restore only the README working copy?"},"2":{"message":"Did you verify that no tracked change remains?"}}}},"try_restore_without_rewriting_history_sketch1":{"title":"Stage and Unstage an Events Mistake","prompt":"Open `community-project/events.txt` and find:\n\n`Saturday cleanup: 9:30 AM`\n\nReplace it with:\n\n`Saturday cleanup: midnight`\n\nSave the file, then stage the change:\n\n```bash\ngit add events.txt\n```\n\nAt this point, the mistaken edit is part of the proposed next snapshot.\n\nRemove it from the staging area by running:\n\n```bash\ngit restore --staged events.txt\n```\n\nThe `--staged` option changes only the staging layer. The edit remains in the working copy of `events.txt`, but it is no longer prepared for the next commit.\n\nDo not restore the file’s text yet.","hint":"Stage the supplied mistake, then correct only the staging layer.","help":{"concept":"`git restore --staged events.txt` replaces the staged version with the version from `HEAD` while preserving the current working-tree text. The unwanted edit therefore remains visible but unstaged.","hint_1":"Do not run plain `git restore events.txt` in this step.","hint_2":"The next exercise will restore the working copy."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git add events.txt\ngit restore --staged events.txt","instructions":"Open `community-project/events.txt`. Find `Saturday cleanup: 9:30 AM` and replace it with `Saturday cleanup: midnight`. Save the file. Stage the mistake, then remove it from the staging area without changing the working file. Do not restore the text yet.","starterFiles":{"zoeskoul_setup_sh":{"content":"$7f"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$80"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the supplied events mistake?"},"1":{"message":"Did you unstage it without changing the working file?"}}}},"try_restore_without_rewriting_history_sketch2":{"title":"Restore the Remaining Events Mistake","prompt":"Now discard that unwanted edit and restore the file to the version stored in the current commit:\n\n```bash\ngit restore events.txt\n```\n\nThis second restore changes the working file itself. Together, the two commands correct the mistake in separate steps:\n\n* `git restore --staged events.txt` removed the change from the proposed snapshot.\n* `git restore events.txt` discarded the remaining working-tree edit.\n\nFinally, inspect the short status and confirm that no tracked changes remain unfinished.\n","hint":"Now correct the working-tree layer.","help":{"concept":"`git restore events.txt` replaces the remaining unstaged edit with the committed version. Because the staging area is already clean, one restore command completes the recovery.","hint_1":"The restored line should return to `Saturday cleanup: 9:30 AM`.","hint_2":"Normal short status should be empty."},"starterCode":"# Community Project\n\nShared community activities and updates.\n","solutionCode":"git restore events.txt\ngit status --short","instructions":"The incorrect midnight time remains unstaged in `events.txt`. Restore the committed file, then confirm that short status has no unfinished tracked changes.","starterFiles":{"zoeskoul_setup_sh":{"content":"$81"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$82"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you restore the remaining working-tree mistake?"},"1":{"message":"Did you verify the clean tracked state?"}}}}},"practice":{"single-choice-1":{"title":"Purpose of git restore","prompt":"What is the primary purpose of `git restore path` in this course?","hint":"Without `--staged`, `git restore` replaces an unwanted working-tree edit with the recorded version.","help":{"concept":"Correct working-tree and staging mistakes at the right layer while leaving existing commits untouched.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"To discard an unwanted working-tree edit","b":"To record a new commit","c":"To stage an untracked file","d":"To list earlier commits"}},"single-choice-2":{"title":"Effect of git restore --staged","prompt":"What happens when you use `git restore --staged` on a file?","hint":"The `--staged` option changes the staging area while preserving the current working-tree text.","help":{"concept":"Correct working-tree and staging mistakes at the right layer while leaving existing commits untouched.","hint_1":"Remove options that act on a different repository layer than the one named in the question.","hint_2":"Choose the answer that remains accurate even when other unrelated files exist."},"options":{"a":"The file is removed from the staging area but changes are kept","b":"The file is deleted from the repository","c":"The file is committed to the repository","d":"The file is reverted to the last committed state"}},"multi-choice-1":{"title":"Choosing the Correct Restore Command","prompt":"Which commands can discard an unwanted working-tree edit and unstage a file?","hint":"Judge each option independently; choose only the statements that stay true in this exact repository state.","help":{"concept":"Correct working-tree and staging mistakes at the right layer while leaving existing commits untouched.","hint_1":"A partly true option is still wrong if it adds an effect Git does not guarantee.","hint_2":"Use the layer named in the prompt—working tree, staging area, or history—to test each choice."},"options":{"a":"git restore","b":"git restore --staged","c":"git commit","d":"git add"}},"drag-reorder-1":{"title":"Discard a Change That Is Already Staged","prompt":"Arrange the safe correction steps for a file whose accidental rewrite is both staged and present in the working tree.","hint":"Start with the state that must exist before the next action can make sense.","help":{"concept":"Correct working-tree and staging mistakes at the right layer while leaving existing commits untouched.","hint_1":"Track how the project moves from working files to a proposed snapshot and then to history.","hint_2":"Read the ordered steps as one continuous repository story."},"tokens":{"t1":"Remove the accidental version from the staging area","t2":"Restore the working file from the recorded version"}}}}},"git-foundations-module-4-final-capstone":{"final-neighborhood-resource-guide-history":{"label":"Final Capstone: Neighborhood Guide History","summary":"Build a compact four-file baseline and a clean four-commit local history.","cards":{"sketch0":{"title":"Fresh Repository, Independent Transfer"},"project":{"title":"Complete the Neighborhood Guide Capstone"}},"projectSteps":{"try_final_neighborhood_resource_guide_history_sketch0":{"title":"Initialize and Record the Baseline"},"try_final_neighborhood_resource_guide_history_sketch1":{"title":"Add the Neighborhood Resources File"},"try_final_neighborhood_resource_guide_history_sketch2":{"title":"Update the Help Desk Hours"},"try_final_neighborhood_resource_guide_history_sketch3":{"title":"Add the Generated-File Policy"},"try_final_neighborhood_resource_guide_history_sketch4":{"title":"Clean Tracked Paths and Recover a Mistake"},"try_final_neighborhood_resource_guide_history_sketch5":{"title":"Commit and Audit the Final Handoff"}},"finalCapstone":{"steps":{"try_final_neighborhood_resource_guide_history_sketch0":{"title":"Initialize and Record the Guide Baseline","prompt":"Inside `neighborhood-guide/`, initialize a repository on `main` and store the supplied local author name and email. Stage the four baseline text files—`README.md`, `services.txt`, `hours.txt`, and `old-contacts.txt`—then record them with the message `Start neighborhood guide`.","hint":"Build the first snapshot from the four supplied text files.","help":{"concept":"This capstone combines the Module 1 workflow: initialize, configure local identity, stage the named files, and commit the first snapshot. No programming knowledge is involved.","hint_1":"Use the exact four paths and supplied identity.","hint_2":"Do not create additional files in this step."},"starterCode":"# Neighborhood Guide\n\nLocal services and opening hours.\n","solutionCode":"git init -b main\ngit config --local user.name \"ZoeSkoul Learner\"\ngit config --local user.email \"learner@zoeskoul.local\"\ngit add README.md services.txt hours.txt old-contacts.txt\ngit commit -m \"Start neighborhood guide\"","instructions":"Inside `neighborhood-guide/`, initialize a repository on `main` and store the supplied local author name and email. Stage the four baseline text files—`README.md`, `services.txt`, `hours.txt`, and `old-contacts.txt`—then record them with the message `Start neighborhood guide`.","starterFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- neighborhood-guide\nmkdir -p -- neighborhood-guide\nmkdir -p -- neighborhood-guide\nprintf %s '# Neighborhood Guide\n\nLocal services and opening hours.\n' > neighborhood-guide/README.md\nmkdir -p -- neighborhood-guide\nprintf %s 'Help desk hours: 10 AM - 4 PM\n' > neighborhood-guide/hours.txt\nmkdir -p -- neighborhood-guide\nprintf %s 'Old contact list\n\nRetired phone tree.\n' > neighborhood-guide/old-contacts.txt\nmkdir -p -- neighborhood-guide\nprintf %s 'Neighborhood services\n\nWelcome desk\nFood pantry\n' > neighborhood-guide/services.txt\n"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"#!/usr/bin/env bash\nset -eu\nrm -rf -- neighborhood-guide\nmkdir -p -- neighborhood-guide\nmkdir -p -- neighborhood-guide\nprintf %s '# Neighborhood Guide\n\nLocal services and opening hours.\n' > neighborhood-guide/README.md\nmkdir -p -- neighborhood-guide\nprintf %s 'Help desk hours: 10 AM - 4 PM\n' > neighborhood-guide/hours.txt\nmkdir -p -- neighborhood-guide\nprintf %s 'Old contact list\n\nRetired phone tree.\n' > neighborhood-guide/old-contacts.txt\nmkdir -p -- neighborhood-guide\nprintf %s 'Neighborhood services\n\nWelcome desk\nFood pantry\n' > neighborhood-guide/services.txt\n"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you initialize the guide on `main`?"},"1":{"message":"Did you store the supplied local name?"},"2":{"message":"Did you store the supplied local email?"},"3":{"message":"Did you stage the four baseline text files?"},"4":{"message":"Did you record the baseline with the requested message?"}}}},"try_final_neighborhood_resource_guide_history_sketch1":{"title":"Update the Neighborhood Services","prompt":"A neighborhood health clinic has joined the guide. Open `neighborhood-guide/services.txt`. Add `Health clinic` on a new line immediately after `Food pantry`. Save the file. Inspect the unstaged diff, stage the file, and commit it with the message `Update neighborhood services`.","hint":"Make the exact one-line addition and record it as one focused purpose.","help":{"concept":"`git diff -- services.txt` reviews the added service before staging. Staging and committing only that path creates a focused second snapshot without adding another project file.","hint_1":"Do not change the existing service lines.","hint_2":"The commit should affect only `services.txt`."},"starterCode":"# Neighborhood Guide\n\nLocal services and opening hours.\n","solutionCode":"git diff -- services.txt\ngit add services.txt\ngit commit -m \"Update neighborhood services\"","instructions":"A neighborhood health clinic has joined the guide. Open `neighborhood-guide/services.txt`. Add `Health clinic` on a new line immediately after `Food pantry`. Save the file. Inspect the unstaged diff, stage the file, and commit it with the message `Update neighborhood services`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$83"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$84"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the service-list change?"},"1":{"message":"Did you stage only the service list?"},"2":{"message":"Did you record the service update separately?"}}}},"try_final_neighborhood_resource_guide_history_sketch2":{"title":"Update the Help Desk Hours","prompt":"The help desk has expanded its weekday availability. Open `neighborhood-guide/hours.txt`. Replace `Help desk hours: 10 AM - 4 PM` with `Help desk hours: 9 AM - 5 PM`. Save the file. Inspect the unstaged diff, stage it, and commit it with the message `Update help desk hours`.","hint":"Review the exact hours change before recording it.","help":{"concept":"The same focused workflow applies: diff the single file, stage it by name, and commit it as its own purpose.","hint_1":"Do not edit another file.","hint_2":"The third commit should affect only `hours.txt`."},"starterCode":"# Neighborhood Guide\n\nLocal services and opening hours.\n","solutionCode":"git diff -- hours.txt\ngit add hours.txt\ngit commit -m \"Update help desk hours\"","instructions":"The help desk has expanded its weekday availability. Open `neighborhood-guide/hours.txt`. Replace `Help desk hours: 10 AM - 4 PM` with `Help desk hours: 9 AM - 5 PM`. Save the file. Inspect the unstaged diff, stage it, and commit it with the message `Update help desk hours`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$85"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$86"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you inspect the hours change?"},"1":{"message":"Did you stage only the hours file?"},"2":{"message":"Did you record the hours update separately?"}}}},"try_final_neighborhood_resource_guide_history_sketch3":{"title":"Clean Paths and Recover a README Mistake","prompt":"The guide now distinguishes community services from other future resources, and the retired phone tree is no longer distributed. Open `neighborhood-guide/README.md`. Replace `Local services and opening hours.` with `Accidental rewrite.` and save. Stage that mistake, rename tracked `services.txt` to `community-services.txt`, and remove tracked `old-contacts.txt`. Then unstage and restore only the README mistake. Inspect the staged name-status summary; it should contain the rename and removal, but not `README.md`.","hint":"Keep the intended path maintenance staged while recovering the accidental README edit.","help":{"concept":"Use `git mv` and `git rm` for the intended changes. Use `git restore --staged README.md` followed by `git restore README.md` to remove the mistake from both current layers without disturbing the other staged work.","hint_1":"Do not remove `hours.txt`.","hint_2":"The final staged summary should contain only the rename and removal."},"starterCode":"# Neighborhood Guide\n\nLocal services and opening hours.\n","solutionCode":"git add README.md\ngit mv services.txt community-services.txt\ngit rm old-contacts.txt\ngit restore --staged README.md\ngit restore README.md\ngit diff --staged --name-status","instructions":"The guide now distinguishes community services from other future resources, and the retired phone tree is no longer distributed. Open `neighborhood-guide/README.md`. Replace `Local services and opening hours.` with `Accidental rewrite.` and save. Stage that mistake, rename tracked `services.txt` to `community-services.txt`, and remove tracked `old-contacts.txt`. Then unstage and restore only the README mistake. Inspect the staged name-status summary; it should contain the rename and removal, but not `README.md`.","starterFiles":{"zoeskoul_setup_sh":{"content":"$87"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$88"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you stage the supplied README mistake?"},"1":{"message":"Did you stage the service-file rename?"},"2":{"message":"Did you stage the obsolete contact-list removal?"},"3":{"message":"Did you unstage only the README mistake?"},"4":{"message":"Did you restore the README working copy?"},"5":{"message":"Did you review the path-maintenance proposal?"}}}},"try_final_neighborhood_resource_guide_history_sketch4":{"title":"Add the Generated-File Policy","prompt":"A local preview is generated for review and should not become part of repository history. Create `neighborhood-guide/.gitignore` with exactly `generated/` on line 1. Create `neighborhood-guide/generated/preview.txt` containing `Temporary neighborhood preview.` Inspect status with ignored paths included, then stage only `.gitignore`. Keep the rename and removal staged.","hint":"Add one policy file and one ignored preview after the obsolete file has already been removed.","help":{"concept":"The `generated/` rule keeps the preview outside future snapshots. `git status --short --ignored` verifies it with `!!`, while `git add .gitignore` adds only the policy to the existing maintenance proposal.","hint_1":"Do not force-add the preview.","hint_2":"The staged set should contain the rename, removal, and `.gitignore`."},"starterCode":"# Neighborhood Guide\n\nLocal services and opening hours.\n","solutionCode":"git status --short --ignored\ngit add .gitignore","instructions":"A local preview is generated for review and should not become part of repository history. Create `neighborhood-guide/.gitignore` with exactly `generated/` on line 1. Create `neighborhood-guide/generated/preview.txt` containing `Temporary neighborhood preview.` Inspect status with ignored paths included, then stage only `.gitignore`. Keep the rename and removal staged.","starterFiles":{"zoeskoul_setup_sh":{"content":"$89"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$8a"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you verify the ignored preview?"},"1":{"message":"Did you stage only the ignore policy?"}}}},"try_final_neighborhood_resource_guide_history_sketch5":{"title":"Commit and Audit the Final Handoff","prompt":"Record the prepared maintenance snapshot with the message `Prepare neighborhood guide handoff`. Then inspect concise history, the newest commit summary, and final short status. The capstone should end with four focused commits and no unfinished tracked work.","hint":"Commit once, then verify timeline, latest snapshot, and current state.","help":{"concept":"The final commit records the ignore policy, service-file rename, and obsolete-file removal. The three inspection commands confirm the complete four-commit story and clean handoff.","hint_1":"The ignored preview remains on disk but outside normal status.","hint_2":"The newest commit should be the maintenance handoff."},"starterCode":"# Neighborhood Guide\n\nLocal services and opening hours.\n","solutionCode":"git commit -m \"Prepare neighborhood guide handoff\"\ngit log --oneline\ngit show --stat --oneline HEAD\ngit status --short","instructions":"Record the prepared maintenance snapshot with the message `Prepare neighborhood guide handoff`. Then inspect concise history, the newest commit summary, and final short status. The capstone should end with four focused commits and no unfinished tracked work.","starterFiles":{"zoeskoul_setup_sh":{"content":"$8b"}},"solutionFiles":{"zoeskoul_setup_sh":{"content":"$8c"}},"terminalExpectations":{"forbiddenCommands":{"0":{"message":"That action can discard or rewrite history. Use the safe, layer-specific workflow taught in this course."}},"requiredCommands":{"0":{"message":"Did you record the final maintenance snapshot?"},"1":{"message":"Did you inspect the four-entry history?"},"2":{"message":"Did you inspect the latest snapshot summary?"},"3":{"message":"Did you verify the clean final state?"}}}}},"description":"The capstone starts in `neighborhood-guide/` with no history from the other projects. File edits are still supplied exactly because this is a Git assessment. Your responsibility is to apply initialization, focused history, path maintenance, ignore rules, safe restore, and final verification across six cumulative steps.","title":"Complete the Neighborhood Guide Capstone"}}}},"linear-algebra":{"linear-algebra-0":{"vectors":{"label":"Vectors: meaning, dimension, and basic operations","summary":"Start with what a vector really is, how dimension works, and how to add or scale vectors.","cards":{"sketch":{"title":"Vectors as packets of information"},"quiz":{"title":"Quick check: vectors"}}},"numpy":{"label":"NumPy shapes: 1D, row, column, broadcasting","summary":"Learn the difference between mathematical dimension and NumPy shape so your code behaves the way you expect.","cards":{"sketch":{"title":"Why shape matters in Python"},"quiz":{"title":"Quick check: NumPy vectors"}}},"dot":{"label":"Dot product: one number that measures alignment","summary":"Compute dot products and connect the sign of the result to geometry and angle.","cards":{"sketch":{"title":"Dot product as alignment"},"quiz":{"title":"Quick check: dot product"}}},"products":{"label":"Hadamard vs outer product","summary":"Separate element-wise multiplication from matrix-building multiplication.","cards":{"sketch":{"title":"Two very different products"},"quiz":{"title":"Quick check: products"}}},"projection":{"label":"Projection: the part that points along a direction","summary":"Use projection to isolate the along-the-line part of a vector and separate it from the perpendicular part.","cards":{"sketch":{"title":"Projection as a shadow"},"quiz":{"title":"Quick check: projection"}}}},"linear-algebra-2":{"vector_spaces":{"label":"Vector spaces: the rules that make linear algebra work","summary":"Learn the axioms behind vector spaces and why closure, the zero vector, and scalar multiplication matter.","cards":{"sketch":{"title":"What makes a set a vector space?"},"quiz":{"title":"Quick check: vector spaces"}}},"subspaces":{"label":"Subspaces: smaller spaces living inside bigger ones","summary":"Understand when a subset of a vector space inherits the same structure and becomes a subspace.","cards":{"sketch":{"title":"Subspaces inside larger spaces"},"quiz":{"title":"Quick check: subspaces"}}},"linear_combinations":{"label":"Linear combinations and span","summary":"Build new vectors from old ones and understand how span describes everything you can reach.","cards":{"sketch":{"title":"Building vectors from ingredients"},"quiz":{"title":"Quick check: linear combinations"}}},"linear_independence":{"label":"Linear independence","summary":"Learn when vectors carry genuinely new information and when one vector is redundant.","cards":{"sketch":{"title":"Redundancy vs independence"},"quiz":{"title":"Quick check: linear independence"}}},"basis_dimension":{"label":"Basis and dimension","summary":"See how independence and span combine into basis, and how dimension measures the size of a space.","cards":{"sketch":{"title":"The minimal building blocks of a space"},"quiz":{"title":"Quick check: basis and dimension"}}},"transpose":{"label":"Transpose","summary":"Understand transpose as flipping rows and columns and learn the main algebra rules it obeys.","cards":{"sketch":{"title":"Flipping rows into columns"},"quiz":{"title":"Quick check: transpose"}}},"determinant":{"label":"Determinant","summary":"Compute determinants and connect them to area scaling, orientation, and invertibility.","cards":{"sketch":{"title":"Determinant as scaling and orientation"},"quiz":{"title":"Quick check: determinant"}}},"inverse":{"label":"Inverse","summary":"Learn what an inverse matrix does, when it exists, and how it undoes a transformation.","cards":{"sketch":{"title":"Undoing a linear transformation"},"quiz":{"title":"Quick check: inverse"}}},"eigenvalues_eigenvectors":{"label":"Eigenvalues and eigenvectors","summary":"Study the special directions a matrix only stretches or flips, and the scaling factors attached to them.","cards":{"sketch":{"title":"Special directions that keep their line"},"quiz":{"title":"Quick check: eigenvalues and eigenvectors"}}}}},"linux-terminal-fundamentals":{"linux-module-1-terminal-navigation":{"module-1-terminal-map-project":{"label":"Navigation Checkpoint: Campus Folder Tour","summary":"Use pwd, ls, and cd to inspect a prepared folder tree without changing it.","cards":{"sketch0":{"title":"Campus folder tour"},"project":{"title":"Project steps"}},"moduleProject":{"steps":{"module-1-terminal-map-project-terminal-task-1":{"title":"Milestone 1: Find the Club Hub","prompt":"Start by inspecting the workspace. Enter `club-hub` and confirm that it is now your current folder.","hint":"Inspect before moving, then verify the destination after the directory change.","help":{"concept":"The project begins by establishing the root of the prepared club workspace.","hint_1":"The destination folder is named `club-hub`.","hint_2":"Confirm the final working directory."},"starterCode":"# Build the terminal-map command sequence below.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `ls` to inspect the starting folder."},"1":{"message":"Enter `club-hub` with `cd club-hub`."},"2":{"message":"Use `pwd` to confirm where you are."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"club_hub_newsletter_draft_txt":{"content":"Newsletter draft\n"},"club_hub_events_checklist_txt":{"content":"Event checklist\n"},"club_hub_archive_old_note_txt":{"content":"Old note\n"},"main_sh":{"content":"# Build the terminal-map command sequence below.\n"}},"solutionCode":"ls\ncd club-hub\npwd\n","solutionFiles":{"main_sh":{"content":"ls\ncd club-hub\npwd\n"},"club_hub_newsletter_draft_txt":{"content":"Newsletter draft\n"},"club_hub_events_checklist_txt":{"content":"Event checklist\n"},"club_hub_archive_old_note_txt":{"content":"Old note\n"}}},"module-1-terminal-map-project-terminal-task-2":{"title":"Milestone 2: Inspect Newsletter and Return","prompt":"Visit the `newsletter` folder inside `club-hub`, inspect its contents, then return to `club-hub`.","hint":"Add only the navigation needed for this new stop; preserve the earlier project commands.","help":{"concept":"A cumulative terminal workflow can extend an earlier command sequence without replacing it.","hint_1":"Enter the newsletter folder and inspect it.","hint_2":"Finish back in the club hub."},"starterCode":"ls\ncd club-hub\npwd\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Enter the newsletter folder."},"1":{"message":"Use `cd ..` to go back up."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"club_hub_newsletter_draft_txt":{"content":"Newsletter draft\n"},"club_hub_events_checklist_txt":{"content":"Event checklist\n"},"club_hub_archive_old_note_txt":{"content":"Old note\n"},"main_sh":{"content":"ls\ncd club-hub\npwd\n"}},"solutionCode":"ls\ncd club-hub\npwd\ncd newsletter\nls\ncd ..\n","solutionFiles":{"main_sh":{"content":"ls\ncd club-hub\npwd\ncd newsletter\nls\ncd ..\n"},"club_hub_newsletter_draft_txt":{"content":"Newsletter draft\n"},"club_hub_events_checklist_txt":{"content":"Event checklist\n"},"club_hub_archive_old_note_txt":{"content":"Old note\n"}}},"module-1-terminal-map-project-terminal-task-3":{"title":"Milestone 3: Finish in Events","prompt":"Finish the handoff in the `events` folder. Move there from `club-hub`, confirm the final location, and inspect its contents so the next teammate can verify where you ended.","hint":"Preserve the first two milestones and add only the final trip into events.","help":{"concept":"The final project state is the complete navigation sequence ending in the requested destination.","hint_1":"The final directory must be `club-hub/events`.","hint_2":"Confirm the path and inspect the destination."},"starterCode":"ls\ncd club-hub\npwd\ncd newsletter\nls\ncd ..\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Move into the events folder."},"1":{"message":"Use `pwd` before finishing."},"2":{"message":"List the final folder."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"club_hub_newsletter_draft_txt":{"content":"Newsletter draft\n"},"club_hub_events_checklist_txt":{"content":"Event checklist\n"},"club_hub_archive_old_note_txt":{"content":"Old note\n"},"main_sh":{"content":"ls\ncd club-hub\npwd\ncd newsletter\nls\ncd ..\n"}},"solutionCode":"ls\ncd club-hub\npwd\ncd newsletter\nls\ncd ..\ncd events\npwd\nls\n","solutionFiles":{"main_sh":{"content":"ls\ncd club-hub\npwd\ncd newsletter\nls\ncd ..\ncd events\npwd\nls\n"},"club_hub_newsletter_draft_txt":{"content":"Newsletter draft\n"},"club_hub_events_checklist_txt":{"content":"Event checklist\n"},"club_hub_archive_old_note_txt":{"content":"Old note\n"}}}}}},"moving-around":{"label":"Moving Around with cd","summary":"Move between folders with cd, cd .., and simple relative paths.","cards":{"sketch0":{"title":"Use `cd` to enter a folder"},"sketch1":{"title":"Use `cd ..` to go up one folder"},"sketch2":{"title":"Use simple relative paths"},"quiz":{"title":"Practice check"}},"practice":{"sc-cd-purpose":{"title":"What `cd` does","prompt":"What does `cd` do?","hint":"Confirm the starting location with `pwd`, then follow the folder names in order.","help":{"concept":"`cd` changes the current directory; `..` means one parent level and a relative path begins from the current directory.","hint_1":"Confirm the starting location with `pwd`, then follow the folder names in order.","hint_2":"Run `pwd` or `ls` after moving so the destination is proven rather than assumed. The current task asks: What does `cd` do?"},"options":{"a":"Changes the current folder","b":"Copies a file","c":"Deletes a file","d":"Prints file content"}},"sc-parent-folder":{"title":"Meaning of `..`","prompt":"In a path, what does `..` mean?","hint":"Confirm the starting location with `pwd`, then follow the folder names in order.","help":{"concept":"`cd` changes the current directory; `..` means one parent level and a relative path begins from the current directory.","hint_1":"Confirm the starting location with `pwd`, then follow the folder names in order.","hint_2":"Run `pwd` or `ls` after moving so the destination is proven rather than assumed. The current task asks: In a path, what does `..` mean?"},"options":{"a":"The parent folder","b":"A hidden file","c":"The current file","d":"The root password"}},"mc-check-after-cd":{"title":"Verify a navigation result","prompt":"Which commands can help verify a navigation result after `cd`?","hint":"Think about confirming both the destination path and what is present there.","help":{"concept":"`pwd` confirms the current path. `ls` can help confirm that the expected destination contents are present.","hint_1":"One command reports the path itself.","hint_2":"Another inspects the destination contents."},"options":{"a":"pwd","b":"ls","c":"rm","d":"sudo"}},"dr-navigate-and-check":{"title":"Move and confirm","prompt":"Put the navigation routine in order.","hint":"Confirm the starting location with `pwd`, then follow the folder names in order.","help":{"concept":"`cd` changes the current directory; `..` means one parent level and a relative path begins from the current directory.","hint_1":"Confirm the starting location with `pwd`, then follow the folder names in order.","hint_2":"Run `pwd` or `ls` after moving so the destination is proven rather than assumed. The current task asks: Put the navigation routine in order."},"tokens":{"t1":"Type `ls` to find a folder","t2":"Type `cd folder-name`","t3":"Type `pwd` or `ls` to confirm"}}},"tryIt":{"allowReveal":true,"exercises":{"moving-around-try-it-1":{"title":"Try It: Enter the Newsletter Folder","prompt":"The `newsletter` folder is inside your current directory. Use `cd newsletter`, then run `pwd` to confirm where you landed.","hint":"This guided example changes the working directory and then checks the result.","help":{"concept":"Changing directory updates the terminal's current location.","hint_1":"Enter the child folder first.","hint_2":"Then print the working directory."},"starterCode":"# Move into the guided newsletter destination.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `cd newsletter` to enter the folder."},"1":{"message":"Use `pwd` to confirm where you landed."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"newsletter_brief_txt":{"content":"Community newsletter brief\n"},"main_sh":{"content":"# Move into the guided newsletter destination.\n"}},"solutionCode":"cd newsletter\npwd\n","solutionFiles":{"main_sh":{"content":"cd newsletter\npwd\n"},"newsletter_brief_txt":{"content":"Community newsletter brief\n"}}},"moving-around-try-it-2":{"title":"Practice: Return to the Parent Folder","prompt":"Move up one folder from your current location, then confirm the new working directory.","hint":"Use the special relative-path marker for the parent directory.","help":{"concept":"The parent directory is one level above the current folder.","hint_1":"Move upward only one level.","hint_2":"Verify where you ended."},"starterCode":"# Return one folder level and verify the result.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `cd ..` to go up one folder."},"1":{"message":"Use `pwd` to confirm the library-kit folder."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"library_kit_returns_today_txt":{"content":"Three books returned\n"},"main_sh":{"content":"# Return one folder level and verify the result.\n"}},"solutionCode":"cd ..\npwd\n","solutionFiles":{"main_sh":{"content":"cd ..\npwd\n"},"library_kit_returns_today_txt":{"content":"Three books returned\n"}}},"moving-around-try-it-3":{"title":"Practice: Follow a Relative Path","prompt":"Starting from the museum tour workspace, reach the `signs` folder using a relative path and inspect what is inside.","hint":"A relative path can cross both folder names in a single navigation step.","help":{"concept":"Relative paths are interpreted from the terminal's current working directory.","hint_1":"Use both folder names in the path.","hint_2":"Inspect the destination after you arrive."},"starterCode":"# Navigate to the requested relative destination.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `cd museum-tour/signs` to enter the nested folder."},"1":{"message":"Use `ls` to inspect the signs folder."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"museum_tour_signs_labels_txt":{"content":"Entrance\nExit\n"},"main_sh":{"content":"# Navigate to the requested relative destination.\n"}},"solutionCode":"cd museum-tour/signs\nls\n","solutionFiles":{"main_sh":{"content":"cd museum-tour/signs\nls\n"},"museum_tour_signs_labels_txt":{"content":"Entrance\nExit\n"}}}},"try_moving_around_sketch0":{"title":"Enter the newsletter folder","prompt":"Move into `newsletter` and confirm. Press **Enter** after each command."},"try_moving_around_sketch1":{"title":"Return from the returns folder","prompt":"Move up from `returns` to `library-kit`. Press **Enter** after each command."},"try_moving_around_sketch2":{"title":"Reach the museum signs folder","prompt":"Use one relative path to reach the signs. Press **Enter** after each command."}}},"what-the-terminal-is":{"label":"What the Terminal Is","summary":"Meet the terminal as a calm place to type commands, read output, and check before changing anything.","cards":{"course-introduction":{"title":"Course introduction"},"sketch0":{"title":"The terminal is a command conversation"},"sketch1":{"title":"Prompt, command, and output"},"sketch2":{"title":"Start with safe inspection"},"quiz":{"title":"Practice check"}},"practice":{"sc-terminal-output":{"title":"What output means","prompt":"In the terminal, what is output?","hint":"Separate the prompt from the command and read the response before continuing.","help":{"concept":"The terminal follows a command → output → verification cycle.","hint_1":"Separate the prompt from the command and read the response before continuing.","hint_2":"Use the requested safe inspection command and compare its output with the exact task. The current task asks: In the terminal, what is output?"},"options":{"a":"The text the terminal prints after a command","b":"A folder that stores commands","c":"A file that must be deleted","d":"The name of the mouse pointer"}},"mc-safe-inspection":{"title":"Run a terminal command","prompt":"Which actions are part of correctly running a simple terminal command?","hint":"Think about what happens after the prompt appears and before you receive output.","help":{"concept":"A basic interaction is: type a command, submit it, then read the terminal's result.","hint_1":"The prompt itself is not part of the command.","hint_2":"The command must be submitted before output appears."},"options":{"a":"Type the command at the prompt","b":"Press Enter to run the command","c":"Assume it worked without reading the result","d":"Copy the prompt symbols into the command"}},"dr-terminal-flow":{"title":"Order a terminal interaction","prompt":"Put the parts of a simple terminal interaction in order.","hint":"Separate the prompt from the command and read the response before continuing.","help":{"concept":"The terminal follows a command → output → verification cycle.","hint_1":"Separate the prompt from the command and read the response before continuing.","hint_2":"Use the requested safe inspection command and compare its output with the exact task. The current task asks: Put the parts of a simple terminal interaction in order."},"tokens":{"t1":"The prompt appears","t2":"You type a command","t3":"You press Enter","t4":"You read the output"}},"sc-before-changing":{"title":"Before changing files","prompt":"What is the best first move in a new workspace?","hint":"Separate the prompt from the command and read the response before continuing.","help":{"concept":"The terminal follows a command → output → verification cycle.","hint_1":"Separate the prompt from the command and read the response before continuing.","hint_2":"Use the requested safe inspection command and compare its output with the exact task. The current task asks: What is the best first move in a new workspace?"},"options":{"a":"Inspect where you are and what is nearby","b":"Delete temporary-looking files immediately","c":"Move every file into one folder","d":"Use sudo just in case"}}},"tryIt":{"allowReveal":true,"exercises":{"what-terminal-is-try-it-1":{"title":"Try It: Find Your Current Location","prompt":"You are starting at the welcome desk. Run `pwd` to see the full path of the folder the terminal opened in.","hint":"This is a guided first command. Read the path the terminal prints before continuing.","help":{"concept":"The shell always has a current working directory.","hint_1":"Use the command that prints the working directory.","hint_2":"The answer appears in the terminal output."},"starterCode":"# Run the guided orientation command in the terminal.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Type `pwd` to print the current folder."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"welcome_desk_shift_note_txt":{"content":"Morning volunteer shift\n"},"main_sh":{"content":"# Run the guided orientation command in the terminal.\n"}},"solutionCode":"pwd\n","solutionFiles":{"main_sh":{"content":"pwd\n"},"welcome_desk_shift_note_txt":{"content":"Morning volunteer shift\n"}}},"what-terminal-is-try-it-2":{"title":"Practice: Inspect the Supply Room","prompt":"Take a quick look around the supply room. Find out which files and folders are already there without changing anything.","hint":"Use the read-only command that lists the current directory.","help":{"concept":"Inspecting a directory is different from changing it.","hint_1":"You only need to see the names already present.","hint_2":"Do not move or modify anything."},"starterCode":"# Inspect the current workspace without changing it.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Type `ls` to list the supply room."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"supply_room_labels_txt":{"content":"Name tags\n"},"supply_room_inventory_txt":{"content":"Markers\nTape\n"},"main_sh":{"content":"# Inspect the current workspace without changing it.\n"}},"solutionCode":"ls\n","solutionFiles":{"main_sh":{"content":"ls\n"},"supply_room_labels_txt":{"content":"Name tags\n"},"supply_room_inventory_txt":{"content":"Markers\nTape\n"}}},"what-terminal-is-try-it-3":{"title":"Use the first safe check","prompt":"A teammate left you at the check-in desk. Type `pwd`, then `ls`, before deciding what to do next. Press **Enter** after each command and wait for its result before typing the next one.","hint":"Separate the prompt from the command and read the response before continuing.","help":{"concept":"The terminal follows a command → output → verification cycle.","hint_1":"Separate the prompt from the command and read the response before continuing.","hint_2":"Use the requested safe inspection command and compare its output with the exact task. The current task asks: A teammate left you at the check-in desk. Type `pwd`, then `ls`, before deciding what to do next."},"starterCode":"# Use the terminal for this task.","terminalExpectations":{"requiredCommands":{"0":{"message":"Type `pwd` first to confirm your location."},"1":{"message":"Type `ls` to inspect the current folder."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"check_in_arrival_note_txt":{"content":"Open doors at 8:00\n"}}}},"try_what_the_terminal_is_sketch0":{"title":"Identify the welcome desk folder","prompt":"Ask the terminal where the welcome desk is. Press **Enter** to run the command."},"try_what_the_terminal_is_sketch1":{"title":"Inspect the supply room","prompt":"List what is stored in the supply room. Press **Enter** to run the command."},"try_what_the_terminal_is_sketch2":{"title":"Use the first safe check","prompt":"Confirm your location, then inspect it. Press **Enter** after each command."}}},"where-am-i":{"label":"Where Am I? pwd and ls","summary":"Use pwd and ls together to understand your current location before touching files.","cards":{"sketch0":{"title":"`pwd` shows your current folder"},"sketch1":{"title":"`ls` shows what is nearby"},"sketch2":{"title":"Use `pwd` and `ls` as a pair"},"quiz":{"title":"Practice check"}},"practice":{"sc-pwd-purpose":{"title":"What `pwd` tells you","prompt":"Which command shows the full path to your current folder?","hint":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","help":{"concept":"`pwd` confirms the current directory and `ls` reports the names inside it.","hint_1":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","hint_2":"Do not create or move files in an inspection task; verify location and names only. The current task asks: Which command shows the full path to your current folder?"},"options":{"a":"pwd","b":"ls","c":"cd","d":"touch"}},"sc-ls-purpose":{"title":"What `ls` shows","prompt":"Which command lists the files and folders in the current folder?","hint":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","help":{"concept":"`pwd` confirms the current directory and `ls` reports the names inside it.","hint_1":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","hint_2":"Do not create or move files in an inspection task; verify location and names only. The current task asks: Which command lists the files and folders in the current folder?"},"options":{"a":"pwd","b":"mkdir","c":"ls","d":"rm"}},"mc-inspection-commands":{"title":"Commands that only inspect","prompt":"Choose the commands that inspect without creating, moving, or removing files.","hint":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","help":{"concept":"`pwd` confirms the current directory and `ls` reports the names inside it.","hint_1":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","hint_2":"Do not create or move files in an inspection task; verify location and names only. The current task asks: Choose the commands that inspect without creating, moving, or removing files."},"options":{"a":"pwd","b":"ls","c":"mv","d":"rm"}},"dr-safe-check-order":{"title":"Orient before choosing an action","prompt":"Put this safe orientation routine in order.","hint":"Establish location first, inspect the folder second, then decide what should happen next.","help":{"concept":"Orientation establishes context before a modifying command is chosen.","hint_1":"First determine the working directory.","hint_2":"Then inspect its contents before deciding what to do."},"tokens":{"t1":"Run `pwd` to confirm the current location","t2":"Run `ls` to inspect the current folder","t3":"Read both results before choosing the next action"}}},"tryIt":{"allowReveal":true,"exercises":{"where-am-i-try-it-1":{"title":"Try It: Confirm the Newsroom Path","prompt":"Before you do anything else in this workspace, run `pwd` and use the output to identify your current folder.","hint":"Use the command that prints the current working directory.","help":{"concept":"The current path tells you where relative paths will begin.","hint_1":"You do not need to move anywhere.","hint_2":"Read the full path from the terminal result."},"starterCode":"# Confirm the current newsroom location.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `pwd` to print the newsroom path."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"newsroom_assignment_txt":{"content":"Draft the Saturday update\n"},"main_sh":{"content":"# Confirm the current newsroom location.\n"}},"solutionCode":"pwd\n","solutionFiles":{"main_sh":{"content":"pwd\n"},"newsroom_assignment_txt":{"content":"Draft the Saturday update\n"}}},"where-am-i-try-it-2":{"title":"Practice: Inspect the Art Table","prompt":"Check what files and folders are in your current location. This is an inspection task, so leave the workspace unchanged.","hint":"Use the directory-inspection command you practiced earlier.","help":{"concept":"Listing a directory lets you verify what is available before you reference a file by name.","hint_1":"Stay in the current folder.","hint_2":"Only inspect its contents."},"starterCode":"# Inspect the current art-table folder.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `ls` to list the art table."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"art_table_brushes_txt":{"content":"Small brush\nLarge brush\n"},"art_table_paint_list_txt":{"content":"Blue\nYellow\n"},"main_sh":{"content":"# Inspect the current art-table folder.\n"}},"solutionCode":"ls\n","solutionFiles":{"main_sh":{"content":"ls\n"},"art_table_brushes_txt":{"content":"Small brush\nLarge brush\n"},"art_table_paint_list_txt":{"content":"Blue\nYellow\n"}}},"where-am-i-try-it-3":{"title":"Orient yourself at the event desk","prompt":"Before touching the event desk files, type `pwd` and then `ls`. Read both results. Press **Enter** after each command and wait for its result before typing the next one.","hint":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","help":{"concept":"`pwd` confirms the current directory and `ls` reports the names inside it.","hint_1":"Run `pwd` before interpreting a relative path, then use `ls` on the folder named in the task.","hint_2":"Do not create or move files in an inspection task; verify location and names only. The current task asks: Before touching the event desk files, type `pwd` and then `ls`. Read both results."},"starterCode":"# Use the terminal for this task.","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `pwd` to confirm the event desk path."},"1":{"message":"Use `ls` to inspect the event desk."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"event_desk_run_sheet_txt":{"content":"Doors open at 6:00\n"},"event_desk_contact_txt":{"content":"Call the coordinator\n"}}}},"try_where_am_i_sketch0":{"title":"Confirm the newsroom location","prompt":"Print the newsroom path. Press **Enter** to run the command."},"try_where_am_i_sketch1":{"title":"See what is on the art table","prompt":"List the art table files. Press **Enter** to run the command."},"try_where_am_i_sketch2":{"title":"Orient yourself at the event desk","prompt":"Check the event desk before editing. Press **Enter** after each command."}}}},"linux-module-2-files-and-folders":{"copy-move-rename":{"label":"Copy, Move, and Rename","summary":"Use cp and mv to prepare a clean handoff without losing the original when a backup matters.","cards":{"sketch0":{"title":"Use `cp` when you need a backup"},"sketch1":{"title":"Use `mv` to move a file"},"sketch2":{"title":"Use `mv` to rename a file"},"quiz":{"title":"Practice check"}},"practice":{"sc-copy-keeps-original":{"title":"Copy without removing original","prompt":"Which command copies `a.txt` to `b.txt` and keeps `a.txt`?","hint":"Read the source and destination paths from left to right before running the command.","help":{"concept":"`cp` preserves the source by creating a copy; `mv` relocates or renames the source.","hint_1":"Read the source and destination paths from left to right before running the command.","hint_2":"Verify both locations: a copy leaves both files, while a move or rename removes the old path. The current task asks: Which command copies `a.txt` to `b.txt` and keeps `a.txt`?"},"options":{"a":"cp a.txt b.txt","b":"mv a.txt b.txt","c":"rm a.txt","d":"cd a.txt"}},"sc-move-command":{"title":"Move into a folder","prompt":"Which command moves `note.txt` into `handoff/note.txt`?","hint":"Read the source and destination paths from left to right before running the command.","help":{"concept":"`cp` preserves the source by creating a copy; `mv` relocates or renames the source.","hint_1":"Read the source and destination paths from left to right before running the command.","hint_2":"Verify both locations: a copy leaves both files, while a move or rename removes the old path. The current task asks: Which command moves `note.txt` into `handoff/note.txt`?"},"options":{"a":"mv note.txt handoff/note.txt","b":"cp note.txt","c":"cat handoff/note.txt","d":"pwd note.txt"}},"mc-mv-uses":{"title":"Two uses of `mv`","prompt":"What can `mv` do in this course?","hint":"Read the source and destination paths from left to right before running the command.","help":{"concept":"`cp` preserves the source by creating a copy; `mv` relocates or renames the source.","hint_1":"Read the source and destination paths from left to right before running the command.","hint_2":"Verify both locations: a copy leaves both files, while a move or rename removes the old path. The current task asks: What can `mv` do in this course?"},"options":{"a":"Move a file into another folder","b":"Rename a file","c":"Count lines","d":"Print the current folder"}},"dr-backup-then-move":{"title":"Required backup before handoff","prompt":"A handoff requires a backup copy before the working file is moved. Put the required steps in order.","hint":"Preserve the backup first, perform the move second, then verify.","help":{"concept":"`cp` preserves the source by creating a copy; `mv` relocates or renames the source.","hint_1":"Read the source and destination paths from left to right before running the command.","hint_2":"Verify both locations: a copy leaves both files, while a move or rename removes the old path. The current task asks: Put these handoff steps in a safe order."},"tokens":{"t1":"Create the required backup copy","t2":"Move the working file into handoff","t3":"List the destination to verify"}}},"tryIt":{"allowReveal":true,"exercises":{"copy-move-rename-try-it-1":{"title":"Try It: Back Up the Attendee List","prompt":"Use `cp` to make `attendee-list-backup.txt` from `attendee-list.txt`. Keep the original file in place and list the folder afterward to verify the backup.","hint":"The original attendee list must remain in place.","help":{"concept":"`cp` preserves the source; `mv` relocates or renames it.","hint_1":"Read source and destination paths from left to right.","hint_2":"Verify both the old and new locations after the operation."},"starterCode":"# Create the guided backup and verify it.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `cp` to create the attendee list backup."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"registration_attendee_list_txt":{"content":"Amina\nDiego\nMaya\n"},"main_sh":{"content":"# Create the guided backup and verify it.\n"}},"solutionCode":"cp attendee-list.txt attendee-list-backup.txt\nls\n","solutionFiles":{"main_sh":{"content":"cp attendee-list.txt attendee-list-backup.txt\nls\n"},"registration_attendee_list_txt":{"content":"Amina\nDiego\nMaya\n"},"registration_attendee_list_backup_txt":{"content":"Amina\nDiego\nMaya\n"}}},"copy-move-rename-try-it-2":{"title":"Practice: Move the Banner Note","prompt":"The banner note is ready for handoff. Move `banner-note.txt` into the `handoff` folder so it ends up at `handoff/banner-note.txt`, then verify the destination.","hint":"Use the file operation that relocates rather than duplicates.","help":{"concept":"`cp` preserves the source; `mv` relocates or renames it.","hint_1":"Read source and destination paths from left to right.","hint_2":"Verify both the old and new locations after the operation."},"starterCode":"# Relocate the banner note and verify the destination.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mv` to place the banner note in handoff."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"sign_shop_banner_note_txt":{"content":"Hang the welcome banner by 8:30.\n"},"sign_shop_handoff_keep":{"content":""},"main_sh":{"content":"# Relocate the banner note and verify the destination.\n"},"sign_shop_handoff__keep":{"content":""}},"solutionCode":"mv banner-note.txt handoff/banner-note.txt\nls handoff\n","solutionFiles":{"main_sh":{"content":"mv banner-note.txt handoff/banner-note.txt\nls handoff\n"},"sign_shop_handoff__keep":{"content":""},"sign_shop_handoff_banner_note_txt":{"content":"Hang the welcome banner by 8:30.\n"}}},"copy-move-rename-try-it-3":{"title":"Practice: Rename the Approved Schedule","prompt":"The schedule has been approved. Rename `schedule-draft.txt` to `schedule-final.txt` in the same folder, then verify that the final name is present.","hint":"A rename uses the same operation as a move.","help":{"concept":"`cp` preserves the source; `mv` relocates or renames it.","hint_1":"Read source and destination paths from left to right.","hint_2":"Verify both the old and new locations after the operation."},"starterCode":"# Rename the approved schedule and verify it.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mv` to rename the approved schedule."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"schedule_desk_schedule_draft_txt":{"content":"Opening: 9:00\nWorkshop: 10:30\n"},"main_sh":{"content":"# Rename the approved schedule and verify it.\n"}},"solutionCode":"mv schedule-draft.txt schedule-final.txt\nls\n","solutionFiles":{"main_sh":{"content":"mv schedule-draft.txt schedule-final.txt\nls\n"},"schedule_desk_schedule_final_txt":{"content":"Opening: 9:00\nWorkshop: 10:30\n"}}}},"try_copy_move_rename_sketch0":{"title":"Back up the attendee list","prompt":"Copy a different important file. Press **Enter** after each command."},"try_copy_move_rename_sketch1":{"title":"Move a banner note to handoff","prompt":"Move a different file into handoff. Press **Enter** after each command."},"try_copy_move_rename_sketch2":{"title":"Rename the approved schedule","prompt":"Rename a different approved draft. Press **Enter** after each command."}}},"creating-folders-and-files":{"label":"Creating Folders and Files","summary":"Create useful folder structures with mkdir, mkdir -p, and touch.","cards":{"sketch0":{"title":"Create one folder with `mkdir`"},"sketch1":{"title":"Create nested folders with `mkdir -p`"},"sketch2":{"title":"Create empty files with `touch`"},"quiz":{"title":"Practice check"}},"practice":{"sc-mkdir-purpose":{"title":"What `mkdir` creates","prompt":"What does `mkdir` create?","hint":"Create parent folders before files and copy every required path exactly.","help":{"concept":"`mkdir` creates folders, `mkdir -p` creates missing parent paths, and `touch` creates an empty file.","hint_1":"Create parent folders before files and copy every required path exactly.","hint_2":"Use targeted `ls` commands to verify each new folder or file before checking the answer. The current task asks: What does `mkdir` create?"},"options":{"a":"A folder","b":"A printed file preview","c":"A deleted file","d":"A password"}},"mc-mkdir-p-use":{"title":"When `mkdir -p` helps","prompt":"When is `mkdir -p` useful?","hint":"Create parent folders before files and copy every required path exactly.","help":{"concept":"`mkdir` creates folders, `mkdir -p` creates missing parent paths, and `touch` creates an empty file.","hint_1":"Create parent folders before files and copy every required path exactly.","hint_2":"Use targeted `ls` commands to verify each new folder or file before checking the answer. The current task asks: When is `mkdir -p` useful?"},"options":{"a":"When parent folders may not exist yet","b":"When creating nested folders","c":"When deleting a file","d":"When printing file text"}},"sc-touch-purpose":{"title":"What `touch` creates","prompt":"What does `touch notes.txt` do if `notes.txt` does not exist?","hint":"Create parent folders before files and copy every required path exactly.","help":{"concept":"`mkdir` creates folders, `mkdir -p` creates missing parent paths, and `touch` creates an empty file.","hint_1":"Create parent folders before files and copy every required path exactly.","hint_2":"Use targeted `ls` commands to verify each new folder or file before checking the answer. The current task asks: What does `touch notes.txt` do if `notes.txt` does not exist?"},"options":{"a":"Creates an empty file","b":"Prints the file","c":"Moves the file","d":"Deletes the file"}},"dr-folder-before-file":{"title":"Folders before files","prompt":"Put the setup steps in a safe order.","hint":"Create parent folders before files and copy every required path exactly.","help":{"concept":"`mkdir` creates folders, `mkdir -p` creates missing parent paths, and `touch` creates an empty file.","hint_1":"Create parent folders before files and copy every required path exactly.","hint_2":"Use targeted `ls` commands to verify each new folder or file before checking the answer. The current task asks: Put the setup steps in a safe order."},"tokens":{"t1":"Create the parent folder","t2":"Create files inside it","t3":"List the folder to check"}}},"tryIt":{"allowReveal":true,"exercises":{"creating-folders-and-files-try-it-1":{"title":"Try It: Create One Folder","prompt":"Create a folder named `volunteer-desk` with `mkdir`, then list the current directory to make sure the new folder is there.","hint":"This guided task uses the basic directory-creation command.","help":{"concept":"`mkdir` creates directories and `touch` can create empty files.","hint_1":"Build parent directories before relying on paths inside them.","hint_2":"Verify the resulting filesystem rather than assuming the command worked."},"starterCode":"# Create the requested directory and verify it.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mkdir` to create the volunteer desk folder."},"1":{"message":"Use `ls` to confirm the folder exists."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"solutionCode":"mkdir volunteer-desk\nls\n","starterFiles":{"main_sh":{"content":"# Create the requested directory and verify it.\n"}},"solutionFiles":{"main_sh":{"content":"mkdir volunteer-desk\nls\n"}}},"creating-folders-and-files-try-it-2":{"title":"Practice: Build a Nested Event Pack","prompt":"Set up `event-pack/signs` and `event-pack/schedules`. The parent folder does not exist yet, so choose a directory-creation approach that can build the full structure, then verify it.","hint":"Choose a directory-creation approach that can handle missing parent folders.","help":{"concept":"`mkdir` creates directories and `touch` can create empty files.","hint_1":"Build parent directories before relying on paths inside them.","hint_2":"Verify the resulting filesystem rather than assuming the command worked."},"starterCode":"# Build the requested nested directory structure.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mkdir` or `mkdir -p` to build the folders."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"solutionCode":"mkdir -p event-pack/signs\nmkdir -p event-pack/schedules\nls event-pack\n","starterFiles":{"main_sh":{"content":"# Build the requested nested directory structure.\n"}},"solutionFiles":{"main_sh":{"content":"mkdir -p event-pack/signs\nmkdir -p event-pack/schedules\nls event-pack\n"}}},"creating-folders-and-files-try-it-3":{"title":"Practice: Add Planning Files","prompt":"You are already inside `planning-board`. Add empty `tasks.txt` and `contacts.txt` files, then check the folder to make sure both were created.","hint":"Use the command for creating empty placeholder files.","help":{"concept":"`mkdir` creates directories and `touch` can create empty files.","hint_1":"Build parent directories before relying on paths inside them.","hint_2":"Verify the resulting filesystem rather than assuming the command worked."},"starterCode":"# Add the two requested empty files.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `touch` to create the two planning files."},"1":{"message":"Use `ls` to confirm both files are present."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"planning_board_readme_txt":{"content":"Planning board workspace\n"},"main_sh":{"content":"# Add the two requested empty files.\n"},"planning_board_README_txt":{"content":"Planning board workspace\n"}},"solutionCode":"touch tasks.txt\ntouch contacts.txt\nls\n","solutionFiles":{"main_sh":{"content":"touch tasks.txt\ntouch contacts.txt\nls\n"},"planning_board_README_txt":{"content":"Planning board workspace\n"}}}},"try_creating_folders_and_files_sketch0":{"title":"Create a volunteer desk folder","prompt":"Create `volunteer-desk`. Press **Enter** after each command."},"try_creating_folders_and_files_sketch1":{"title":"Build an event pack","prompt":"Create two nested event folders. Press **Enter** after each command."},"try_creating_folders_and_files_sketch2":{"title":"Create planning board files","prompt":"Create two files inside `planning-board`. Press **Enter** after each command."}}},"module-2-notes-organizer-project":{"label":"Project: Class Notes Handoff","summary":"Build a notes workspace, write a handoff file, move notes, and remove only temporary scratch.","cards":{"sketch0":{"title":"Class notes handoff"},"project":{"title":"Project steps"}},"moduleProject":{"steps":{"module-2-notes-organizer-project-terminal-task-1":{"title":"Milestone 1: Complete the Organizer Structure","prompt":"The organizer inbox already contains `math.txt`, `history.txt`, and `tmp-scratch.txt`. Add the missing `handoff` and `archive` folders, then inspect the organizer to make sure the incoming notes are still untouched.","hint":"Preserve every incoming note. This milestone only completes the directory structure.","help":{"concept":"A cumulative workspace preserves the incoming notes while the organizer structure is completed.","hint_1":"The inbox already exists because it contains the incoming files.","hint_2":"Create only the missing organizer directories and verify them."},"starterCode":"# Complete the organizer around the existing inbox.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mkdir` or `mkdir -p` to create the workspace folders."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"solutionCode":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\n","starterFiles":{"main_sh":{"content":"# Complete the organizer around the existing inbox.\n"},"class_notes_organizer_inbox__keep":{"content":""},"class_notes_organizer_inbox_math_txt":{"content":"Math notes\n"},"class_notes_organizer_inbox_history_txt":{"content":"History notes\n"},"class_notes_organizer_inbox_tmp_scratch_txt":{"content":"scratch\n"}},"solutionFiles":{"main_sh":{"content":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\n"},"class_notes_organizer_inbox__keep":{"content":""},"class_notes_organizer_handoff__keep":{"content":""},"class_notes_organizer_archive__keep":{"content":""},"class_notes_organizer_inbox_math_txt":{"content":"Math notes\n"},"class_notes_organizer_inbox_history_txt":{"content":"History notes\n"},"class_notes_organizer_inbox_tmp_scratch_txt":{"content":"scratch\n"}}},"module-2-notes-organizer-project-terminal-task-2":{"title":"Milestone 2: Write the Handoff README","prompt":"Now create the handoff guide. Write `Substitute teacher handoff` as the first line of `class-notes-organizer/handoff/README.txt`, add `Bring math worksheets` as the second line, and read the file to check the result.","hint":"Preserve the completed folders and inbox notes while adding only the handoff documentation.","help":{"concept":"The second milestone adds handoff documentation without discarding the workspace created earlier.","hint_1":"The README needs two lines in the specified order.","hint_2":"Read the completed file after writing it."},"starterCode":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `echo` with `>` to write the first line."},"1":{"message":"Use `>>` to append the second line."},"2":{"message":"Read the handoff file with `cat`."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"solutionCode":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\necho \"Substitute teacher handoff\" > class-notes-organizer/handoff/README.txt\necho \"Bring math worksheets\" >> class-notes-organizer/handoff/README.txt\ncat class-notes-organizer/handoff/README.txt\n","starterFiles":{"main_sh":{"content":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\n"},"class_notes_organizer_inbox__keep":{"content":""},"class_notes_organizer_handoff__keep":{"content":""},"class_notes_organizer_archive__keep":{"content":""},"class_notes_organizer_inbox_math_txt":{"content":"Math notes\n"},"class_notes_organizer_inbox_history_txt":{"content":"History notes\n"},"class_notes_organizer_inbox_tmp_scratch_txt":{"content":"scratch\n"}},"solutionFiles":{"main_sh":{"content":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\necho \"Substitute teacher handoff\" > class-notes-organizer/handoff/README.txt\necho \"Bring math worksheets\" >> class-notes-organizer/handoff/README.txt\ncat class-notes-organizer/handoff/README.txt\n"},"class_notes_organizer_inbox__keep":{"content":""},"class_notes_organizer_handoff__keep":{"content":""},"class_notes_organizer_archive__keep":{"content":""},"class_notes_organizer_inbox_math_txt":{"content":"Math notes\n"},"class_notes_organizer_inbox_history_txt":{"content":"History notes\n"},"class_notes_organizer_inbox_tmp_scratch_txt":{"content":"scratch\n"},"class_notes_organizer_handoff_README_txt":{"content":"Substitute teacher handoff\nBring math worksheets\n"}}},"module-2-notes-organizer-project-terminal-task-3":{"title":"Milestone 3: Archive Notes and Remove Scratch","prompt":"Finish the organizer by moving `math.txt` and `history.txt` from the inbox into the archive. Delete only `tmp-scratch.txt`, then inspect the final folders and make sure the handoff README remains.","hint":"The real notes must survive in the archive; only the explicitly named scratch file should disappear.","help":{"concept":"The final milestone archives real notes and deletes only the confirmed temporary scratch file.","hint_1":"Both subject notes must end in the archive.","hint_2":"The README must remain and only the scratch file should vanish."},"starterCode":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\necho \"Substitute teacher handoff\" > class-notes-organizer/handoff/README.txt\necho \"Bring math worksheets\" >> class-notes-organizer/handoff/README.txt\ncat class-notes-organizer/handoff/README.txt\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mv` to move the notes into archive."},"1":{"message":"Remove only the temporary scratch file."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"class_notes_organizer_inbox_math_txt":{"content":"Math notes\n"},"class_notes_organizer_inbox_history_txt":{"content":"History notes\n"},"class_notes_organizer_inbox_tmp_scratch_txt":{"content":"scratch\n"},"main_sh":{"content":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\necho \"Substitute teacher handoff\" > class-notes-organizer/handoff/README.txt\necho \"Bring math worksheets\" >> class-notes-organizer/handoff/README.txt\ncat class-notes-organizer/handoff/README.txt\n"},"class_notes_organizer_inbox__keep":{"content":""},"class_notes_organizer_handoff__keep":{"content":""},"class_notes_organizer_archive__keep":{"content":""},"class_notes_organizer_handoff_README_txt":{"content":"Substitute teacher handoff\nBring math worksheets\n"}},"solutionCode":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\necho \"Substitute teacher handoff\" > class-notes-organizer/handoff/README.txt\necho \"Bring math worksheets\" >> class-notes-organizer/handoff/README.txt\ncat class-notes-organizer/handoff/README.txt\nmv class-notes-organizer/inbox/math.txt class-notes-organizer/archive/math.txt\nmv class-notes-organizer/inbox/history.txt class-notes-organizer/archive/history.txt\nrm class-notes-organizer/inbox/tmp-scratch.txt\nls class-notes-organizer/archive\nls class-notes-organizer/inbox\n","solutionFiles":{"main_sh":{"content":"mkdir -p class-notes-organizer/handoff\nmkdir -p class-notes-organizer/archive\nls class-notes-organizer\necho \"Substitute teacher handoff\" > class-notes-organizer/handoff/README.txt\necho \"Bring math worksheets\" >> class-notes-organizer/handoff/README.txt\ncat class-notes-organizer/handoff/README.txt\nmv class-notes-organizer/inbox/math.txt class-notes-organizer/archive/math.txt\nmv class-notes-organizer/inbox/history.txt class-notes-organizer/archive/history.txt\nrm class-notes-organizer/inbox/tmp-scratch.txt\nls class-notes-organizer/archive\nls class-notes-organizer/inbox\n"},"class_notes_organizer_inbox__keep":{"content":""},"class_notes_organizer_handoff__keep":{"content":""},"class_notes_organizer_archive__keep":{"content":""},"class_notes_organizer_handoff_README_txt":{"content":"Substitute teacher handoff\nBring math worksheets\n"},"class_notes_organizer_archive_math_txt":{"content":"Math notes\n"},"class_notes_organizer_archive_history_txt":{"content":"History notes\n"}}}}}},"safe-delete-with-rm":{"label":"Safe Delete with rm","summary":"Remove only clear temporary files, and learn when moving to trash is safer than deleting.","cards":{"sketch0":{"title":"Check before deleting"},"sketch1":{"title":"Remove one file with `rm`"},"sketch2":{"title":"When unsure, move instead of delete"},"quiz":{"title":"Practice check"}},"practice":{"sc-rm-purpose":{"title":"What `rm` does","prompt":"What does `rm tmp.txt` do?","hint":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","help":{"concept":"`rm` permanently removes one named file, so inspection and an exact path are part of the skill.","hint_1":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","hint_2":"After deletion, list the folder and confirm that the protected files remain. The current task asks: What does `rm tmp.txt` do?"},"options":{"a":"Removes the file `tmp.txt`","b":"Copies the file","c":"Prints the file content","d":"Changes folder"}},"mc-rm-safety":{"title":"Safe delete habits","prompt":"Which habits make deletion of one confirmed temporary file safer?","hint":"Inspect first, target one exact file, and verify afterward.","help":{"concept":"`rm` permanently removes one named file, so inspection and an exact path are part of the skill.","hint_1":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","hint_2":"After deletion, list the folder and confirm that the protected files remain. The current task asks: Which habits make deletion safer?"},"options":{"a":"Use `ls` before deleting","b":"Delete only the exact confirmed temporary file","c":"Use `rm -rf` when unsure","d":"List again after deletion to verify the result"}},"sc-uncertain-file":{"title":"When deletion is uncertain","prompt":"What is safer when you are not sure a file should be deleted?","hint":"Choose the action that keeps the file recoverable for review.","help":{"concept":"`rm` permanently removes one named file, so inspection and an exact path are part of the skill.","hint_1":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","hint_2":"After deletion, list the folder and confirm that the protected files remain. The current task asks: What is safer when you are not sure a file should be deleted?"},"options":{"a":"Move it to a review or archive folder","b":"Use sudo rm -rf","c":"Delete the whole folder","d":"Ignore the filename and delete anyway"}},"dr-safe-delete-flow":{"title":"Safe delete order","prompt":"Put the safe delete routine in order.","hint":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","help":{"concept":"`rm` permanently removes one named file, so inspection and an exact path are part of the skill.","hint_1":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","hint_2":"After deletion, list the folder and confirm that the protected files remain. The current task asks: Put the safe delete routine in order."},"tokens":{"t1":"List the folder","t2":"Remove only the exact temporary file","t3":"List again to verify"}}},"tryIt":{"allowReveal":true,"exercises":{"safe-delete-with-rm-try-it-1":{"title":"Inspect the print room first","prompt":"The print room has a test page and an event plan. Type `ls` first so you can read both names before deciding what is temporary. After typing the command, press **Enter** so the terminal runs it.","hint":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","help":{"concept":"`rm` permanently removes one named file, so inspection and an exact path are part of the skill.","hint_1":"Confirm the temporary file with `ls` or `cat`; do not add recursive flags or wildcards.","hint_2":"After deletion, list the folder and confirm that the protected files remain. The current task asks: The print room has a test page and an event plan. Type `ls` first so you can read both names before deciding what is temporary."},"starterCode":"# Use the terminal for this task.","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `ls` to inspect the print room first."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"print_room_print_test_txt":{"content":"Printer alignment test\n"},"print_room_event_plan_txt":{"content":"Keep this event plan\n"}}},"safe-delete-with-rm-try-it-2":{"title":"Try It: Remove One Confirmed Temporary File","prompt":"The cleanup desk contains `temp-label.txt` and `display-plan.txt`. Use `rm` to remove only the temporary label, then check the folder and make sure `display-plan.txt` is still there.","hint":"Name only the confirmed temporary file in the delete command.","help":{"concept":"`rm` permanently removes the named file in this workspace.","hint_1":"Delete only when the exact temporary target is known.","hint_2":"If uncertain, preserve the file in a review location instead."},"starterCode":"# Remove only the confirmed temporary file.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `rm temp-label.txt` to remove only the temporary file."},"1":{"message":"Use `ls` to confirm the important file remains."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"cleanup_desk_temp_label_txt":{"content":"Temporary printer label\n"},"cleanup_desk_display_plan_txt":{"content":"Keep the display plan\n"},"main_sh":{"content":"# Remove only the confirmed temporary file.\n"}},"solutionCode":"rm temp-label.txt\nls\n","solutionFiles":{"main_sh":{"content":"rm temp-label.txt\nls\n"},"cleanup_desk_display_plan_txt":{"content":"Keep the display plan\n"}}},"safe-delete-with-rm-try-it-3":{"title":"Practice: Preserve an Uncertain File","prompt":"You are not sure whether `maybe-archive.txt` can be deleted. Keep it instead: create a `review-later` folder, move the file there, and verify its new location.","hint":"Preserve uncertain work instead of deleting it.","help":{"concept":"`rm` permanently removes the named file in this workspace.","hint_1":"Delete only when the exact temporary target is known.","hint_2":"If uncertain, preserve the file in a review location instead."},"starterCode":"# Preserve the uncertain file in a review location.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Create the `review-later` folder."},"1":{"message":"Move the uncertain note instead of deleting it."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"archive_review_maybe_archive_txt":{"content":"Needs coordinator review\n"},"main_sh":{"content":"# Preserve the uncertain file in a review location.\n"}},"solutionCode":"mkdir -p review-later\nmv maybe-archive.txt review-later/maybe-archive.txt\nls review-later\n","solutionFiles":{"main_sh":{"content":"mkdir -p review-later\nmv maybe-archive.txt review-later/maybe-archive.txt\nls review-later\n"},"archive_review_review_later_maybe_archive_txt":{"content":"Needs coordinator review\n"}}}},"try_safe_delete_with_rm_sketch0":{"title":"Inspect the print room first","prompt":"List a new folder before removing anything. Press **Enter** to run the command."},"try_safe_delete_with_rm_sketch1":{"title":"Remove one temporary label","prompt":"Delete a different temporary file. Press **Enter** after each command."},"try_safe_delete_with_rm_sketch2":{"title":"Set aside an uncertain note","prompt":"Move an uncertain file instead of deleting it. Press **Enter** after each command."}}},"viewing-file-contents":{"label":"Viewing File Contents","summary":"Read text files with cat, preview long files with head and tail, and count lines with wc -l.","cards":{"sketch0":{"title":"Use `cat` for a small file"},"sketch1":{"title":"Use `head` and `tail` for previews"},"sketch2":{"title":"Use `wc -l` to count lines"},"quiz":{"title":"Practice check"}},"practice":{"sc-cat-use":{"title":"Best command for a short note","prompt":"Which command prints a whole short file?","hint":"Use the command named by the prompt on the provided file; no file creation is needed.","help":{"concept":"`cat` reads a short file, `head` and `tail` preview its edges, and `wc -l` counts lines.","hint_1":"Use the command named by the prompt on the provided file; no file creation is needed.","hint_2":"Compare the displayed content or count with the task and avoid changing the fixture file. The current task asks: Which command prints a whole short file?"},"options":{"a":"cat","b":"mkdir","c":"cd","d":"rm"}},"mc-preview-long-file":{"title":"Preview a long file","prompt":"Which commands help preview a long file without reading every line?","hint":"Use the command named by the prompt on the provided file; no file creation is needed.","help":{"concept":"`cat` reads a short file, `head` and `tail` preview its edges, and `wc -l` counts lines.","hint_1":"Use the command named by the prompt on the provided file; no file creation is needed.","hint_2":"Compare the displayed content or count with the task and avoid changing the fixture file. The current task asks: Which commands help preview a long file without reading every line?"},"options":{"a":"head","b":"tail","c":"touch","d":"pwd"}},"sc-wc-lines":{"title":"Count lines","prompt":"Which command counts lines in `names.txt`?","hint":"Use the command named by the prompt on the provided file; no file creation is needed.","help":{"concept":"`cat` reads a short file, `head` and `tail` preview its edges, and `wc -l` counts lines.","hint_1":"Use the command named by the prompt on the provided file; no file creation is needed.","hint_2":"Compare the displayed content or count with the task and avoid changing the fixture file. The current task asks: Which command counts lines in `names.txt`?"},"options":{"a":"wc -l names.txt","b":"cat -l names.txt","c":"mkdir names.txt","d":"cd names.txt"}},"dr-inspect-file":{"title":"Inspect and count for a handoff","prompt":"A handoff requires you to confirm the filename, inspect its content, and then record its line count. Put those required steps in order.","hint":"Confirm the target before reading it, then count after the content check.","help":{"concept":"`cat` reads a short file, `head` and `tail` preview its edges, and `wc -l` counts lines.","hint_1":"Use the command named by the prompt on the provided file; no file creation is needed.","hint_2":"Compare the displayed content or count with the task and avoid changing the fixture file. The current task asks: Put the file-inspection flow in order."},"tokens":{"t1":"Use `ls` to confirm the file name","t2":"Inspect the file content","t3":"Use `wc -l` to record the line count"}}},"tryIt":{"allowReveal":true,"exercises":{"viewing-file-contents-try-it-1":{"title":"Try It: Read a Welcome Note","prompt":"Use `cat welcome-note.txt` to read the complete visitor note in the terminal. Do not change the file.","hint":"This guided task prints the whole file without changing it.","help":{"concept":"`cat`, `head`, `tail`, and `wc -l` answer different inspection questions.","hint_1":"Choose the inspection command that matches the information you need.","hint_2":"These tasks should not modify the fixture file."},"starterCode":"# Read the short file in the terminal.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `cat welcome-note.txt` to read the note."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"visitor_desk_welcome_note_txt":{"content":"Welcome table opens at 9:00.\n"},"main_sh":{"content":"# Read the short file in the terminal.\n"}},"solutionCode":"cat welcome-note.txt\n","solutionFiles":{"main_sh":{"content":"cat welcome-note.txt\n"},"visitor_desk_welcome_note_txt":{"content":"Welcome table opens at 9:00.\n"}}},"viewing-file-contents-try-it-2":{"title":"Practice: Preview a Delivery Log","prompt":"The delivery log is long. Inspect both the beginning and the end of `delivery-log.txt` without printing the entire file.","hint":"Use the two preview commands designed for opposite ends of a file.","help":{"concept":"`cat`, `head`, `tail`, and `wc -l` answer different inspection questions.","hint_1":"Choose the inspection command that matches the information you need.","hint_2":"These tasks should not modify the fixture file."},"starterCode":"# Preview both ends of the delivery log.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `head delivery-log.txt` to see the beginning."},"1":{"message":"Use `tail delivery-log.txt` to see the end."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"dispatch_delivery_log_txt":{"content":"08:00 Chairs arrived\n08:20 Tables arrived\n08:45 Direction signs arrived\n09:10 Water station arrived\n09:30 Radios arrived\n10:00 Lunch boxes arrived\n10:25 Volunteer badges arrived\n10:50 First-aid kit arrived\n11:15 Stage cables arrived\n11:40 Registration forms arrived\n12:05 Workshop supplies arrived\n12:30 Recycling bins arrived\n12:55 Sound equipment arrived\n13:20 Final delivery completed\n"},"main_sh":{"content":"# Preview both ends of the delivery log.\n"}},"solutionCode":"head delivery-log.txt\ntail delivery-log.txt\n","solutionFiles":{"main_sh":{"content":"head delivery-log.txt\ntail delivery-log.txt\n"},"dispatch_delivery_log_txt":{"content":"08:00 Chairs arrived\n08:20 Tables arrived\n08:45 Signs arrived\n09:10 Water arrived\n09:30 Radios arrived\n10:00 Lunch arrived\n"}}},"viewing-file-contents-try-it-3":{"title":"Practice: Count Meal Requests","prompt":"`meal-requests.txt` stores one request per line. Find out how many requests are in the file.","hint":"Use the line-counting form of the word-count command.","help":{"concept":"`cat`, `head`, `tail`, and `wc -l` answer different inspection questions.","hint_1":"Choose the inspection command that matches the information you need.","hint_2":"These tasks should not modify the fixture file."},"starterCode":"# Count the line-based meal requests.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `wc -l meal-requests.txt` to count the lines."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"kitchen_meal_requests_txt":{"content":"Vegetarian\nStandard\nVegetarian\nGluten-free\nStandard\n"},"main_sh":{"content":"# Count the line-based meal requests.\n"}},"solutionCode":"wc -l meal-requests.txt\n","solutionFiles":{"main_sh":{"content":"wc -l meal-requests.txt\n"},"kitchen_meal_requests_txt":{"content":"Vegetarian\nStandard\nVegetarian\nGluten-free\nStandard\n"}}}},"try_viewing_file_contents_sketch0":{"title":"Read a visitor welcome note","prompt":"Use `cat` on a new short file. Press **Enter** to run the command."},"try_viewing_file_contents_sketch1":{"title":"Preview a delivery log","prompt":"Preview a different long file. Press **Enter** after each command."},"try_viewing_file_contents_sketch2":{"title":"Count meal requests","prompt":"Count lines in a different list. Press **Enter** to run the command."}}},"writing-text-into-files":{"label":"Writing Text into Files","summary":"Use echo, >, >>, and cat to put real text into files.","cards":{"sketch0":{"title":"`echo` prints text"},"sketch1":{"title":"Use `>` to write or replace a file"},"sketch2":{"title":"Use `>>` to add another line"},"quiz":{"title":"Practice check"}},"practice":{"sc-echo-purpose":{"title":"What `echo` does","prompt":"What does `echo \"Hello\"` do by itself?","hint":"Choose `>` for the first complete line and `>>` only when existing content must remain.","help":{"concept":"`echo` produces text, `>` writes or replaces a file, and `>>` appends without removing earlier lines.","hint_1":"Choose `>` for the first complete line and `>>` only when existing content must remain.","hint_2":"Read the file with `cat` and check the exact line order before submitting. The current task asks: What does `echo \"Hello\"` do by itself?"},"options":{"a":"Prints Hello in the terminal","b":"Deletes a file","c":"Moves into a folder","d":"Counts lines"}},"sc-write-symbol":{"title":"Write or replace","prompt":"Which symbol writes output into a file and can replace existing content?","hint":"Choose `>` for the first complete line and `>>` only when existing content must remain.","help":{"concept":"`echo` produces text, `>` writes or replaces a file, and `>>` appends without removing earlier lines.","hint_1":"Choose `>` for the first complete line and `>>` only when existing content must remain.","hint_2":"Read the file with `cat` and check the exact line order before submitting. The current task asks: Which symbol writes output into a file and can replace existing content?"},"options":{"a":"`>`","b":"`>>`","c":"`..`","d":"`~`"}},"sc-append-symbol":{"title":"Append safely","prompt":"Which symbol adds output to the end of a file?","hint":"Choose `>` for the first complete line and `>>` only when existing content must remain.","help":{"concept":"`echo` produces text, `>` writes or replaces a file, and `>>` appends without removing earlier lines.","hint_1":"Choose `>` for the first complete line and `>>` only when existing content must remain.","hint_2":"Read the file with `cat` and check the exact line order before submitting. The current task asks: Which symbol adds output to the end of a file?"},"options":{"a":"`>>`","b":"`>`","c":"cd","d":"pwd"}},"dr-write-check-flow":{"title":"Write and verify","prompt":"Put the file-writing routine in order.","hint":"Choose `>` for the first complete line and `>>` only when existing content must remain.","help":{"concept":"`echo` produces text, `>` writes or replaces a file, and `>>` appends without removing earlier lines.","hint_1":"Choose `>` for the first complete line and `>>` only when existing content must remain.","hint_2":"Read the file with `cat` and check the exact line order before submitting. The current task asks: Put the file-writing routine in order."},"tokens":{"t1":"Use `echo` with `>` to write the first line","t2":"Use `echo` with `>>` to add another line","t3":"Use `cat` to read the file"}}},"tryIt":{"allowReveal":true,"exercises":{"writing-text-into-files-try-it-1":{"title":"Try It: Print a Briefing","prompt":"Use `echo` to print `Morning briefing` in the terminal. This task should display the text only; do not save it to a file.","hint":"No file should be created in this guided task.","help":{"concept":"`echo` produces text; redirection decides whether that text is displayed, written, replaced, or appended.","hint_1":"Decide whether existing content must be preserved.","hint_2":"Read the finished file when the task changes file content."},"starterCode":"# Print the requested text without saving it.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `echo` to print `Morning briefing`."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"solutionCode":"echo \"Morning briefing\"\n","starterFiles":{"main_sh":{"content":"# Print the requested text without saving it.\n"}},"solutionFiles":{"main_sh":{"content":"echo \"Morning briefing\"\n"}}},"writing-text-into-files-try-it-2":{"title":"Practice: Write a Welcome Note","prompt":"Create `welcome-note.txt` with exactly one line: `Welcome volunteers`. Read the file afterward to confirm the text was written correctly.","hint":"Use redirection that establishes or replaces file content, then inspect the result.","help":{"concept":"`echo` produces text; redirection decides whether that text is displayed, written, replaced, or appended.","hint_1":"Decide whether existing content must be preserved.","hint_2":"Read the finished file when the task changes file content."},"starterCode":"# Write the requested first line and verify the file.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `echo` with `>` to write `welcome-note.txt`."},"1":{"message":"Use `cat welcome-note.txt` to read the file."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"solutionCode":"echo \"Welcome volunteers\" > welcome-note.txt\ncat welcome-note.txt\n","starterFiles":{"main_sh":{"content":"# Write the requested first line and verify the file.\n"}},"solutionFiles":{"main_sh":{"content":"echo \"Welcome volunteers\" > welcome-note.txt\ncat welcome-note.txt\n"},"welcome_note_txt":{"content":"Welcome volunteers\n"}}},"writing-text-into-files-try-it-3":{"title":"Practice: Preserve and Extend a Supply List","prompt":"`supply-list.txt` already contains one line. Add `Water bottles` to the end without replacing the existing content, then read the finished file.","hint":"Use the redirection form that preserves earlier lines.","help":{"concept":"`echo` produces text; redirection decides whether that text is displayed, written, replaced, or appended.","hint_1":"Decide whether existing content must be preserved.","hint_2":"Read the finished file when the task changes file content."},"starterCode":"# Extend the existing file without replacing it.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `>>` to append `Water bottles` to the supply list."},"1":{"message":"Use `cat supply-list.txt` to check the file."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"supply_list_txt":{"content":"Name tags\n"},"main_sh":{"content":"# Extend the existing file without replacing it.\n"}},"solutionCode":"echo \"Water bottles\" >> supply-list.txt\ncat supply-list.txt\n","solutionFiles":{"main_sh":{"content":"echo \"Water bottles\" >> supply-list.txt\ncat supply-list.txt\n"},"supply_list_txt":{"content":"Name tags\nWater bottles\n"}}}},"try_writing_text_into_files_sketch0":{"title":"Print the morning briefing","prompt":"Use `echo` to print a new message. Press **Enter** to run the command."},"try_writing_text_into_files_sketch1":{"title":"Write a volunteer welcome note","prompt":"Write a new line into `welcome-note.txt`. Press **Enter** after each command."},"try_writing_text_into_files_sketch2":{"title":"Add to the supply list","prompt":"Append a different line to a supply file. Press **Enter** after each command."}}}},"linux-module-3-final-capstone":{"final-capstone-file-room-handoff":{"label":"Final Capstone: Community Media Archive","summary":"Organize and verify a community media archive with the full beginner terminal toolkit.","cards":{"sketch0":{"title":"A media archive ready for the next team"},"project":{"title":"Build and verify the archive"}},"finalCapstone":{"steps":{"final-capstone-file-room-handoff-terminal-task-1":{"title":"Milestone 1: Build the Archive Structure","prompt":"Open `media-archive` and inspect what arrived. Create `organized/photos`, `organized/documents`, `backup`, and `review`, then add an empty `review/needs-review.txt` marker and verify the new structure.","hint":"Preserve every incoming file while adding only the required folders and review marker.","help":{"concept":"The capstone begins by adding structure without disturbing the incoming records.","hint_1":"Inspect first, then create the four requested destinations.","hint_2":"The review marker should exist but remain empty at this stage."},"starterCode":"# Build the media archive from the incoming files below.\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `pwd` to confirm the working location."},"1":{"message":"Use `ls` to inspect before and after the structure change."},"2":{"message":"Enter the archive with `cd`."},"3":{"message":"Create the required directories with `mkdir` or `mkdir -p`."},"4":{"message":"Create the review marker with `touch`."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"community_file_room_inbox_agenda_txt":{"content":"Community event agenda\n"},"community_file_room_inbox_guest_list_txt":{"content":"Guest list\n"},"community_file_room_inbox_venue_txt":{"content":"Venue note\n"},"community_file_room_inbox_tmp_scratch_txt":{"content":"temporary scratch\n"},"main_sh":{"content":"# Build the media archive from the incoming files below.\n"},"media_archive_inbox_photo_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_inbox_release_forms_txt":{"content":"Release forms received\n"},"media_archive_inbox_shoot_notes_txt":{"content":"Check captions and dates\n"},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"}},"solutionCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\n","solutionFiles":{"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\n"},"media_archive_backup__keep":{"content":""},"media_archive_inbox_photo_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_inbox_release_forms_txt":{"content":"Release forms received\n"},"media_archive_inbox_shoot_notes_txt":{"content":"Check captions and dates\n"},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_photos__keep":{"content":""},"media_archive_review_needs_review_txt":{"content":""}}},"final-capstone-file-room-handoff-terminal-task-2":{"title":"Milestone 2: Write the Archive Guide","prompt":"With the archive folders in place, create `organized/README.txt` with these three lines in order: `Community media archive`, `Photos go in organized/photos`, and `Documents go in organized/documents`. Put `Check image names before publishing` in `review/needs-review.txt`, then read both files.","hint":"Create the first README line, preserve it while adding the next two, and verify the finished text.","help":{"concept":"Redirection can create a file and append later lines while preserving earlier text.","hint_1":"The README must contain exactly three guide lines in order.","hint_2":"Read both written files before moving on."},"starterCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `echo` to produce the required text."},"1":{"message":"Use write-or-replace redirection for the first line."},"2":{"message":"Use append redirection for the later README lines."},"3":{"message":"Read the written files with `cat`."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"community_file_room_inbox_agenda_txt":{"content":"Community event agenda\n"},"community_file_room_inbox_guest_list_txt":{"content":"Guest list\n"},"community_file_room_inbox_venue_txt":{"content":"Venue note\n"},"community_file_room_inbox_tmp_scratch_txt":{"content":"temporary scratch\n"},"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\n"},"media_archive_backup__keep":{"content":""},"media_archive_inbox_photo_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_inbox_release_forms_txt":{"content":"Release forms received\n"},"media_archive_inbox_shoot_notes_txt":{"content":"Check captions and dates\n"},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_photos__keep":{"content":""},"media_archive_review_needs_review_txt":{"content":""}},"solutionCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\n","solutionFiles":{"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\n"},"media_archive_backup__keep":{"content":""},"media_archive_inbox_photo_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_inbox_release_forms_txt":{"content":"Release forms received\n"},"media_archive_inbox_shoot_notes_txt":{"content":"Check captions and dates\n"},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_photos__keep":{"content":""},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"}}},"final-capstone-file-room-handoff-terminal-task-3":{"title":"Milestone 3: Organize the Incoming Records","prompt":"Organize the incoming records. Put the photo index at `organized/photos/index.txt`, the release forms at `organized/documents/release-forms.txt`, and the shoot notes at `review/shoot-notes.txt`. Check the inbox and destination folders to confirm each file moved.","hint":"These are relocations, not copies; preserve each file's content at its destination.","help":{"concept":"Moving files changes their paths while preserving their contents.","hint_1":"The photo index is both moved and renamed.","hint_2":"Verify the new destinations and the cleaned old paths."},"starterCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `mv` for the three required relocations."},"1":{"message":"Use `ls` to verify the old and new locations."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"community_file_room_inbox_agenda_txt":{"content":"Community event agenda\n"},"community_file_room_inbox_guest_list_txt":{"content":"Guest list\n"},"community_file_room_inbox_venue_txt":{"content":"Venue note\n"},"community_file_room_inbox_tmp_scratch_txt":{"content":"temporary scratch\n"},"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\n"},"media_archive_backup__keep":{"content":""},"media_archive_inbox_photo_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_inbox_release_forms_txt":{"content":"Release forms received\n"},"media_archive_inbox_shoot_notes_txt":{"content":"Check captions and dates\n"},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_photos__keep":{"content":""},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"}},"solutionCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\n","solutionFiles":{"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\n"},"media_archive_backup__keep":{"content":""},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_documents_release_forms_txt":{"content":"Release forms received\n"},"media_archive_organized_photos__keep":{"content":""},"media_archive_organized_photos_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"},"media_archive_review_shoot_notes_txt":{"content":"Check captions and dates\n"}}},"final-capstone-file-room-handoff-terminal-task-4":{"title":"Milestone 4: Back Up and Remove the Temporary Import","prompt":"Create `backup/photo-index-backup.txt` from the organized photo index, keeping the original index in place. Then remove only `inbox/tmp-import.txt` and inspect the backup and inbox to verify both changes.","hint":"The original organized index must remain after the backup, and only the confirmed temporary import should be deleted.","help":{"concept":"A backup preserves the source; safe deletion targets one confirmed temporary file.","hint_1":"The organized photo index must survive the copy.","hint_2":"Do not use recursive deletion."},"starterCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `cp` to create the photo-index backup."},"1":{"message":"Use `rm` only for the confirmed temporary import."},"2":{"message":"Use `ls` to verify the backup and cleaned inbox."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"community_file_room_reports_guest_list_txt":{"content":"Guest list\n"},"community_file_room_inbox_tmp_scratch_txt":{"content":"temporary scratch\n"},"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\n"},"media_archive_backup__keep":{"content":""},"media_archive_inbox_tmp_import_txt":{"content":"temporary import cache\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_documents_release_forms_txt":{"content":"Release forms received\n"},"media_archive_organized_photos__keep":{"content":""},"media_archive_organized_photos_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"},"media_archive_review_shoot_notes_txt":{"content":"Check captions and dates\n"}},"solutionCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\ncp organized/photos/index.txt backup/photo-index-backup.txt\nrm inbox/tmp-import.txt\nls backup inbox\n","solutionFiles":{"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\ncp organized/photos/index.txt backup/photo-index-backup.txt\nrm inbox/tmp-import.txt\nls backup inbox\n"},"media_archive_backup__keep":{"content":""},"media_archive_backup_photo_index_backup_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_documents_release_forms_txt":{"content":"Release forms received\n"},"media_archive_organized_photos__keep":{"content":""},"media_archive_organized_photos_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"},"media_archive_review_shoot_notes_txt":{"content":"Check captions and dates\n"}}},"final-capstone-file-room-handoff-terminal-task-5":{"title":"Milestone 5: Verify and Mark the Archive Ready","prompt":"Before marking the archive ready, verify your location, inspect the organized folders, read `organized/README.txt`, and check the line count of `organized/photos/index.txt`. When those checks look right, create `organized/READY.txt` with `Media archive verified` and display the marker.","hint":"The READY marker is the final action; create it only after the archive evidence has been checked.","help":{"concept":"A final handoff should be supported by filesystem and file content checks before it is marked ready.","hint_1":"Verify the archive before creating READY.txt.","hint_2":"The READY marker should contain the requested verification text."},"starterCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\ncp organized/photos/index.txt backup/photo-index-backup.txt\nrm inbox/tmp-import.txt\nls backup inbox\n","terminalExpectations":{"requiredCommands":{"0":{"message":"Use `pwd` as part of the final location check."},"1":{"message":"Use targeted `ls` commands to inspect the finished archive."},"2":{"message":"Use `cat` to read the README and READY marker."},"3":{"message":"Use `wc -l` to count the photo-index lines."},"4":{"message":"Use `echo` to produce the READY text."},"5":{"message":"Redirect the READY text into the marker file."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}},"starterFiles":{"community_file_room_reports_guest_list_txt":{"content":"Guest list\n"},"community_file_room_handoff_readme_txt":{"content":"Community file room handoff\n"},"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\ncp organized/photos/index.txt backup/photo-index-backup.txt\nrm inbox/tmp-import.txt\nls backup inbox\n"},"media_archive_backup__keep":{"content":""},"media_archive_backup_photo_index_backup_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_documents_release_forms_txt":{"content":"Release forms received\n"},"media_archive_organized_photos__keep":{"content":""},"media_archive_organized_photos_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"},"media_archive_review_shoot_notes_txt":{"content":"Check captions and dates\n"}},"solutionCode":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\ncp organized/photos/index.txt backup/photo-index-backup.txt\nrm inbox/tmp-import.txt\nls backup inbox\npwd\nls organized/photos organized/documents backup review\ncat organized/README.txt\nwc -l organized/photos/index.txt\necho \"Media archive verified\" > organized/READY.txt\ncat organized/READY.txt\n","solutionFiles":{"main_sh":{"content":"pwd\nls media-archive\ncd media-archive\npwd\nmkdir -p organized/photos organized/documents backup review\ntouch review/needs-review.txt\nls organized review\necho \"Community media archive\" > organized/README.txt\necho \"Photos go in organized/photos\" >> organized/README.txt\necho \"Documents go in organized/documents\" >> organized/README.txt\necho \"Check image names before publishing\" > review/needs-review.txt\ncat organized/README.txt\ncat review/needs-review.txt\nls inbox\nmv inbox/photo-index.txt organized/photos/index.txt\nmv inbox/release-forms.txt organized/documents/release-forms.txt\nmv inbox/shoot-notes.txt review/shoot-notes.txt\nls inbox organized/photos organized/documents review\ncp organized/photos/index.txt backup/photo-index-backup.txt\nrm inbox/tmp-import.txt\nls backup inbox\npwd\nls organized/photos organized/documents backup review\ncat organized/README.txt\nwc -l organized/photos/index.txt\necho \"Media archive verified\" > organized/READY.txt\ncat organized/READY.txt\n"},"media_archive_backup__keep":{"content":""},"media_archive_backup_photo_index_backup_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_organized_README_txt":{"content":"Community media archive\nPhotos go in organized/photos\nDocuments go in organized/documents\n"},"media_archive_organized_READY_txt":{"content":"Media archive verified\n"},"media_archive_organized_documents__keep":{"content":""},"media_archive_organized_documents_release_forms_txt":{"content":"Release forms received\n"},"media_archive_organized_photos__keep":{"content":""},"media_archive_organized_photos_index_txt":{"content":"IMG_001.jpg\nIMG_002.jpg\nIMG_003.jpg\n"},"media_archive_review_needs_review_txt":{"content":"Check image names before publishing\n"},"media_archive_review_shoot_notes_txt":{"content":"Check captions and dates\n"}}}}},"practice":{"practice-final-capstone-handoff-check":{"title":"Practice: Clean a Small Handoff Folder","prompt":"A small handoff folder contains one real agenda and one confirmed temporary note. Move the agenda from the inbox into the archive, remove only the temporary note, and inspect both folders to confirm the final state.","hint":"Preserve the real record, delete only the explicitly temporary file, and verify the result.","help":{"concept":"An integrated handoff can combine inspection, moving, safe single-file deletion, and final verification.","hint_1":"The agenda should survive in the archive.","hint_2":"The temporary note should be the only deleted file."},"starterCode":"# Complete the handoff practice below.\n","solutionCode":"pwd\nls handoff-practice/inbox\nmv handoff-practice/inbox/agenda.txt handoff-practice/archive/agenda.txt\nrm handoff-practice/inbox/tmp-note.txt\nls handoff-practice/archive handoff-practice/inbox\n","starterFiles":{"main_sh":{"content":"# Complete the handoff practice below.\n"},"handoff_practice_archive__keep":{"content":""},"handoff_practice_inbox_agenda_txt":{"content":"Community agenda\n"},"handoff_practice_inbox_tmp_note_txt":{"content":"temporary note\n"}},"solutionFiles":{"main_sh":{"content":"pwd\nls handoff-practice/inbox\nmv handoff-practice/inbox/agenda.txt handoff-practice/archive/agenda.txt\nrm handoff-practice/inbox/tmp-note.txt\nls handoff-practice/archive handoff-practice/inbox\n"},"handoff_practice_archive__keep":{"content":""},"handoff_practice_archive_agenda_txt":{"content":"Community agenda\n"}},"terminalExpectations":{"requiredCommands":{"0":{"message":"Confirm the starting location with `pwd`."},"1":{"message":"Inspect the handoff folders with `ls`."},"2":{"message":"Move the real agenda with `mv`."},"3":{"message":"Remove only the confirmed temporary note with `rm`."}},"forbiddenCommands":{"0":{"message":"Do not use sudo in this beginner workspace."},"1":{"message":"Do not use recursive rm in this course."},"2":{"message":"Permissions commands are not needed for this workspace."},"3":{"message":"Do not download anything for this exercise."}}}}}}}},"applied-python-projects":{"python-10-testing-debugging-oop-projects":{"debugging-imports-and-state":{"label":"Debugging Imports and State","summary":"Debug three different failure sources deliberately: a wrong module path, shared mutable constructor state, and a method that reports success without changing object state.","cards":{"sketch0":{"title":"Trace a broken import"},"sketch1":{"title":"Trace shared mutable state"},"sketch2":{"title":"Trace a missing state mutation"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_debugging_imports_and_state_sketch0":{"title":"Fix the module path without rewriting Book","prompt":"`models/book.py` is already correct. `main.py` fails because its import path does not match the file tree. Fix the import so the `Book` class is loaded from `models/book.py`. Leave the model unchanged. The rest of `main.py` should keep reading a title and author and printing `book.summary()`.","hint":"The folder is `models` and the file is `book.py`.","help":{"concept":"The module path mirrors the folder and Python filename: `models/book.py` becomes `models.book`.","hint_1":"Do not move or duplicate the Book class.","hint_2":"Fix the import in `main.py`."},"starterCode":"# The Book model is correct. Debug only the import path.\nfrom book import Book\n\ntitle = input()\nauthor = input()\n\nbook = Book(title, author)\nprint(book.summary())\n","starterFiles":{"main_py":{"content":"# The Book model is correct. Debug only the import path.\nfrom book import Book\n\ntitle = input()\nauthor = input()\n\nbook = Book(title, author)\nprint(book.summary())\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title, author):\n self.title = title\n self.author = author\n\n def summary(self):\n return f\"{self.title} by {self.author}\"\n"}},"solutionFiles":{"main_py":{"content":"# The Book model is correct. Debug only the import path.\nfrom models.book import Book\n\ntitle = input()\nauthor = input()\n\nbook = Book(title, author)\nprint(book.summary())\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title, author):\n self.title = title\n self.author = author\n\n def summary(self):\n return f\"{self.title} by {self.author}\"\n"}},"solutionCode":"# The Book model is correct. Debug only the import path.\nfrom models.book import Book\n\ntitle = input()\nauthor = input()\n\nbook = Book(title, author)\nprint(book.summary())\n","checks":{"0":{"message":"Keep Book.summary() working."},"1":{"message":"Fix the import so main.py prints the summary."}},"expectedOutput":"The Hobbit by Tolkien","sourceChecks":{"0":{"message":"Import `Book` through the `models.book` module path rather than from a nonexistent top-level `book` module."}}},"try_debugging_imports_and_state_sketch1":{"title":"Stop ReadingList objects from sharing one default list","prompt":"`main.py` already reproduces the bug with two ReadingList objects. In `models/reading_list.py`, replace the mutable `books=[]` default with `books=None`. When `books is None`, create a new empty list for that instance; when a list is explicitly provided, keep that provided list. Leave `add_book()`, `count()`, and `main.py` unchanged.","hint":"The default itself must not be a list. Create the empty list inside the constructor only when no list was passed.","help":{"concept":"Mutable default arguments are shared across calls. A `None` sentinel lets each default-constructed object receive fresh state.","hint_1":"Change only the constructor logic that initializes `books`.","hint_2":"Preserve an explicitly supplied list."},"starterCode":"from models.reading_list import ReadingList\n\nfirst_owner = input()\nsecond_owner = input()\ntitle = input()\n\nfirst = ReadingList(first_owner)\nsecond = ReadingList(second_owner)\nfirst.add_book(title)\n\nprovided = ReadingList(\"Provided\", [\"Existing\"])\n\nprint(f\"{first.owner}: {first.count()}\")\nprint(f\"{second.owner}: {second.count()}\")\nprint(f\"{provided.owner}: {provided.count()}\")\n","starterFiles":{"main_py":{"content":"from models.reading_list import ReadingList\n\nfirst_owner = input()\nsecond_owner = input()\ntitle = input()\n\nfirst = ReadingList(first_owner)\nsecond = ReadingList(second_owner)\nfirst.add_book(title)\n\nprovided = ReadingList(\"Provided\", [\"Existing\"])\n\nprint(f\"{first.owner}: {first.count()}\")\nprint(f\"{second.owner}: {second.count()}\")\nprint(f\"{provided.owner}: {provided.count()}\")\n"},"models_reading_list_py":{"content":"class ReadingList:\n def __init__(self, owner, books=[]):\n self.owner = owner\n self.books = books\n\n def add_book(self, title):\n self.books.append(title)\n\n def count(self):\n return len(self.books)\n"}},"solutionFiles":{"main_py":{"content":"from models.reading_list import ReadingList\n\nfirst_owner = input()\nsecond_owner = input()\ntitle = input()\n\nfirst = ReadingList(first_owner)\nsecond = ReadingList(second_owner)\nfirst.add_book(title)\n\nprovided = ReadingList(\"Provided\", [\"Existing\"])\n\nprint(f\"{first.owner}: {first.count()}\")\nprint(f\"{second.owner}: {second.count()}\")\nprint(f\"{provided.owner}: {provided.count()}\")\n"},"models_reading_list_py":{"content":"class ReadingList:\n def __init__(self, owner, books=None):\n if books is None:\n books = []\n\n self.owner = owner\n self.books = books\n\n def add_book(self, title):\n self.books.append(title)\n\n def count(self):\n return len(self.books)\n"}},"solutionCode":"from models.reading_list import ReadingList\n\nfirst_owner = input()\nsecond_owner = input()\ntitle = input()\n\nfirst = ReadingList(first_owner)\nsecond = ReadingList(second_owner)\nfirst.add_book(title)\n\nprovided = ReadingList(\"Provided\", [\"Existing\"])\n\nprint(f\"{first.owner}: {first.count()}\")\nprint(f\"{second.owner}: {second.count()}\")\nprint(f\"{provided.owner}: {provided.count()}\")\n","checks":{"0":{"message":"Keep the ReadingList class in the model file."},"1":{"message":"The first list should contain one book while the second remains empty."}},"expectedOutput":"Ava: 1\nNoah: 0\nProvided: 1","sourceChecks":{"0":{"message":"Use `books=None` instead of a mutable list default."},"1":{"message":"Handle the `books is None` case inside the constructor so a fresh list is created per default-constructed object."}}},"try_debugging_imports_and_state_sketch2":{"title":"Fix a method that returns success but forgets state","prompt":"`Task.complete()` currently returns `True` but leaves `task.done` as `False`. In `models/task.py`, fix the existing `complete(self)` method so it sets `self.done = True` before returning `True`. Repeated calls must still leave the task completed. Leave `main.py` and the constructor unchanged.","hint":"The return value already says success. Repair the missing object state transition inside `complete()`.","help":{"concept":"A state-changing method must update the object's stored state, not only return a success value.","hint_1":"The attribute to change is `self.done`.","hint_2":"Set it before the existing `return True`."},"starterCode":"from models.task import Task\n\ntitle = input()\ntask = Task(title)\n\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\n","starterFiles":{"main_py":{"content":"from models.task import Task\n\ntitle = input()\ntask = Task(title)\n\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\n"},"models_stock_item_py":{"content":"class StockItem:\n def __init__(self, name, quantity):\n self.name = name\n self.quantity = quantity\n\n def sell(self, amount):\n # TODO: subtract only a positive amount that is not greater than quantity.\n pass\n\n def get_quantity(self):\n return self.quantity\n"},"models_task_py":{"content":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n # BUG: this reports success but never changes the object's state.\n return True\n"}},"solutionFiles":{"main_py":{"content":"from models.task import Task\n\ntitle = input()\ntask = Task(title)\n\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\n"},"models_stock_item_py":{"content":"class StockItem:\n def __init__(self, name, quantity):\n self.name = name\n self.quantity = quantity\n\n def sell(self, amount):\n if 0 < amount <= self.quantity:\n self.quantity -= amount\n return self.quantity\n\n def get_quantity(self):\n return self.quantity\n"},"models_task_py":{"content":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n self.done = True\n return True\n"}},"solutionCode":"from models.task import Task\n\ntitle = input()\ntask = Task(title)\n\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\nprint(task.complete())\nprint(f\"{task.title}: {task.done}\")\n","checks":{"0":{"message":"A valid sale should reduce the quantity."},"1":{"message":"An oversized sale should leave the quantity unchanged."},"2":{"message":"Print both returned quantities."}},"expectedOutput":"Ship release: False\nTrue\nShip release: True\nTrue\nShip release: True","sourceChecks":{"0":{"message":"Update `self.done` to `True` inside `complete()` rather than only returning a success value."}}}},"practice":{"q-debugging-imports-state-single-1":{"title":"Locate an import-path bug","prompt":"`models/book.py` defines `Book`, but `main.py` says `from book import Book`. Which layer should you fix first?","hint":"Compare the import path with the file tree.","help":{"concept":"When the class is already correct, repair the module path rather than rewriting the model.","hint_1":"The file lives inside `models/`.","hint_2":"The import should refer to that package/module path."},"options":{"a":"Rewrite the Book class in main.py","b":"Fix main.py to import Book through the models.book module","c":"Delete models/book.py","d":"Rename Book to match the broken import"}},"q-debugging-imports-state-multi-1":{"title":"Diagnose shared mutable state","prompt":"Which TWO observations strongly point to a shared mutable default argument bug?","hint":"Think about state unexpectedly appearing in another instance.","help":{"concept":"A mutable default can make separately constructed objects share one list across constructor calls.","hint_1":"Look for interaction between two supposedly separate objects.","hint_2":"Look for a list literal used as a default parameter value."},"options":{"a":"Adding a book to one default-constructed ReadingList changes another one's count","b":"Two objects have different owner names","c":"The constructor signature uses `books=[]`","d":"A method returns the length of its own list"}},"q-debugging-imports-state-multi-2":{"title":"Debug a state-changing method","prompt":"`task.complete()` returns `True`, but `task.done` remains `False`. Which TWO checks are most useful?","hint":"Separate the method's return value from the object's stored state.","help":{"concept":"A successful return value does not prove the object's state was updated.","hint_1":"Inspect the state after the call.","hint_2":"Inspect whether the method actually assigns the state attribute."},"options":{"a":"Check `task.done` after calling `complete()`","b":"Check whether `complete()` assigns `self.done = True`","c":"Rename the Task class","d":"Change the import path even though the module loads correctly"}},"q-debugging-imports-state-fill-1":{"title":"Complete a safe default parameter","prompt":"Fill in the missing default value so the constructor avoids a shared mutable list.","hint":"Use a non-mutable placeholder instead of `[]`.","help":{"concept":"Use an immutable sentinel default, then create a new list inside the constructor so instances never share one mutable default.","hint_1":"The blank should not be a list literal.","hint_2":"Choose the special Python value commonly used to mean 'no value was passed'."},"template":"def __init__(self, books=[blank1]):","choices":["None","[]","{}","0"]},"q-debugging-imports-state-fill-2":{"title":"Complete the package import","prompt":"Fill in the missing module name for this import from a `models` package.","hint":"Import from the module whose file actually defines the class named in the prompt.","help":{"concept":"In `from package.module import Name`, the module part is the file name without `.py`.","hint_1":"Separate the class name from the module path: the blank belongs to the file path portion of the import.","hint_2":"For a file inside models/, the module segment matches the Python filename without the .py extension."},"template":"from models.[blank1] import Book","choices":["book","Lesson notes panel","models","import"]},"q-debugging-imports-state-order-1":{"title":"Order a state-debugging workflow","prompt":"Put these steps in a sensible order for debugging a method that changes object state.","hint":"Start by observing the initial state before calling the method.","help":{"concept":"A clear debugging workflow checks the starting state, performs one action, then verifies the resulting state so you can isolate where the bug appears.","hint_1":"The method call belongs in the middle, between the before-check and after-check.","hint_2":"Finish by comparing the actual new state with the expected rule for that method."},"tokens":{"t1":"Create the object with a known starting value","t2":"Check the relevant attribute before the method call","t3":"Call the state-changing method once","t4":"Check the attribute again after the call"}},"ci-debugging-imports-and-state-4":{"title":"Fix a service import and keep the report working","prompt":"A classroom catalog app has a report service that should import `CatalogItem` from the models package and format one line of text. Fix the broken import in `services/report_service.py` so `main.py` prints `Marker: 8`. Keep the existing function and class names.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.catalog_item import CatalogItem\nfrom services.report_service import format_item\n\nitem = CatalogItem(\"Marker\", 8)\nprint(format_item(item))","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom services.report_service import format_item\n\nitem = CatalogItem(\"Marker\", 8)\nprint(format_item(item))"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title, quantity):\n self.title = title\n self.quantity = quantity"},"services_report_service_py":{"content":"from model.catalog_item import CatalogItem\n\ndef format_item(item: CatalogItem):\n return f\"{item.title}: {item.quantity}\""}},"solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom services.report_service import format_item\n\nitem = CatalogItem(\"Marker\", 8)\nprint(format_item(item))"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title, quantity):\n self.title = title\n self.quantity = quantity"},"services_report_service_py":{"content":"from models.catalog_item import CatalogItem\n\ndef format_item(item: CatalogItem):\n return f\"{item.title}: {item.quantity}\""}},"solutionCode":"from models.catalog_item import CatalogItem\nfrom services.report_service import format_item\n\nitem = CatalogItem(\"Marker\", 8)\nprint(format_item(item))","checks":{"0":{"message":"Program should print one formatted report line."}}},"ci-debugging-imports-and-state-5":{"title":"Repair independent cart state in a model file","prompt":"A snack shop app stores cart items in a `Cart` class inside `models/cart.py`. Right now two carts share the same default list. Fix the constructor so separate carts keep separate state, and keep the existing `add_item` and `item_count` methods.","hint":"The bug starts in the constructor parameter list.","help":{"concept":"Each object should own its own mutable state unless you intentionally pass in a shared object.","hint_1":"Avoid using `[]` directly as the default parameter value.","hint_2":"Use a placeholder default, then create a fresh list inside `__init__` when needed."},"starterCode":"from models.cart import Cart\n\nfirst = Cart(\"Ava\")\nsecond = Cart(\"Ben\")\nfirst.add_item(\"chips\")\nprint(first.item_count())\nprint(second.item_count())","starterFiles":{"main_py":{"content":"from models.cart import Cart\n\nfirst = Cart(\"Ava\")\nsecond = Cart(\"Ben\")\nfirst.add_item(\"chips\")\nprint(first.item_count())\nprint(second.item_count())"},"models_init_py":{"content":"# package marker"},"models_cart_py":{"content":"class Cart:\n def __init__(self, owner, items=[]):\n self.owner = owner\n self.items = items\n\n def add_item(self, name):\n self.items.append(name)\n\n def item_count(self):\n return len(self.items)"}},"solutionFiles":{"models_init_py":{"content":"# package marker"},"models_cart_py":{"content":"class Cart:\n def __init__(self, owner, items=None):\n self.owner = owner\n self.items = [] if items is None else list(items)\n\n def add_item(self, name):\n self.items.append(name)\n\n def item_count(self):\n return len(self.items)"},"main_py":{"content":"from models.cart import Cart\n\nfirst = Cart(\"Ava\")\nsecond = Cart(\"Ben\")\nfirst.add_item(\"chips\")\nprint(first.item_count())\nprint(second.item_count())"}},"solutionCode":"from models.cart import Cart\n\nfirst = Cart(\"Ava\")\nsecond = Cart(\"Ben\")\nfirst.add_item(\"chips\")\nprint(first.item_count())\nprint(second.item_count())"},"ci-debugging-imports-and-state-6":{"title":"Fix a state-changing method in a task model","prompt":"A project tracker has a `Task` class with a `complete()` method. Right now the method returns `True` but forgets to update the object's `done` attribute. Fix the method so the object's state changes correctly and repeated calls still leave it completed.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.task import Task\n\ntask = Task(\"Write report\")\nprint(task.is_done())\ntask.complete()\nprint(task.is_done())","starterFiles":{"main_py":{"content":"from models.task import Task\n\ntask = Task(\"Write report\")\nprint(task.is_done())\ntask.complete()\nprint(task.is_done())"},"models_init_py":{"content":"# package marker"},"models_task_py":{"content":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n return True\n\n def is_done(self):\n return self.done"}},"solutionFiles":{"models_init_py":{"content":"# package marker"},"models_task_py":{"content":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n self.done = True\n\n def is_done(self):\n return self.done"},"main_py":{"content":"from models.task import Task\n\ntask = Task(\"Write report\")\nprint(task.is_done())\ntask.complete()\nprint(task.is_done())"}},"solutionCode":"from models.task import Task\n\ntask = Task(\"Write report\")\nprint(task.is_done())\ntask.complete()\nprint(task.is_done())"}}},"module-10-oop-quality-project":{"label":"Module 10 Animal Shelter Quality Project","summary":"Stabilize Harbor Street Animal Shelter's intake app before a busy adoption weekend by adding regression tests and repairing real defects.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Animal Shelter Quality Pass"}},"projectSteps":{"try_module_10_oop_quality_project_sketch0":{"title":"Milestone 1: write model regression tests"},"project_step_report_service_tests":{"title":"Milestone 2: refactor and test mixed reporting"},"project_step_storage_loader":{"title":"Milestone 3: debug and test the CSV loader"},"project_step_debug_imports_state":{"title":"Milestone 4: reproduce and fix adoption state"},"project_step_regression_summary":{"title":"Milestone 5: build and test the cumulative summary"},"project_step_final_regression":{"title":"Milestone 6: finish the full regression suite"}},"moduleProject":{"steps":{"try_module_10_oop_quality_project_sketch0":{"title":"Milestone 1: write model regression tests","prompt":"`ShelterPet` and `FosterPet` are supplied production classes. In `tests/check_model.py`, use the provided `pet` and `foster` fixtures to write meaningful assertions for stored pet state, initial availability, the `FosterPet` inheritance relationship, and the overridden `adoption_label()` result. Also verify that constructing a ShelterPet with age `-1` raises `ValueError`. Do not repair `mark_adopted()` yet; that intentional bug belongs to a later milestone. Keep the final `model tests passed` print.","hint":"This is a testing milestone: production models stay supplied. Assert observable state and behavior instead of rebuilding them.","help":{"concept":"A useful model regression test protects constructor state, validation, inheritance, and an override contract.","hint_1":"Check the supplied `pet` attributes and availability.","hint_2":"Check that `foster` is a ShelterPet and uses its specialized label."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\n# Add meaningful model/inheritance assertions here.\n\nprint(\"model tests passed\")\n","starterFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nlines = []\nfor pet in pets:\n lines.append(pet.adoption_label())\n\nprint(\", \".join(lines))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\n# Add meaningful model/inheritance assertions here.\n\nprint(\"model tests passed\")\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"}},"solutionFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nlines = []\nfor pet in pets:\n lines.append(pet.adoption_label())\n\nprint(\", \".join(lines))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n","checks":{"0":{"message":"Store all pet attributes and the adopted state."},"1":{"message":"A new pet should be available."},"2":{"message":"Keep main.py runnable."}},"expectedOutput":"model tests passed","sourceChecks":{"0":{"message":"Assert both stored model state and the new pet's initial availability."},"1":{"message":"Assert the FosterPet inheritance relationship and specialized adoption label."},"2":{"message":"Exercise the negative-age case and handle the expected `ValueError`."}}},"project_step_report_service_tests":{"title":"Milestone 2: refactor and test mixed reporting","prompt":"Continue from the exact Milestone 1 workspace. `main.py` currently owns a working list-wide label loop. Refactor that collection coordination into `adoption_labels(pets)` in `services/reporting.py`; it must call each object's shared `adoption_label()` method without branching on concrete types. Also implement `young_pet_names(pets, max_age)` so it returns matching names in input order. Update `main.py` to import and use `adoption_labels()` instead of keeping the old loop. Then complete `tests/check_reporting.py` with assertions for both provided mixed ShelterPet/FosterPet fixtures and both age limits. Keep `build_summary()` unfinished for Milestone 5.","hint":"The refactor moves list-wide work only. Each model already owns its own `adoption_label()` behavior.","help":{"concept":"This milestone retrieves service refactoring plus regression testing of a mixed polymorphic collection.","hint_1":"The service should call `pet.adoption_label()` uniformly.","hint_2":"The test should compare exact ordered lists for normal and reversed mixed fixtures."},"starterCode":"# Added in Milestone 2.\n","starterFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nlines = []\nfor pet in pets:\n lines.append(pet.adoption_label())\n\nprint(\", \".join(lines))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n # Added in Milestone 2.\n pass\n\n\ndef young_pet_names(pets, max_age):\n # Added in Milestone 2.\n pass\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"tests_check_reporting_py":{"content":"# Added in Milestone 2.\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"}},"solutionFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nprint(\", \".join(adoption_labels(pets)))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n","checks":{"0":{"message":"Return values that produce the exact two-line shelter report."}},"expectedOutput":"reporting tests passed","sourceChecks":{"0":{"message":"`adoption_labels(pets)` should use the shared `adoption_label()` contract without concrete-type branching."},"1":{"message":"Remove the old list loop from main.py and call `adoption_labels(pets)` instead."},"2":{"message":"Assert the ordered labels for both supplied mixed fixtures."},"3":{"message":"Assert the young-pet filtering result for both supplied fixtures."}}},"project_step_storage_loader":{"title":"Milestone 3: debug and test the CSV loader","prompt":"Continue from the exact Milestone 2 workspace. `storage/pet_loader.py` has a real import-path bug: its model imports do not match the `models/` file tree. Fix those imports without rewriting the already-complete loader body. Then complete `tests/check_loader.py` so it loads `data/pets.csv` and asserts row order, converted integer ages, ShelterPet/FosterPet object types, and Pepper's foster label. Keep every earlier test file present and unchanged.","hint":"Debug the layer that is actually broken: the loader body already works once its module paths match the file tree.","help":{"concept":"This milestone retrieves import debugging and tests the storage boundary from CSV rows to real model objects.","hint_1":"`models/shelter_pet.py` maps to the `models.shelter_pet` module.","hint_2":"The CSV's foster row should become a FosterPet."},"starterCode":"# Added in Milestone 3.\n","starterFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nprint(\", \".join(adoption_labels(pets)))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom shelter_pet import ShelterPet\nfrom foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_loader_py":{"content":"# Added in Milestone 3.\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"}},"solutionFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nprint(\", \".join(adoption_labels(pets)))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n","checks":{"0":{"message":"Load all three CSV rows as ShelterPet objects."}},"expectedOutput":"loader tests passed","sourceChecks":{"0":{"message":"Import `ShelterPet` through the `models.shelter_pet` module path."},"1":{"message":"Import `FosterPet` through the `models.foster_pet` module path."},"2":{"message":"Assert the loaded row order and converted integer ages."},"3":{"message":"Assert that the foster CSV row becomes a FosterPet with its specialized label."}}},"project_step_debug_imports_state":{"title":"Milestone 4: reproduce and fix adoption state","prompt":"Continue from the exact Milestone 3 workspace. `ShelterPet.mark_adopted()` currently returns `True` but never updates the object's `adopted` state. First complete `tests/check_adoption.py` so the supplied pet is checked before adoption, after the first `mark_adopted()` call, and after a second call. Then repair `mark_adopted()` in `models/shelter_pet.py` by setting `self.adopted = True` before returning the new value. Keep all earlier production code and tests unchanged.","hint":"A successful return value and a stored state transition are two different things. Your test should prove both.","help":{"concept":"This milestone retrieves object-state testing and debugging of a method that reports success without mutating state.","hint_1":"The pet starts available.","hint_2":"Repeated adoption calls should leave the pet unavailable."},"starterCode":"# Added in Milestone 4.\n","starterFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nprint(\", \".join(adoption_labels(pets)))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n # BUG: this reports success but does not update adopted state.\n return True\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_adoption_py":{"content":"# Added in Milestone 4.\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"}},"solutionFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nprint(\", \".join(adoption_labels(pets)))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n self.adopted = True\n return self.adopted\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_adoption_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\n\npet = ShelterPet(\"Luna\", \"dog\", 5)\n\nassert pet.is_available() is True\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\n\nprint(\"adoption tests passed\")\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\n\npet = ShelterPet(\"Luna\", \"dog\", 5)\n\nassert pet.is_available() is True\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\n\nprint(\"adoption tests passed\")\n","checks":{"0":{"message":"mark_adopted() should return the new adopted state."},"1":{"message":"Print the adopted result and the updated availability."}},"expectedOutput":"adoption tests passed","sourceChecks":{"0":{"message":"Update `self.adopted` inside `mark_adopted()` instead of only returning success."},"1":{"message":"Test the same pet before adoption, after the first call, and after a repeated call."}}},"project_step_regression_summary":{"title":"Milestone 5: build and test the cumulative summary","prompt":"Continue from the exact Milestone 4 workspace. Implement `build_summary(pets, max_age)` in `services/reporting.py`. Return a dictionary with `total_pets`, `available_labels`, and `young_pet_count`. `available_labels` must preserve input order, include only pets whose `is_available()` is true, and use each pet's own `adoption_label()` method. Compute `young_pet_count` from the existing `young_pet_names(pets, max_age)` helper instead of duplicating its age rule. Complete `tests/check_summary.py` with the supplied CSV/adoption workflow, and update `main.py` to display the same three summary values.","hint":"Reuse the contracts already protected by earlier milestones: loader objects, adoption state, polymorphic labels, and the young-pet helper.","help":{"concept":"A cumulative integration test protects multiple already-tested boundaries without reimplementing them.","hint_1":"Filter availability with `pet.is_available()` and format with `pet.adoption_label()`.","hint_2":"Use `len(young_pet_names(pets, max_age))` for the count."},"starterCode":"# Added in Milestone 5.\n","starterFiles":{"main_py":{"content":"from models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels\n\npets = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nprint(\", \".join(adoption_labels(pets)))\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n self.adopted = True\n return self.adopted\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n # Added in Milestone 5.\n pass\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_summary_py":{"content":"# Added in Milestone 5.\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"},"tests_check_adoption_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\n\npet = ShelterPet(\"Luna\", \"dog\", 5)\n\nassert pet.is_available() is True\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\n\nprint(\"adoption tests passed\")\n"}},"solutionFiles":{"main_py":{"content":"from services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nprint(summary[\"total_pets\"])\nprint(\", \".join(summary[\"available_labels\"]))\nprint(summary[\"young_pet_count\"])\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n self.adopted = True\n return self.adopted\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n return {\n \"total_pets\": len(pets),\n \"available_labels\": [\n pet.adoption_label()\n for pet in pets\n if pet.is_available()\n ],\n \"young_pet_count\": len(young_pet_names(pets, max_age)),\n }\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_summary_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nassert summary == {\n \"total_pets\": 3,\n \"available_labels\": [\"Milo\", \"Pepper (foster)\"],\n \"young_pet_count\": 2,\n}\n\nprint(\"summary tests passed\")\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"},"tests_check_adoption_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\n\npet = ShelterPet(\"Luna\", \"dog\", 5)\n\nassert pet.is_available() is True\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\n\nprint(\"adoption tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nassert summary == {\n \"total_pets\": 3,\n \"available_labels\": [\"Milo\", \"Pepper (foster)\"],\n \"young_pet_count\": 2,\n}\n\nprint(\"summary tests passed\")\n","checks":{"0":{"message":"Return all three shelter summary values so main.py prints the expected report."}},"expectedOutput":"summary tests passed","sourceChecks":{"0":{"message":"`build_summary` should reuse availability, polymorphic labels, and `young_pet_names()` rather than duplicating those rules."},"1":{"message":"Assert the complete summary produced by the supplied CSV-plus-adoption workflow."}}},"project_step_final_regression":{"title":"Milestone 6: finish the full regression suite","prompt":"Continue from the exact Milestone 5 workspace. Keep every earlier test file and completed production layer intact. In `tests/check_regression.py`, write one end-to-end regression check that loads the CSV, verifies row order and the FosterPet subtype, checks mixed `adoption_labels()` and `young_pet_names()` results, marks Luna adopted, verifies her availability changed, and asserts the final `build_summary()` dictionary. Keep the final `regression checks passed` print. Then finish `README.md` by explaining the responsibility of `models/`, `services/`, `storage/`, `tests/`, and `main.py`.","hint":"The final regression should call the real completed layers; do not recreate their logic inside the test.","help":{"concept":"A final regression test protects the whole workflow while the README records the responsibility boundary each folder owns.","hint_1":"Use `load_pets`, the reporting helpers, and the real adoption method.","hint_2":"Document responsibilities, not implementation trivia."},"starterCode":"# Added in Milestone 6.\n","starterFiles":{"main_py":{"content":"from services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nprint(summary[\"total_pets\"])\nprint(\", \".join(summary[\"available_labels\"]))\nprint(summary[\"young_pet_count\"])\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n self.adopted = True\n return self.adopted\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n return {\n \"total_pets\": len(pets),\n \"available_labels\": [\n pet.adoption_label()\n for pet in pets\n if pet.is_available()\n ],\n \"young_pet_count\": len(young_pet_names(pets, max_age)),\n }\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_regression_py":{"content":"# Added in Milestone 6.\n"},"README_md":{"content":"# Animal Shelter Quality Pass\n\nDocument the responsibility of `models/`, `services/`, `storage/`, `tests/`, and `main.py` in Milestone 6.\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"},"tests_check_adoption_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\n\npet = ShelterPet(\"Luna\", \"dog\", 5)\n\nassert pet.is_available() is True\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\n\nprint(\"adoption tests passed\")\n"},"tests_check_summary_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nassert summary == {\n \"total_pets\": 3,\n \"available_labels\": [\"Milo\", \"Pepper (foster)\"],\n \"young_pet_count\": 2,\n}\n\nprint(\"summary tests passed\")\n"}},"solutionFiles":{"main_py":{"content":"from services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nprint(summary[\"total_pets\"])\nprint(\", \".join(summary[\"available_labels\"]))\nprint(summary[\"young_pet_count\"])\n"},"models_shelter_pet_py":{"content":"class ShelterPet:\n def __init__(self, name, species, age):\n if age < 0:\n raise ValueError(\"age cannot be negative\")\n\n self.name = name\n self.species = species\n self.age = age\n self.adopted = False\n\n def is_available(self):\n return not self.adopted\n\n def adoption_label(self):\n return self.name\n\n def mark_adopted(self):\n self.adopted = True\n return self.adopted\n"},"services_reporting_py":{"content":"def adoption_labels(pets):\n return [pet.adoption_label() for pet in pets]\n\n\ndef young_pet_names(pets, max_age):\n return [pet.name for pet in pets if pet.age <= max_age]\n\n\ndef build_summary(pets, max_age):\n return {\n \"total_pets\": len(pets),\n \"available_labels\": [\n pet.adoption_label()\n for pet in pets\n if pet.is_available()\n ],\n \"young_pet_count\": len(young_pet_names(pets, max_age)),\n }\n"},"storage_pet_loader_py":{"content":"import csv\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\n\ndef load_pets(path):\n pets = []\n\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n pet_class = FosterPet if row[\"foster\"] == \"yes\" else ShelterPet\n pets.append(\n pet_class(\n row[\"name\"],\n row[\"species\"],\n int(row[\"age\"]),\n )\n )\n\n return pets\n"},"data_pets_csv":{"content":"name,species,age,foster\nMilo,cat,3,no\nLuna,dog,5,no\nPepper,rabbit,1,yes\n"},"tests_check_regression_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, build_summary, young_pet_names\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert isinstance(pets[2], FosterPet)\nassert adoption_labels(pets) == [\"Milo\", \"Luna\", \"Pepper (foster)\"]\nassert young_pet_names(pets, 3) == [\"Milo\", \"Pepper\"]\n\nassert pets[1].mark_adopted() is True\nassert pets[1].is_available() is False\n\nassert build_summary(pets, 3) == {\n \"total_pets\": 3,\n \"available_labels\": [\"Milo\", \"Pepper (foster)\"],\n \"young_pet_count\": 2,\n}\n\nprint(\"regression checks passed\")\n"},"README_md":{"content":"# Animal Shelter Quality Pass\n\n- `models/` owns pet state, validation, inheritance, and per-pet behavior.\n- `services/` coordinates collections and returns report data without printing.\n- `storage/` converts CSV rows into the correct model objects.\n- `tests/` protects model, service, loader, adoption-state, summary, and full-workflow behavior.\n- `main.py` is the thin runnable demonstration that wires the completed layers together.\n"},"models_foster_pet_py":{"content":"from models.shelter_pet import ShelterPet\n\n\nclass FosterPet(ShelterPet):\n def adoption_label(self):\n return f\"{self.name} (foster)\"\n"},"tests_check_model_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\n\npet = ShelterPet(\"Milo\", \"cat\", 3)\nfoster = FosterPet(\"Pepper\", \"rabbit\", 1)\n\nassert pet.name == \"Milo\"\nassert pet.species == \"cat\"\nassert pet.age == 3\nassert pet.is_available() is True\n\nassert isinstance(foster, ShelterPet)\nassert foster.adoption_label() == \"Pepper (foster)\"\n\ntry:\n ShelterPet(\"Broken\", \"dog\", -1)\n raise AssertionError(\"negative age should fail\")\nexcept ValueError:\n pass\n\nprint(\"model tests passed\")\n"},"tests_check_reporting_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, young_pet_names\n\nmixed = [\n ShelterPet(\"Milo\", \"cat\", 3),\n FosterPet(\"Pepper\", \"rabbit\", 1),\n]\n\nreverse_mixed = [\n FosterPet(\"Nova\", \"dog\", 4),\n ShelterPet(\"Rex\", \"dog\", 2),\n]\n\nassert adoption_labels(mixed) == [\"Milo\", \"Pepper (foster)\"]\nassert adoption_labels(reverse_mixed) == [\"Nova (foster)\", \"Rex\"]\nassert young_pet_names(mixed, 2) == [\"Pepper\"]\nassert young_pet_names(reverse_mixed, 2) == [\"Rex\"]\n\nprint(\"reporting tests passed\")\n"},"tests_check_loader_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom models.shelter_pet import ShelterPet\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert [pet.age for pet in pets] == [3, 5, 1]\nassert isinstance(pets[0], ShelterPet)\nassert isinstance(pets[1], ShelterPet)\nassert isinstance(pets[2], FosterPet)\nassert pets[2].adoption_label() == \"Pepper (foster)\"\n\nprint(\"loader tests passed\")\n"},"tests_check_adoption_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.shelter_pet import ShelterPet\n\npet = ShelterPet(\"Luna\", \"dog\", 5)\n\nassert pet.is_available() is True\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\nassert pet.mark_adopted() is True\nassert pet.is_available() is False\n\nprint(\"adoption tests passed\")\n"},"tests_check_summary_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom services.reporting import build_summary\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\npets[1].mark_adopted()\n\nsummary = build_summary(pets, 3)\n\nassert summary == {\n \"total_pets\": 3,\n \"available_labels\": [\"Milo\", \"Pepper (foster)\"],\n \"young_pet_count\": 2,\n}\n\nprint(\"summary tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.foster_pet import FosterPet\nfrom services.reporting import adoption_labels, build_summary, young_pet_names\nfrom storage.pet_loader import load_pets\n\npets = load_pets(\"data/pets.csv\")\n\nassert [pet.name for pet in pets] == [\"Milo\", \"Luna\", \"Pepper\"]\nassert isinstance(pets[2], FosterPet)\nassert adoption_labels(pets) == [\"Milo\", \"Luna\", \"Pepper (foster)\"]\nassert young_pet_names(pets, 3) == [\"Milo\", \"Pepper\"]\n\nassert pets[1].mark_adopted() is True\nassert pets[1].is_available() is False\n\nassert build_summary(pets, 3) == {\n \"total_pets\": 3,\n \"available_labels\": [\"Milo\", \"Pepper (foster)\"],\n \"young_pet_count\": 2,\n}\n\nprint(\"regression checks passed\")\n","checks":{"0":{"message":"Keep the full shelter report and print the regression confirmation line."}},"expectedOutput":"regression checks passed","sourceChecks":{"0":{"message":"Exercise the real CSV loader, FosterPet subtype, and both reporting helpers in the final regression."},"1":{"message":"Protect the adoption transition and final summary in the end-to-end regression."},"2":{"message":"Explain the responsibility of models, services, storage, tests, and main.py in README.md."}}}}}},"refactoring-oop-services":{"label":"Refactoring OOP Services","summary":"Refactor working OOP code by moving list-wide coordination into focused services while keeping object-specific behavior on the model and main.py thin.","cards":{"sketch0":{"title":"Extract list-wide reporting"},"sketch1":{"title":"Keep model and service responsibilities separate"},"sketch2":{"title":"Refactor safely with imports and small steps"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_refactoring_oop_services_sketch0":{"title":"Extract a working report loop into ReportService","prompt":"`main.py` already works, and `models/book.py` already owns `Book.display_line()`. Refactor the list-wide report logic into `ReportService.build_report(self, books)` in `services/report_service.py`. The service must build the report from each Book's existing `display_line()` result and return the single newline-separated string. Then update `main.py` to import `ReportService`, remove the old report-building `for` loop, and print the value returned by `build_report(books)`. Preserve the same visible output.","hint":"Move the collection coordination, not the one-book formatting. `Book.display_line()` already owns that behavior.","help":{"concept":"A safe refactor moves list-wide work into the service while the model keeps its per-object behavior and the output stays stable.","hint_1":"The service can collect each `book.display_line()` result.","hint_2":"After the move, main.py should call the service instead of keeping the report loop."},"starterCode":"from models.book import Book\n\nfirst_title = input()\nfirst_price = int(input())\nsecond_title = input()\nsecond_price = int(input())\n\nbooks = [\n Book(first_title, first_price),\n Book(second_title, second_price),\n]\n\nlines = []\nfor book in books:\n lines.append(book.display_line())\n\nprint(\"\\n\".join(lines))\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\nfirst_title = input()\nfirst_price = int(input())\nsecond_title = input()\nsecond_price = int(input())\n\nbooks = [\n Book(first_title, first_price),\n Book(second_title, second_price),\n]\n\nlines = []\nfor book in books:\n lines.append(book.display_line())\n\nprint(\"\\n\".join(lines))\n"},"services_report_service_py":{"content":"class ReportService:\n def build_report(self, books):\n # Move the list-wide report coordination here.\n pass\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price\n\n def display_line(self):\n return f\"{self.title}: ${self.price}\"\n"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom services.report_service import ReportService\n\nfirst_title = input()\nfirst_price = int(input())\nsecond_title = input()\nsecond_price = int(input())\n\nbooks = [\n Book(first_title, first_price),\n Book(second_title, second_price),\n]\n\nprint(ReportService().build_report(books))\n"},"services_report_service_py":{"content":"class ReportService:\n def build_report(self, books):\n return \"\\n\".join(book.display_line() for book in books)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price\n\n def display_line(self):\n return f\"{self.title}: ${self.price}\"\n"}},"solutionCode":"from models.book import Book\nfrom services.report_service import ReportService\n\nfirst_title = input()\nfirst_price = int(input())\nsecond_title = input()\nsecond_price = int(input())\n\nbooks = [\n Book(first_title, first_price),\n Book(second_title, second_price),\n]\n\nprint(ReportService().build_report(books))\n","checks":{"0":{"message":"Define ReportService in its service file."},"1":{"message":"Return both formatted lines."}},"expectedOutput":"Python Basics: $12\nDebugging Guide: $18","sourceChecks":{"0":{"message":"Import `ReportService` from `services.report_service` after moving the report responsibility."},"1":{"message":"Remove the old collection loop from main.py and print the report returned by `ReportService.build_report(books)`."},"2":{"message":"`build_report(self, books)` should coordinate the collection using each Book's existing `display_line()` behavior."}}},"try_refactoring_oop_services_sketch1":{"title":"Move collection filtering into CatalogService","prompt":"`main.py` already works, and `Book.is_affordable(max_price)` already owns the one-book affordability rule. Refactor the list-wide filtering into `CatalogService.affordable_titles(self, books, max_price)` in `services/catalog_service.py`. The service must use each Book's existing `is_affordable(max_price)` method and return the matching titles in input order. Then update `main.py` to import and call `CatalogService`, remove the old filtering `for` loop, and keep printing the returned titles joined with ` | `. Preserve the same visible behavior.","hint":"The model decides whether one book is affordable; the service decides which titles to collect from the whole list.","help":{"concept":"A focused service coordinates a collection without stealing the object-specific rule from the model.","hint_1":"Call `book.is_affordable(max_price)` inside the service.","hint_2":"main.py should only create books, call the service, and display the returned titles."},"starterCode":"from models.book import Book\n\nmax_price = int(input())\n\nbooks = [\n Book(input(), int(input())),\n Book(input(), int(input())),\n Book(input(), int(input())),\n]\n\ntitles = []\nfor book in books:\n if book.is_affordable(max_price):\n titles.append(book.title)\n\nprint(\" | \".join(titles))\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\nmax_price = int(input())\n\nbooks = [\n Book(input(), int(input())),\n Book(input(), int(input())),\n Book(input(), int(input())),\n]\n\ntitles = []\nfor book in books:\n if book.is_affordable(max_price):\n titles.append(book.title)\n\nprint(\" | \".join(titles))\n"},"services_catalog_service_py":{"content":"class CatalogService:\n def affordable_titles(self, books, max_price):\n # Move the list-wide filtering coordination here.\n pass\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price\n\n def is_affordable(self, max_price):\n return self.price <= max_price\n"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom services.catalog_service import CatalogService\n\nmax_price = int(input())\n\nbooks = [\n Book(input(), int(input())),\n Book(input(), int(input())),\n Book(input(), int(input())),\n]\n\ntitles = CatalogService().affordable_titles(books, max_price)\nprint(\" | \".join(titles))\n"},"services_catalog_service_py":{"content":"class CatalogService:\n def affordable_titles(self, books, max_price):\n titles = []\n\n for book in books:\n if book.is_affordable(max_price):\n titles.append(book.title)\n\n return titles\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price\n\n def is_affordable(self, max_price):\n return self.price <= max_price\n"}},"solutionCode":"from models.book import Book\nfrom services.catalog_service import CatalogService\n\nmax_price = int(input())\n\nbooks = [\n Book(input(), int(input())),\n Book(input(), int(input())),\n Book(input(), int(input())),\n]\n\ntitles = CatalogService().affordable_titles(books, max_price)\nprint(\" | \".join(titles))\n","checks":{"0":{"message":"Define CatalogService in the service file."},"1":{"message":"Return the correct total for a list of book dictionaries."},"2":{"message":"Print the returned total from main.py."}},"expectedOutput":"Dune | Beloved","sourceChecks":{"0":{"message":"Import `CatalogService` from `services.catalog_service` after moving the collection filtering responsibility."},"1":{"message":"Remove the filtering loop from main.py and get `titles` from `CatalogService.affordable_titles(books, max_price)`."},"2":{"message":"`affordable_titles` should coordinate the collection by using each Book's existing `is_affordable(max_price)` rule."}}},"try_refactoring_oop_services_sketch2":{"title":"Refactor counting into a service method","prompt":"Complete `CatalogService.count_books(books)` so it returns the number of book dictionaries, including `0` for an empty list.","hint":"Return `len(books)`.","help":{"concept":"A small service method can still make responsibilities explicit and easy to test.","hint_1":"Return `len(books)`.","hint_2":"Inspect the requested file and account for each requirement before running the workspace."},"starterCode":"# Run this provided non-empty and empty-list demo.\nfrom services.catalog_service import CatalogService\n\nservice = CatalogService()\nprint(service.count_books([{\"title\": \"Dune\"}, {\"title\": \"Beloved\"}]))\nprint(service.count_books([]))\n","starterFiles":{"main_py":{"content":"# Run this provided non-empty and empty-list demo.\nfrom services.catalog_service import CatalogService\n\nservice = CatalogService()\nprint(service.count_books([{\"title\": \"Dune\"}, {\"title\": \"Beloved\"}]))\nprint(service.count_books([]))\n"},"services_catalog_service_py":{"content":"class CatalogService:\n def count_books(self, books):\n # TODO: return how many book dictionaries were supplied.\n pass\n"}},"solutionFiles":{"main_py":{"content":"from services.catalog_service import CatalogService\n\nservice = CatalogService()\nprint(service.count_books([{\"title\": \"Dune\"}, {\"title\": \"Beloved\"}]))\nprint(service.count_books([]))\n"},"services_catalog_service_py":{"content":"class CatalogService:\n def count_books(self, books):\n return len(books)\n"}},"solutionCode":"from services.catalog_service import CatalogService\n\nservice = CatalogService()\nprint(service.count_books([{\"title\": \"Dune\"}, {\"title\": \"Beloved\"}]))\nprint(service.count_books([]))\n","checks":{"0":{"message":"Return 2 for the provided two-book list."},"1":{"message":"Return 0 for an empty list."},"2":{"message":"Print both results from main.py."}},"expectedOutput":"2\n0"}},"practice":{"mc-refactor-benefits":{"title":"Recognize a successful refactor","prompt":"Which TWO outcomes show that moving report logic from `main.py` into a service was a useful refactor?","hint":"The responsibility should move while observable behavior stays stable.","help":{"concept":"Refactoring changes structure without changing the program's promised behavior.","hint_1":"The old output should still be produced.","hint_2":"The collection-wide responsibility should have one clear home."},"options":{"a":"main.py becomes thinner because the collection-wide report logic lives in a service","b":"The refactor changes the report format at the same time","c":"The same input still produces the same visible report","d":"The old loop remains duplicated in main.py and the service"}},"fb-service-home":{"title":"Choose the right home for report logic","prompt":"Complete the sentence with the best word.","hint":"The blank should name the file role that coordinates multiple objects.","help":{"concept":"List-wide orchestration and reporting usually belong in a service module rather than in one model object or scattered main.py code.","hint_1":"Think about the module that combines data from several objects.","hint_2":"The correct choice is the layer that builds reports and totals from object lists."},"template":"Catalog-wide report formatting usually belongs in a [blank1] module.","choices":["service","model","attribute","fixture"]},"ci-refactor-discount-service":{"title":"Create a pricing service method","prompt":"The catalog app now needs a separate pricing service. Complete `PricingService.discounted_total(books, percent)` in `services/pricing_service.py`. It should add all book prices, apply the percentage discount to the total, and return the discounted amount. For example, a 10 percent discount on a total of 50 should return 45.0.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom services.pricing_service import PricingService\n\nbooks = [Book(\"Python Basics\", 20), Book(\"Debugging Guide\", 30)]\nservice = PricingService()\nprint(service.discounted_total(books, 10))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom services.pricing_service import PricingService\n\nbooks = [Book(\"Python Basics\", 20), Book(\"Debugging Guide\", 30)]\nservice = PricingService()\nprint(service.discounted_total(books, 10))"},"services_pricing_service_py":{"content":"class PricingService:\n def discounted_total(self, books, percent):\n pass"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom services.pricing_service import PricingService\n\nbooks = [Book(\"Python Basics\", 20), Book(\"Debugging Guide\", 30)]\nservice = PricingService()\nprint(service.discounted_total(books, 10))"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price"},"services_pricing_service_py":{"content":"class PricingService:\n def discounted_total(self, books, percent):\n total = sum(book.price for book in books)\n return total * (1 - percent / 100)"}},"solutionCode":"from models.book import Book\nfrom services.pricing_service import PricingService\n\nbooks = [Book(\"Python Basics\", 20), Book(\"Debugging Guide\", 30)]\nservice = PricingService()\nprint(service.discounted_total(books, 10))","checks":{"0":{"message":"Define a PricingService class in services/pricing_service.py."},"1":{"message":"PricingService should be constructible with no arguments."},"2":{"message":"discounted_total should apply the percentage discount to the full total."},"3":{"message":"discounted_total should work with a different total and discount percent."}}},"mc-safe-refactor-steps":{"title":"Choose safe refactoring steps","prompt":"Which THREE actions make an OOP service refactor safer?","hint":"Move one responsibility, reconnect the caller, and verify behavior.","help":{"concept":"Small structural moves are safer when imports/calls are updated and behavior is checked after the move.","hint_1":"Do not mix unrelated behavior changes into the same refactor.","hint_2":"Keep a way to compare before and after behavior."},"options":{"a":"Move one collection-wide responsibility at a time","b":"Update the caller to import and use the new service","c":"Change output rules during the same refactor","d":"Run the program or tests again after the move"}},"fb-import-line":{"title":"Complete the service import","prompt":"Fill in the missing module name for this refactor.","hint":"The class lives in the `services` folder and the file name matches the service role.","help":{"concept":"After moving logic into a service file, the caller must import the class from the correct module path.","hint_1":"The import starts with `from services.` because the file is inside the services folder.","hint_2":"Use the module name that would hold `ReportService` in a file named after the service."},"template":"from services.[blank1] import ReportService","choices":["report_service","book","main","catalog"]},"ci-refactor-summary-service":{"title":"Build a one-line catalog summary service","prompt":"Complete `SummaryService.build_summary(books)` in `services/summary_service.py`. It should return a single string in this exact format: `Books: | Total: $`. For example, two books priced 12 and 18 should produce `Books: 2 | Total: $30`. This combines two pieces of orchestration logic in one service method.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom services.summary_service import SummaryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18)]\nservice = SummaryService()\nprint(service.build_summary(books))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom services.summary_service import SummaryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18)]\nservice = SummaryService()\nprint(service.build_summary(books))"},"services_summary_service_py":{"content":"class SummaryService:\n def build_summary(self, books):\n pass"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom services.summary_service import SummaryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18)]\nservice = SummaryService()\nprint(service.build_summary(books))"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price"},"services_summary_service_py":{"content":"class SummaryService:\n def build_summary(self, books):\n total = sum(book.price for book in books)\n return f\"Books: {len(books)} | Total: ${total}\""}},"solutionCode":"from models.book import Book\nfrom services.summary_service import SummaryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18)]\nservice = SummaryService()\nprint(service.build_summary(books))","checks":{"0":{"message":"Define a SummaryService class in services/summary_service.py."},"1":{"message":"SummaryService should be constructible with no arguments."},"2":{"message":"build_summary should return the exact summary format for the catalog."},"3":{"message":"build_summary should work for a one-book catalog."}}},"sc-main-role":{"title":"Keep main.py thin","prompt":"After list-wide filtering and reporting move into services, what should `main.py` mainly do?","hint":"Think about wiring pieces together rather than owning their internal logic.","help":{"concept":"The entry script should mainly create objects, call services, and display returned results.","hint_1":"Models and services should own the reusable behavior.","hint_2":"main.py is the coordinator at the application boundary."},"options":{"a":"Create objects, call service methods, and display returned results","b":"Keep duplicate copies of every service loop as a backup","c":"Move one-book methods out of the model and into print statements","d":"Avoid imports by keeping every responsibility in main.py"}},"dr-refactor-order":{"title":"Order the refactor steps","prompt":"Put these steps in a sensible order for moving report logic from `main.py` into a service file while preserving behavior.","hint":"Start by identifying the logic to move, then create the service, then reconnect the caller.","help":{"concept":"A safe refactor follows a sequence: isolate one responsibility, move it, reconnect imports and calls, then verify behavior.","hint_1":"The caller cannot use the new service until the service method exists.","hint_2":"After updating `main.py`, the last step is to run the app or tests and compare behavior."},"tokens":{"t1":"Identify the report-building code in main.py.","t2":"Create a service method for that logic.","t3":"Update main.py to import and call the service.","t4":"Run the program or tests to confirm the output stayed the same."}},"ci-refactor-filter-service":{"title":"Move filtering logic into InventoryService","prompt":"A catalog screen should show only affordable books. Complete `InventoryService.affordable_titles(books, max_price)` in `services/inventory_service.py`. Return a list of titles for every book whose price is less than or equal to `max_price`. This refactor moves filtering logic for a whole list into a service.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom services.inventory_service import InventoryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18), Book(\"Testing Notes\", 10)]\nservice = InventoryService()\nprint(service.affordable_titles(books, 12))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom services.inventory_service import InventoryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18), Book(\"Testing Notes\", 10)]\nservice = InventoryService()\nprint(service.affordable_titles(books, 12))"},"services_inventory_service_py":{"content":"class InventoryService:\n def affordable_titles(self, books, max_price):\n pass"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom services.inventory_service import InventoryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18), Book(\"Testing Notes\", 10)]\nservice = InventoryService()\nprint(service.affordable_titles(books, 12))"},"models_book_py":{"content":"class Book:\n def __init__(self, title, price):\n self.title = title\n self.price = price"},"services_inventory_service_py":{"content":"class InventoryService:\n def affordable_titles(self, books, max_price):\n return [book.title for book in books if book.price <= max_price]"}},"solutionCode":"from models.book import Book\nfrom services.inventory_service import InventoryService\n\nbooks = [Book(\"Python Basics\", 12), Book(\"Debugging Guide\", 18), Book(\"Testing Notes\", 10)]\nservice = InventoryService()\nprint(service.affordable_titles(books, 12))","checks":{"0":{"message":"Define an InventoryService class in services/inventory_service.py."},"1":{"message":"InventoryService should be constructible with no arguments."},"2":{"message":"affordable_titles should return titles whose prices are at or below the limit."},"3":{"message":"affordable_titles should return an empty list when nothing matches."}}}}},"testing-inheritance-and-polymorphism":{"label":"Testing Inheritance and Polymorphism","summary":"Write regression tests for subclass contracts and mixed-object services without rebuilding the production classes.","cards":{"sketch0":{"title":"Test a subclass contract"},"sketch1":{"title":"Test a mixed polymorphic service"},"sketch2":{"title":"Test a defensive edge case"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_testing_inheritance_and_polymorphism_sketch0":{"title":"Write a subclass contract test","prompt":"`CatalogItem` and `Book` are already complete. In `tests/check_book.py`, use the existing `book` fixture to assert that it is an instance of `CatalogItem`, then assert that `book.label()` returns exactly `Book: Dune by Frank Herbert`. Leave both model files unchanged and keep the final `book inheritance tests passed` print.","hint":"One assertion checks the inheritance relationship; the other checks the subclass's specialized public behavior.","help":{"concept":"A useful subclass regression test checks the relationship and the public contract without inspecting implementation details.","hint_1":"Use `isinstance(book, CatalogItem)`.","hint_2":"Assert the exact value returned by `book.label()`."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.catalog_item import CatalogItem\nfrom models.book import Book\n\nbook = Book(\"Dune\", \"Frank Herbert\")\n\n# Assert that book is a CatalogItem.\n# Assert that Book's specialized label() returns:\n# Book: Dune by Frank Herbert\n\nprint(\"book inheritance tests passed\")\n","starterFiles":{"tests_check_book_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.catalog_item import CatalogItem\nfrom models.book import Book\n\nbook = Book(\"Dune\", \"Frank Herbert\")\n\n# Assert that book is a CatalogItem.\n# Assert that Book's specialized label() returns:\n# Book: Dune by Frank Herbert\n\nprint(\"book inheritance tests passed\")\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def label(self):\n raise NotImplementedError(\"Subclasses must implement label().\")\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n self.title = title\n self.author = author\n\n def label(self):\n return f\"Book: {self.title} by {self.author}\"\n"}},"solutionFiles":{"tests_check_book_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.catalog_item import CatalogItem\nfrom models.book import Book\n\nbook = Book(\"Dune\", \"Frank Herbert\")\n\nassert isinstance(book, CatalogItem)\nassert book.label() == \"Book: Dune by Frank Herbert\"\n\nprint(\"book inheritance tests passed\")\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def label(self):\n raise NotImplementedError(\"Subclasses must implement label().\")\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n self.title = title\n self.author = author\n\n def label(self):\n return f\"Book: {self.title} by {self.author}\"\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.catalog_item import CatalogItem\nfrom models.book import Book\n\nbook = Book(\"Dune\", \"Frank Herbert\")\n\nassert isinstance(book, CatalogItem)\nassert book.label() == \"Book: Dune by Frank Herbert\"\n\nprint(\"book inheritance tests passed\")\n","checks":{"0":{"message":"build_book_label() should return the Book label from the subclass override."},"1":{"message":"Keep the success message print after the assertion passes."}},"expectedOutput":"book inheritance tests passed","sourceChecks":{"0":{"message":"Assert that the Book fixture is also a CatalogItem."},"1":{"message":"Assert the exact specialized value returned by `book.label()`."}}},"try_testing_inheritance_and_polymorphism_sketch1":{"title":"Write mixed-service regression tests","prompt":"`Book`, `Game`, and `build_labels(items)` are already complete. In `tests/check_catalog_report.py`, use the provided `mixed_items` fixture to assert the normal Book/Game labels in order. Then use the provided `edge_items` fixture to assert `Game: Untitled on Switch` followed by `Book: Beloved by Toni Morrison`. Do not rewrite the models or service. Keep the final `polymorphic report tests passed` print.","hint":"Call the service on each provided mixed fixture and compare the returned list with the exact expected labels.","help":{"concept":"A polymorphic service test passes representative mixed objects through the service and checks observable results.","hint_1":"The first assertion uses `mixed_items`.","hint_2":"The second assertion retrieves the empty-title edge case through `edge_items`."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\nfrom models.game import Game\nfrom services.catalog_report import build_labels\n\nmixed_items = [\n Book(\"Dune\", \"Frank Herbert\"),\n Game(\"Portal 2\", \"PC\"),\n]\n\nedge_items = [\n Game(\"\", \"Switch\"),\n Book(\"Beloved\", \"Toni Morrison\"),\n]\n\n# Assert build_labels(mixed_items) returns the two normal labels in order.\n# Assert build_labels(edge_items) returns:\n# Game: Untitled on Switch\n# Book: Beloved by Toni Morrison\n\nprint(\"polymorphic report tests passed\")\n","starterFiles":{"main_py":{"content":"# TODO: complete this step in main.py.\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n self.title = title\n self.author = author\n\n def label(self):\n return f\"Book: {self.title} by {self.author}\"\n"},"models_game_py":{"content":"class Game:\n def __init__(self, title, platform):\n self.title = title if title else \"Untitled\"\n self.platform = platform\n\n def label(self):\n return f\"Game: {self.title} on {self.platform}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n for item in items:\n labels.append(item.label())\n return labels\n"},"tests_check_catalog_report_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\nfrom models.game import Game\nfrom services.catalog_report import build_labels\n\nmixed_items = [\n Book(\"Dune\", \"Frank Herbert\"),\n Game(\"Portal 2\", \"PC\"),\n]\n\nedge_items = [\n Game(\"\", \"Switch\"),\n Book(\"Beloved\", \"Toni Morrison\"),\n]\n\n# Assert build_labels(mixed_items) returns the two normal labels in order.\n# Assert build_labels(edge_items) returns:\n# Game: Untitled on Switch\n# Book: Beloved by Toni Morrison\n\nprint(\"polymorphic report tests passed\")\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def label(self):\n raise NotImplementedError(\"Subclasses must implement label().\")\n"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.game import Game\nfrom services.catalog_report import build_labels\n\n\ndef build_sample_labels():\n items = [\n Book(\"Dune\", \"Frank Herbert\"),\n Game(\"Portal 2\", \"PC\"),\n ]\n return build_labels(items)\n\n\nprint(build_sample_labels())"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n self.title = title\n self.author = author\n\n def label(self):\n return f\"Book: {self.title} by {self.author}\"\n"},"models_game_py":{"content":"class Game:\n def __init__(self, title, platform):\n self.title = title if title else \"Untitled\"\n self.platform = platform\n\n def label(self):\n return f\"Game: {self.title} on {self.platform}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n for item in items:\n labels.append(item.label())\n return labels\n"},"tests_check_catalog_report_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\nfrom models.game import Game\nfrom services.catalog_report import build_labels\n\nmixed_items = [\n Book(\"Dune\", \"Frank Herbert\"),\n Game(\"Portal 2\", \"PC\"),\n]\n\nedge_items = [\n Game(\"\", \"Switch\"),\n Book(\"Beloved\", \"Toni Morrison\"),\n]\n\nassert build_labels(mixed_items) == [\n \"Book: Dune by Frank Herbert\",\n \"Game: Portal 2 on PC\",\n]\n\nassert build_labels(edge_items) == [\n \"Game: Untitled on Switch\",\n \"Book: Beloved by Toni Morrison\",\n]\n\nprint(\"polymorphic report tests passed\")\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def label(self):\n raise NotImplementedError(\"Subclasses must implement label().\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\nfrom models.game import Game\nfrom services.catalog_report import build_labels\n\nmixed_items = [\n Book(\"Dune\", \"Frank Herbert\"),\n Game(\"Portal 2\", \"PC\"),\n]\n\nedge_items = [\n Game(\"\", \"Switch\"),\n Book(\"Beloved\", \"Toni Morrison\"),\n]\n\nassert build_labels(mixed_items) == [\n \"Book: Dune by Frank Herbert\",\n \"Game: Portal 2 on PC\",\n]\n\nassert build_labels(edge_items) == [\n \"Game: Untitled on Switch\",\n \"Book: Beloved by Toni Morrison\",\n]\n\nprint(\"polymorphic report tests passed\")\n","checks":{"0":{"message":"build_sample_labels() should return labels from a mixed Book/Game list in order."},"1":{"message":"Print the returned label list."}},"expectedOutput":"polymorphic report tests passed","sourceChecks":{"0":{"message":"Assert the exact ordered labels returned for `mixed_items`."},"1":{"message":"Assert the exact ordered labels returned for `edge_items`."}}},"try_testing_inheritance_and_polymorphism_sketch2":{"title":"Test validation with a fixture edge case","prompt":"Practice an edge case. Complete `build_empty_title_label()` so a game with an empty title falls back to `Untitled` and returns `Game: Untitled on Switch`.","hint":"Replace an empty incoming title before the label method uses it.","help":{"concept":"A good test includes edge cases. Here, the subclass should still return a useful label when the title is missing.","hint_1":"In `__init__`, use a fallback like `\"Untitled\"` when the incoming title is empty.","hint_2":"Leave `label()` using the stored `self.title` so the validation change shows up automatically."},"starterCode":"# TODO: complete this step in main.py.\n","starterFiles":{"main_py":{"content":"# TODO: complete this step in main.py.\n"},"models_game_py":{"content":"class Game:\n def __init__(self, title, platform):\n # Replace an empty title with \"Untitled\".\n self.title = title\n self.platform = platform\n\n def label(self):\n return f\"Game: {self.title} on {self.platform}\""}},"solutionFiles":{"main_py":{"content":"from models.game import Game\n\n\ndef build_empty_title_label():\n game = Game(\"\", \"Switch\")\n return game.label()\n\n\nprint(build_empty_title_label())"},"models_game_py":{"content":"class Game:\n def __init__(self, title, platform):\n self.title = title if title else \"Untitled\"\n self.platform = platform\n\n def label(self):\n return f\"Game: {self.title} on {self.platform}\""}},"solutionCode":"from models.game import Game\n\n\ndef build_empty_title_label():\n game = Game(\"\", \"Switch\")\n return game.label()\n\n\nprint(build_empty_title_label())","checks":{"0":{"message":"build_empty_title_label() should prove the empty title is sanitized before labeling."},"1":{"message":"Print the sanitized label for the game."}}}},"practice":{"policy_single_choice_1":{"title":"Choose a useful subclass regression test","prompt":"Which assertion best checks the specialized public contract of `Book.label()`?","hint":"Test the result callers depend on.","help":{"concept":"A regression test should assert observable subclass behavior, not reimplement or inspect the method body.","hint_1":"Call the public method.","hint_2":"Compare its return value with the promised result."},"options":{"a":"`assert Book.__name__ == \"Book\"`","b":"`assert Book(\"Dune\", \"Frank Herbert\").label() == \"Book: Dune by Frank Herbert\"`","c":"`assert True`","d":"`assert \"label\" in open(\"models/book.py\").read()`"}},"policy_multi_choice_1":{"title":"Choose strong polymorphic-service fixtures","prompt":"Which TWO tests add meaningful coverage for a service that calls `label()` on a mixed collection?","hint":"Choose tests that exercise actual mixed objects and observable results.","help":{"concept":"Useful polymorphic tests vary the concrete objects or relevant edge cases while checking the shared service result.","hint_1":"A normal mixed Book/Game list is useful.","hint_2":"An edge-case object inside a mixed list adds different coverage."},"options":{"a":"Assert the labels from a mixed Book/Game list in order.","b":"Assert only that the service function's name is `build_labels`.","c":"Assert a mixed list containing a Game with an empty title uses its documented fallback.","d":"Assert `True` after importing the service."}},"policy_drag_reorder_1":{"title":"Order the inheritance test steps","prompt":"Put these steps in a sensible order for testing subclass behavior.","hint":"Start by creating the object, then call the method, then compare the result.","help":{"concept":"A clean inheritance test creates a concrete subclass object, calls the shared method, and then checks the returned value.","hint_1":"The object must exist before you can call the method.","hint_2":"You compare the returned label after the method call."},"tokens":{"t1":"Create a `Book` object","t2":"Call `book.label()`","t3":"Compare the returned string with the expected label"}},"policy_fill_blank_choice_1":{"title":"Name the shared behavior under test","prompt":"Complete the shared method name that both Book and Game objects provide to the report service.","hint":"It is the method the service calls on every object.","help":{"concept":"The shared public method is the contract the mixed-object service depends on.","hint_1":"Book and Game both expose the same method name.","hint_2":"The report service collects each object's label."},"template":"item.[blank1]()","choices":["label","book_label","game_label","__class__"]},"policy_code_input_3":{"title":"Print whether a number is negative","prompt":"Read one integer. Print `True` when the number is less than 0 and `False` otherwise.","hint":"Compare the value with zero.","help":{"concept":"A less-than comparison can detect negative numbers.","hint_1":"Use < 0 inside an if statement.","hint_2":"Print False for zero or positive values."},"starterCode":"n = int(input())\n# Your code here","solutionCode":"n = int(input())\nif n < 0:\n print(True)\nelse:\n print(False)"},"practice-test-inherited-method":{"title":"Make an inherited method pass its test","prompt":"The test expects a `Book` object to inherit `label()` from `Item`. Complete the base `label()` method so the assertion passes, then keep the final `tests passed` output.","hint":"The shared method should return `Item: ` using the stored title.","help":{"concept":"A focused test can verify that a subclass correctly receives shared behavior from its base class.","hint_1":"The shared method should return `Item: <title>` using the stored title.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n pass\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n","starterFiles":{"main_py":{"content":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n pass\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n"}},"solutionCode":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Item: {self.title}\"\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n","solutionFiles":{"main_py":{"content":"class Item:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Item: {self.title}\"\n\nclass Book(Item):\n pass\n\nbook = Book(\"Dune\")\nassert book.label() == \"Item: Dune\"\nprint(\"tests passed\")\n"}}},"practice-test-polymorphic-sounds":{"title":"Make a polymorphic collection test pass","prompt":"Complete `collect_sounds(animals)` so it calls `speak()` on every object and returns the resulting list. The provided `Cat` and `Dog` classes override `speak()`. Keep the assertion and final `tests passed` output.","hint":"Loop through the mixed objects and append `animal.speak()` for each one.","help":{"concept":"A polymorphism test checks common behavior through the shared method name instead of branching on each concrete class type.","hint_1":"Loop through the mixed objects and append `animal.speak()` for each one.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n # append each object's speak() result\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n","starterFiles":{"main_py":{"content":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n # append each object's speak() result\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n"}},"solutionCode":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n for animal in animals:\n sounds.append(animal.speak())\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n","solutionFiles":{"main_py":{"content":"class Animal:\n def speak(self):\n return \"?\"\n\nclass Cat(Animal):\n def speak(self):\n return \"meow\"\n\nclass Dog(Animal):\n def speak(self):\n return \"woof\"\n\ndef collect_sounds(animals):\n sounds = []\n for animal in animals:\n sounds.append(animal.speak())\n return sounds\n\nanimals = [Cat(), Dog(), Cat()]\nassert collect_sounds(animals) == [\"meow\", \"woof\", \"meow\"]\nprint(\"tests passed\")\n"}}}}},"testing-object-state":{"label":"Testing Object State","summary":"Write executable `assert` tests that prove starting state, rejected state changes, and repeated transitions on real objects.","cards":{"sketch0":{"title":"Assert state before and after a method call"},"sketch1":{"title":"Test both valid and rejected state"},"sketch2":{"title":"Test a sequence on the same object"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_testing_object_state_sketch0":{"title":"Write a before-and-after Book state test","prompt":"`models/book.py` is already complete. In `tests/check_book.py`, use the existing `book` object to write an assertion that it starts available, call `book.checkout()`, then write an assertion that the same object's `available` state is false. Leave the model file unchanged. The test script must still finish by printing `book state tests passed`.","hint":"Use `assert` for both observable states; the method call belongs between those two claims.","help":{"concept":"A state-change test proves the object's state before and after the mutating method.","hint_1":"Check `book.available` before `checkout()`.","hint_2":"Check the same attribute again after `checkout()`."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\n# Assert that the new book starts available.\n# Call checkout() on this same book.\n# Assert that the same book is now unavailable.\n\nprint(\"book state tests passed\")\n","starterFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n"},"tests_check_book_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\n# Assert that the new book starts available.\n# Call checkout() on this same book.\n# Assert that the same book is now unavailable.\n\nprint(\"book state tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\nassert book.available is True\nbook.checkout()\nassert book.available is False\n\nprint(\"book state tests passed\")\n","checks":{"0":{"message":"Keep the Book class defined in models/book.py."},"1":{"message":"Book should still be constructible with a title."},"2":{"message":"A Book instance should have title and available attributes."},"3":{"message":"A new book should start available, then become unavailable after checkout()."}},"solutionFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n"},"tests_check_book_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.book import Book\n\nbook = Book(\"Dune\")\n\nassert book.available is True\nbook.checkout()\nassert book.available is False\n\nprint(\"book state tests passed\")\n"}},"expectedOutput":"book state tests passed","sourceChecks":{"0":{"message":"Use the same Book object for a starting-state assertion, `checkout()`, and an updated-state assertion."}}},"try_testing_object_state_sketch1":{"title":"Test both sides of a validation rule","prompt":"`models/task.py` is already complete. In `tests/check_task.py`, write one assertion proving the existing `normal_task` keeps priority `2`, and another proving the existing `invalid_task` normalizes priority `-5` to `0`. Leave the model unchanged. Keep the final `task validation tests passed` print.","hint":"A validation test set needs one accepted input and one rejected or corrected input.","help":{"concept":"Testing both branches distinguishes the validation rule from a constructor that simply stores every input unchanged.","hint_1":"The normal task should keep priority 2.","hint_2":"The invalid task should expose priority 0."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\n# Assert that the valid priority stays 2.\n# Assert that the negative priority becomes 0.\n\nprint(\"task validation tests passed\")\n","starterFiles":{"models_task_py":{"content":"class Task:\n def __init__(self, name, priority):\n self.name = name\n self.priority = priority if priority >= 0 else 0\n"},"tests_check_task_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\n# Assert that the valid priority stays 2.\n# Assert that the negative priority becomes 0.\n\nprint(\"task validation tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\nassert normal_task.priority == 2\nassert invalid_task.priority == 0\n\nprint(\"task validation tests passed\")\n","checks":{"0":{"message":"Keep the Task class defined in models/task.py."},"1":{"message":"A Task instance should store name and priority."},"2":{"message":"A normal priority should be stored unchanged."},"3":{"message":"A negative priority should be corrected to 0."}},"solutionFiles":{"models_task_py":{"content":"class Task:\n def __init__(self, name, priority):\n self.name = name\n self.priority = priority if priority >= 0 else 0\n"},"tests_check_task_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.task import Task\n\nnormal_task = Task(\"Email\", 2)\ninvalid_task = Task(\"Broken\", -5)\n\nassert normal_task.priority == 2\nassert invalid_task.priority == 0\n\nprint(\"task validation tests passed\")\n"}},"expectedOutput":"task validation tests passed","sourceChecks":{"0":{"message":"Assert that a Task created with priority 2 still has priority 2."},"1":{"message":"Assert that a Task created with priority -5 exposes priority 0."}}},"try_testing_object_state_sketch2":{"title":"Write a repeated state-transition test","prompt":"`models/counter.py` is already complete. In `tests/check_counter.py`, use the existing `counter` object to assert its count is `0`, call `increment()` and assert `1`, then call `increment()` again and assert `2`. Use the same object for the whole sequence. Leave the model unchanged and keep the final `counter sequence tests passed` print.","hint":"The important part is the sequence: 0 → increment → 1 → increment → 2 on one instance.","help":{"concept":"A repeated-transition test catches bugs that only appear after the same object changes state more than once.","hint_1":"Start with an assertion before any method call.","hint_2":"Assert again after each increment on the same counter."},"starterCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\n# Assert count starts at 0.\n# Increment the same counter and assert count is 1.\n# Increment the same counter again and assert count is 2.\n\nprint(\"counter sequence tests passed\")\n","starterFiles":{"models_counter_py":{"content":"class Counter:\n def __init__(self):\n self.count = 0\n\n def increment(self):\n self.count += 1\n"},"tests_check_counter_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\n# Assert count starts at 0.\n# Increment the same counter and assert count is 1.\n# Increment the same counter again and assert count is 2.\n\nprint(\"counter sequence tests passed\")\n"}},"solutionCode":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\nassert counter.count == 0\ncounter.increment()\nassert counter.count == 1\ncounter.increment()\nassert counter.count == 2\n\nprint(\"counter sequence tests passed\")\n","checks":{"0":{"message":"Keep the Counter class defined in models/counter.py."},"1":{"message":"A Counter instance should have a count attribute."},"2":{"message":"The count should move from 0 to 1 to 2 across two increment() calls."}},"solutionFiles":{"models_counter_py":{"content":"class Counter:\n def __init__(self):\n self.count = 0\n\n def increment(self):\n self.count += 1\n"},"tests_check_counter_py":{"content":"import sys\nsys.path.insert(0, \".\")\n\nfrom models.counter import Counter\n\ncounter = Counter()\n\nassert counter.count == 0\ncounter.increment()\nassert counter.count == 1\ncounter.increment()\nassert counter.count == 2\n\nprint(\"counter sequence tests passed\")\n"}},"expectedOutput":"counter sequence tests passed","sourceChecks":{"0":{"message":"Use the same Counter object to assert the full 0 → 1 → 2 state sequence."}}}},"practice":{"q-testing-object-state-single-1":{"title":"What should an object-state test check after a mutating method runs?","prompt":"A `checkout()` method is supposed to change a book from available to unavailable. Which test idea best proves that state change happened?","hint":"Look for the choice that checks the attribute after the method call, not just that the method exists.","help":{"concept":"A state-change test should verify the actual attribute value after a mutating method runs, because the goal is to prove behavior, not just structure.","hint_1":"A method can exist and still fail to update the object's data correctly.","hint_2":"Choose the option that inspects the `available` attribute after calling `checkout()`."},"options":{"a":"Create a Book object and check that `available` becomes `False` after calling `checkout()`","b":"Only check that the `Book` class has a `checkout` method name","c":"Print the object once and assume the method worked","d":"Check only the book title because constructors are more important than methods"}},"q-testing-object-state-multi-1":{"title":"Choose the strongest constructor validation checks","prompt":"A `Task` constructor should keep positive priorities unchanged and replace negative priorities with `0`. Which assertions belong in a good test set? Choose all that apply.","hint":"Include one check for valid input and one for invalid input.","help":{"concept":"Good validation coverage includes both the normal path and the edge-case path so the constructor rule is tested from more than one angle.","hint_1":"One correct option should confirm that a positive priority stays the same.","hint_2":"Another correct option should confirm that a negative priority does not remain negative after construction."},"options":{"a":"`Task(\"Email\", 2).priority == 2`","b":"`Task(\"Broken\", -5).priority == 0`","c":"`Task(\"Email\", 2).name == 2`","d":"`Task(\"Broken\", -5).priority == -5`"}},"q-testing-object-state-fill-1":{"title":"Complete an assert for starting state","prompt":"Fill in the missing value so the assertion checks that a new counter starts at zero.","hint":"A new `Counter` object should begin with no increments applied.","help":{"concept":"Starting-state assertions verify what the constructor sets before any methods change the object.","hint_1":"The `count` attribute should match the constructor's initial value.","hint_2":"Choose the numeric value that represents an untouched counter."},"template":"assert counter.count == [blank1]","choices":["0","1","False","None"]},"q-testing-object-state-drag-1":{"title":"Order a before-and-after state test","prompt":"Put these testing steps in the best order for checking a method that changes object state.","hint":"Read each piece and arrange them in the order the statement should be understood.","help":{"concept":"The pieces should form a valid statement in a logical order.","hint_1":"Start with the piece that introduces the idea or action.","hint_2":"Place dependent pieces after the part they describe or complete."},"tokens":{"t1":"Assert the starting attribute value","t2":"Create the object","t3":"Call the state-changing method","t4":"Assert the updated attribute value"}},"q-testing-object-state-multi-2":{"title":"Spot useful object-state edge cases","prompt":"You are testing a `Counter` object with an `increment()` method. Which checks help prove repeated state changes work correctly? Choose all that apply.","hint":"Think about what happens before any increments and after more than one increment.","help":{"concept":"Repeated state-change tests are stronger when they verify the initial state and multiple successive updates on the same object.","hint_1":"One correct option should check the starting count before any method calls.","hint_2":"Another correct option should check the count after the method has been called more than once on the same instance."},"options":{"a":"Assert that a new counter starts at `0`","b":"Assert that the same counter reaches `2` after two `increment()` calls","c":"Only check that `increment` is spelled correctly","d":"Create two separate counters and ignore their `count` values"}},"q-testing-object-state-fill-2":{"title":"Complete an assert after a checkout","prompt":"Fill in the missing value so the assertion checks the book's state after `checkout()` has already run.","hint":"After checkout, the book should no longer be available.","help":{"concept":"After-method assertions should match the new stored state, not the original constructor value.","hint_1":"The `available` attribute should switch away from its starting value.","hint_2":"Choose the boolean value that represents an unavailable book."},"template":"assert book.available is [blank1]","choices":["True","False","0","Lesson notes panel"]},"ci-testing-object-state-debug-book-return":{"title":"Fix a broken return method after state changes","prompt":"A checkout service uses `Book.checkout()` and `Book.return_book()`. Right now, returning a book does not restore availability. Fix `models/book.py` so the object's state changes correctly. Do not change the test file. When you click Run, the output panel should show that the tests passed.","hint":"Read the task \"Fix a broken return method after state changes\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Fix a broken return method after state changes\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = False","starterFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = False"},"tests_check_book_return_py":{"content":"from models.book import Book\n\nbook = Book(\"Dune\")\nassert book.available is True\nbook.checkout()\nassert book.available is False\nbook.return_book()\nassert book.available is True\n\nprint(\"book return tests passed\")"}},"solutionFiles":{"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = True"},"tests_check_book_return_py":{"content":"from models.book import Book\n\nbook = Book(\"Dune\")\nassert book.available is True\nbook.checkout()\nassert book.available is False\nbook.return_book()\nassert book.available is True\n\nprint(\"book return tests passed\")"}},"solutionCode":"class Book:\n def __init__(self, title):\n self.title = title\n self.available = True\n\n def checkout(self):\n self.available = False\n\n def return_book(self):\n self.available = True","checks":{"0":{"message":"Keep the Book class defined."},"1":{"message":"Book instances should still store title and available."},"2":{"message":"A new Book should start available."},"3":{"message":"checkout() should mark the book unavailable."},"4":{"message":"return_book() should make a checked-out book available again."}}},"ci-testing-object-state-fix-wallet-validation":{"title":"Fix wallet validation so balance never starts negative","prompt":"A budgeting app has a `Wallet` class in `models/wallet.py`. The constructor should store the given balance when it is zero or more, but negative starting balances should become `0`. The current code stores negative values by mistake. Fix the class so the provided tests in `tests/check_wallet.py` pass when you click Run.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = starting_balance","starterFiles":{"models_wallet_py":{"content":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = starting_balance"},"tests_check_wallet_py":{"content":"from models.wallet import Wallet\n\nwallet_a = Wallet(\"Ava\", 25)\nassert wallet_a.balance == 25\n\nwallet_b = Wallet(\"Ben\", -10)\nassert wallet_b.balance == 0\n\nprint(\"wallet validation tests passed\")"}},"solutionFiles":{"models_wallet_py":{"content":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = max(0, starting_balance)"},"tests_check_wallet_py":{"content":"from models.wallet import Wallet\n\nwallet_a = Wallet(\"Ava\", 25)\nassert wallet_a.balance == 25\n\nwallet_b = Wallet(\"Ben\", -10)\nassert wallet_b.balance == 0\n\nprint(\"wallet validation tests passed\")"}},"solutionCode":"class Wallet:\n def __init__(self, owner, starting_balance):\n self.owner = owner\n self.balance = max(0, starting_balance)","checks":{"0":{"message":"Keep the Wallet class defined."},"1":{"message":"Wallet instances should store owner and balance."},"2":{"message":"A valid starting balance should stay unchanged."},"3":{"message":"A negative starting balance should be corrected to 0."}}},"ci-testing-object-state-fix-scoreboard-add-points":{"title":"Fix a method that updates score incorrectly","prompt":"A game app has a `Scoreboard` class in `models/scoreboard.py`. The `add_points()` method should increase the current score by the amount passed in. Right now it resets the score instead. Fix the class so the tests in `tests/check_scoreboard.py` pass.","hint":"Read the task \"Fix a method that updates score incorrectly\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Fix a method that updates score incorrectly\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score = points","starterFiles":{"models_scoreboard_py":{"content":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score = points"},"tests_check_scoreboard_py":{"content":"from models.scoreboard import Scoreboard\n\nboard = Scoreboard()\nassert board.score == 0\nboard.add_points(5)\nassert board.score == 5\nboard.add_points(3)\nassert board.score == 8\n\nprint(\"scoreboard state tests passed\")"}},"solutionFiles":{"models_scoreboard_py":{"content":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score += points"},"tests_check_scoreboard_py":{"content":"from models.scoreboard import Scoreboard\n\nboard = Scoreboard()\nassert board.score == 0\nboard.add_points(5)\nassert board.score == 5\nboard.add_points(3)\nassert board.score == 8\n\nprint(\"scoreboard state tests passed\")"}},"solutionCode":"class Scoreboard:\n def __init__(self):\n self.score = 0\n\n def add_points(self, points):\n self.score += points","checks":{"0":{"message":"Keep the Scoreboard class defined."},"1":{"message":"Scoreboard instances should have a score attribute."},"2":{"message":"A new Scoreboard should start at 0."},"3":{"message":"After add_points(5), the score should be 5."},"4":{"message":"Points should accumulate, so 5 then 3 should produce 8."}}}}}},"python-11-oop-capstone-project":{"capstone-domain-model":{"label":"Capstone Domain Model","summary":"Build the task objects that carry the tracker domain before adding storage or reports.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_domain_model_sketch0":{"title":"Create the shared BaseTask model","prompt":"In `models/base_task.py`, implement `BaseTask` with `title`, validated `priority`, and `completed` state. New tasks start incomplete. `mark_done()` sets completed to True, `is_open()` returns the opposite, and `summary()` raises NotImplementedError. The supplied main.py marks one task done and prints its state.","hint":"Validate before storing the fields, then mutate only `self.completed` in mark_done().","help":{"concept":"The base class owns shared state and behavior while leaving the concrete summary format to subclasses.","hint_1":"Validate before storing the fields, then mutate only `self.completed` in mark_done().","hint_2":"Inspect the requested file and account for each requirement before running the workspace."},"starterCode":"# Run this provided BaseTask state demo.\nfrom models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n","starterFiles":{"main_py":{"content":"# Run this provided BaseTask state demo.\nfrom models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n"},"models_base_task_py":{"content":"class BaseTask:\n def __init__(self, title, priority=\"medium\", completed=False):\n # TODO: validate and store title, priority, and completed.\n pass\n\n def mark_done(self):\n # TODO: set completed to True and return it.\n pass\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"}},"solutionFiles":{"main_py":{"content":"from models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"}},"solutionCode":"from models.base_task import BaseTask\n\ntask = BaseTask(\"Draft roadmap\", \"high\")\ntask.mark_done()\nprint(task.title)\nprint(task.priority)\nprint(task.completed)\n","checks":{"0":{"message":"Store the shared task attributes."},"1":{"message":"A marked-done task should no longer be open."},"2":{"message":"Print the title, priority, and final completed state."}},"expectedOutput":"Draft roadmap\nhigh\nTrue"}}}},"capstone-scope-and-architecture":{"label":"Capstone Scope and Architecture","summary":"Plan the Smart Task Tracker workspace so models, services, data, and main.py each have a clear job.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_scope_and_architecture_sketch0":{"title":"Plan one clean capstone workspace","prompt":"Complete `reports/summary.py` so build_summary(tasks) returns one summary line per task. Keep the task hierarchy in models and the runner in main.py; do not copy model classes into main.py.","hint":"Join task.summary() results with newline characters.","help":{"concept":"A clean architecture gives models, reports, storage, services, and the runner separate responsibilities.","hint_1":"Join task.summary() results with newline characters.","hint_2":"Review the file path, class or function name, and output requirements together."},"starterCode":"# Run this provided architecture snapshot.\nfrom models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n","starterFiles":{"main_py":{"content":"# Run this provided architecture snapshot.\nfrom models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n"},"models_base_task_py":{"content":"# Starter guidance: Plan one clean capstone workspace. Follow the prompt and edit the requested code below.\nclass BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"# Starter guidance: Plan one clean capstone workspace. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"# Starter guidance: Plan one clean capstone workspace. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"# Keep this package marker so imports work.\nfrom models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"def build_summary(tasks):\n # TODO: return one summary line per task.\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"from models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"from models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"from models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"def build_summary(tasks):\n return \"\\n\".join(task.summary() for task in tasks)\n"}},"solutionCode":"from models import BugTask, FeatureTask\nfrom reports.summary import build_summary\n\ntasks = [BugTask(\"Fix login redirect\", \"high\", \"critical\"), FeatureTask(\"Add dark mode\", \"medium\", 3)]\nprint(build_summary(tasks))\n","checks":{"0":{"message":"Return both task summaries from the report module."}},"expectedOutput":"BUG: Fix login redirect | priority=high | severity=critical | done=False\nFEATURE: Add dark mode | priority=medium | points=3 | done=False"}}}},"capstone-storage-and-reports":{"label":"Capstone Storage and Reports","summary":"Load task data into objects and turn those objects into useful report output.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_storage_and_reports_sketch0":{"title":"Load task objects from CSV","prompt":"Complete storage/task_storage.py so load_tasks(path) reads data/tasks.csv and returns the correct task subclasses in file order. The supplied runner prints the count and first title.","hint":"Use DictReader, convert completed to bool, and convert feature detail to int.","help":{"concept":"Storage code translates serialized rows into validated domain objects.","hint_1":"Use DictReader, convert completed to bool, and convert feature detail to int.","hint_2":"Use the requested file boundary as part of the solution contract."},"starterCode":"# Run this provided storage smoke test.\nfrom storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n","starterFiles":{"main_py":{"content":"# Run this provided storage smoke test.\nfrom storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n"},"models_base_task_py":{"content":"# Starter guidance: Load task objects from CSV. Follow the prompt and edit the requested code below.\nclass BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"# Starter guidance: Load task objects from CSV. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"# Starter guidance: Load task objects from CSV. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"# Keep this package marker so imports work.\nfrom models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"},"storage_task_storage_py":{"content":"import csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n # TODO: parse each CSV row into the matching task subclass.\n pass\n"}},"solutionFiles":{"main_py":{"content":"from storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"from models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"from models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"from models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"},"storage_task_storage_py":{"content":"import csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n tasks = []\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n completed = row[\"completed\"].lower() == \"true\"\n if row[\"kind\"] == \"bug\":\n task = BugTask(row[\"title\"], row[\"priority\"], row[\"detail\"], completed)\n elif row[\"kind\"] == \"feature\":\n task = FeatureTask(row[\"title\"], row[\"priority\"], int(row[\"detail\"]), completed)\n else:\n raise ValueError(f\"unknown task kind: {row['kind']}\")\n tasks.append(task)\n return tasks\n"}},"solutionCode":"from storage.task_storage import load_tasks\n\ntasks = load_tasks(\"data/tasks.csv\")\nprint(len(tasks))\nprint(tasks[0].title)\n","checks":{"0":{"message":"Load three tasks and preserve the first title."}},"expectedOutput":"3\nFix login redirect"}}}},"capstone-tests-and-polish":{"label":"Capstone Tests and Polish","summary":"Add assertions, final output polish, and README handoff notes so the capstone feels complete.","cards":{"sketch0":{"title":"Planning brief"}},"finalCapstone":{"steps":{"try_capstone_tests_and_polish_sketch0":{"title":"Add focused model checks","prompt":"Complete main.py with assertions that a new BugTask is open and a FeatureTask estimate of 0 becomes 1. Print `model checks passed` after both assertions.","hint":"Create both objects, assert their state, then print confirmation.","help":{"concept":"Focused tests prove validation and starting state before testing larger workflows.","hint_1":"Create both objects, assert their state, then print confirmation.","hint_2":"Use the requested file boundary as part of the solution contract."},"starterCode":"# TODO: create the two tasks, add the required assertions, then print confirmation.\n","starterFiles":{"main_py":{"content":"# TODO: create the two tasks, add the required assertions, then print confirmation.\n"},"models_base_task_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nclass BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nfrom models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"# Keep this package marker so imports work.\nfrom models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\ndef build_summary(tasks):\n lines = [\"SMART TASK TRACKER\"]\n lines.extend(task.summary() for task in tasks)\n open_count = sum(task.is_open() for task in tasks)\n lines.append(f\"OPEN: {open_count} | DONE: {len(tasks) - open_count}\")\n return \"\\n\".join(lines)\n"},"storage_task_storage_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nimport csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n tasks = []\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n completed = row[\"completed\"].lower() == \"true\"\n if row[\"kind\"] == \"bug\":\n task = BugTask(row[\"title\"], row[\"priority\"], row[\"detail\"], completed)\n elif row[\"kind\"] == \"feature\":\n task = FeatureTask(row[\"title\"], row[\"priority\"], int(row[\"detail\"]), completed)\n else:\n raise ValueError(f\"unknown task kind: {row['kind']}\")\n tasks.append(task)\n return tasks\n"},"services_tracker_service_py":{"content":"# Starter guidance: Add focused model checks. Follow the prompt and edit the requested code below.\nclass TrackerService:\n def __init__(self, tasks=None):\n self.tasks = list(tasks or [])\n\n def add_task(self, task):\n self.tasks.append(task)\n return task\n\n def mark_done(self, title):\n for task in self.tasks:\n if task.title == title:\n task.mark_done()\n return True\n return False\n\n def count_open_tasks(self):\n return sum(task.is_open() for task in self.tasks)\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"}},"solutionFiles":{"main_py":{"content":"from models import BugTask, FeatureTask\n\nbug = BugTask(\"Fix login\", \"high\", \"critical\")\nfeature = FeatureTask(\"Polish UI\", \"low\", 0)\nassert bug.is_open() is True\nassert feature.estimate_points == 1\nprint(\"model checks passed\")\n"},"models_base_task_py":{"content":"class BaseTask:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, title, priority=\"medium\", completed=False):\n if not title.strip():\n raise ValueError(\"title is required\")\n if priority not in self.VALID_PRIORITIES:\n raise ValueError(\"priority must be low, medium, or high\")\n self.title = title\n self.priority = priority\n self.completed = bool(completed)\n\n def mark_done(self):\n self.completed = True\n return self.completed\n\n def is_open(self):\n return not self.completed\n\n def summary(self):\n raise NotImplementedError(\"Subclasses must implement summary()\")\n"},"models_bug_task_py":{"content":"from models.base_task import BaseTask\n\nclass BugTask(BaseTask):\n def __init__(self, title, priority, severity, completed=False):\n super().__init__(title, priority, completed)\n self.severity = severity\n\n def summary(self):\n return f\"BUG: {self.title} | priority={self.priority} | severity={self.severity} | done={self.completed}\"\n"},"models_feature_task_py":{"content":"from models.base_task import BaseTask\n\nclass FeatureTask(BaseTask):\n def __init__(self, title, priority, estimate_points, completed=False):\n super().__init__(title, priority, completed)\n self.estimate_points = max(1, int(estimate_points))\n\n def summary(self):\n return f\"FEATURE: {self.title} | priority={self.priority} | points={self.estimate_points} | done={self.completed}\"\n"},"models___init___py":{"content":"from models.base_task import BaseTask\nfrom models.bug_task import BugTask\nfrom models.feature_task import FeatureTask\n\n__all__ = [\"BaseTask\", \"BugTask\", \"FeatureTask\"]\n"},"reports_summary_py":{"content":"def build_summary(tasks):\n lines = [\"SMART TASK TRACKER\"]\n lines.extend(task.summary() for task in tasks)\n open_count = sum(task.is_open() for task in tasks)\n lines.append(f\"OPEN: {open_count} | DONE: {len(tasks) - open_count}\")\n return \"\\n\".join(lines)\n"},"storage_task_storage_py":{"content":"import csv\nfrom models import BugTask, FeatureTask\n\ndef load_tasks(path):\n tasks = []\n with open(path, newline=\"\") as file:\n for row in csv.DictReader(file):\n completed = row[\"completed\"].lower() == \"true\"\n if row[\"kind\"] == \"bug\":\n task = BugTask(row[\"title\"], row[\"priority\"], row[\"detail\"], completed)\n elif row[\"kind\"] == \"feature\":\n task = FeatureTask(row[\"title\"], row[\"priority\"], int(row[\"detail\"]), completed)\n else:\n raise ValueError(f\"unknown task kind: {row['kind']}\")\n tasks.append(task)\n return tasks\n"},"services_tracker_service_py":{"content":"class TrackerService:\n def __init__(self, tasks=None):\n self.tasks = list(tasks or [])\n\n def add_task(self, task):\n self.tasks.append(task)\n return task\n\n def mark_done(self, title):\n for task in self.tasks:\n if task.title == title:\n task.mark_done()\n return True\n return False\n\n def count_open_tasks(self):\n return sum(task.is_open() for task in self.tasks)\n"},"data_tasks_csv":{"content":"kind,title,priority,detail,completed\nbug,Fix login redirect,high,critical,false\nfeature,Add dark mode,medium,3,false\nfeature,Export CSV,low,5,true\n"}},"solutionCode":"from models import BugTask, FeatureTask\n\nbug = BugTask(\"Fix login\", \"high\", \"critical\")\nfeature = FeatureTask(\"Polish UI\", \"low\", 0)\nassert bug.is_open() is True\nassert feature.estimate_points == 1\nprint(\"model checks passed\")\n","checks":{"0":{"message":"Run both model assertions before confirmation."}},"expectedOutput":"model checks passed"}}}},"module-11-final-oop-capstone":{"label":"Neighborhood Pantry Request Coordinator","summary":"Build a pantry request coordinator that turns saved food and hygiene requests into validated objects, managed state, and a clear daily report.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Neighborhood Pantry Request Coordinator"}},"projectSteps":{"try_module_11_final_oop_capstone_sketch0":{"title":"Milestone 1: Build the abstract request foundation"},"project_pantry_request_step_2_models":{"title":"Milestone 2: Add HygieneRequest and prove polymorphism"},"project_pantry_request_step_3_service":{"title":"Milestone 3: Give PantryService ownership of the queue"},"project_pantry_request_step_4_storage":{"title":"Milestone 4: Load request objects from CSV"},"project_pantry_request_step_5_reports_tests":{"title":"Milestone 5: Add the report and regression tests"},"project_pantry_request_step_6_final_handoff":{"title":"Milestone 6: Deliver the final pantry coordinator"}},"finalCapstone":{"steps":{"try_module_11_final_oop_capstone_sketch0":{"title":"Milestone 1: Build the abstract request foundation","prompt":"Build the shared pantry-request foundation. In `models/pantry_request.py`, make `PantryRequest` inherit from `ABC`; keep the allowed priorities `low`, `medium`, and `high`; validate `household` and `priority` through properties; store fulfillment state privately; expose a read-only `fulfilled` property; implement `mark_fulfilled()` and `is_open()`; and make `category(self)` and `details(self)` abstract methods. `summary()` must remain concrete and build its text from those public members. In `models/food_request.py`, keep `FoodRequest(PantryRequest)`, call `super().__init__`, validate a nonblank `food_type`, return `FOOD` from `category()`, and return `food=<value>` from `details()`. Finally, complete `main.py` so it creates a FoodRequest from the provided inputs and prints its summary. Do not implement HygieneRequest yet.","hint":"Retrieve the validated-property pattern from Module 8 and the ABC/inheritance patterns from Module 9.","help":{"concept":"The abstract parent owns shared validation/state while a concrete child supplies request-specific behavior.","hint_1":"Use `ABC` plus `@abstractmethod` on `category()` and `details()`.","hint_2":"Use `super().__init__(household, priority, fulfilled)` in FoodRequest."},"starterCode":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\n# Create the FoodRequest and print its summary.\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\n# Create the FoodRequest and print its summary.\n"},"models_pantry_request_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass PantryRequest:\n VALID_PRIORITIES = {\"low\", \"medium\", \"high\"}\n\n def __init__(self, household, priority=\"medium\", fulfilled=False):\n # TODO: route household and priority through validated properties.\n # TODO: store fulfillment state privately.\n pass\n\n # TODO: add validated household and priority properties.\n\n @property\n def fulfilled(self):\n # TODO: expose the private fulfillment state.\n pass\n\n def mark_fulfilled(self):\n # TODO: update state and return the new fulfilled value.\n pass\n\n def is_open(self):\n # TODO: return whether the request is still open.\n pass\n\n # TODO: make category() and details() abstract methods.\n\n def summary(self):\n # TODO: combine the shared state with category() and details().\n pass\n"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n # TODO: reuse PantryRequest setup and validate food_type.\n pass\n\n # TODO: implement category() and details().\n"},"models_hygiene_request_py":{"content":"# HygieneRequest is added in the next milestone.\n"},"models___init___py":{"content":"# TODO: export PantryRequest and FoodRequest.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n"},"models_pantry_request_py":{"content":"$8d"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"# HygieneRequest is added in the next milestone.\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\"]\n"}},"solutionCode":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n","checks":{"0":{"message":"Create the `PantryRequest` class in `models/pantry_request.py`."},"1":{"message":"`FoodRequest.summary()` must return the Rivera family line shown in the expected example."},"2":{"message":"`main.py` must print the completed food-request summary."},"3":{"message":"Import both `ABC` and `abstractmethod` from `abc` in `models/pantry_request.py`."},"4":{"message":"Declare the base class as `class PantryRequest(ABC):`."},"5":{"message":"Mark the subclass contract with `@abstractmethod` in `models/pantry_request.py`."},"6":{"message":"Use properties to protect the request state and validation rules."},"7":{"message":"Declare `FoodRequest` as a subclass of `PantryRequest` in `models/food_request.py`."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"FOOD: Rivera family | priority=high | food=produce | fulfilled=False","sourceChecks":{"0":{"message":"Make `PantryRequest` inherit from `ABC`."},"1":{"message":"Use a `household` property and setter for validated state."},"2":{"message":"Use a `priority` property and setter for validated state."},"3":{"message":"Make both `category(self)` and `details(self)` abstract methods."},"4":{"message":"Keep FoodRequest inheriting from PantryRequest and reuse the parent constructor with `super()`."}}},"project_pantry_request_step_2_models":{"title":"Milestone 2: Add HygieneRequest and prove polymorphism","prompt":"Continue from the exact Milestone 1 workspace. Implement `HygieneRequest(PantryRequest)` in `models/hygiene_request.py`. Reuse the parent constructor with `super()`, convert `units` to an integer, reject values below 1, return `HYGIENE` from `category()`, and return `units=<value>` from `details()`. Then update `main.py` to build one FoodRequest and one HygieneRequest from the provided inputs, place them in one `requests` list, and use one `for` loop that calls the current object's shared `summary()` method. Do not branch with `isinstance()`, `type()`, `__class__`, or separate food/hygiene print logic. Keep the completed PantryRequest and FoodRequest unchanged.","hint":"The new subclass specializes the same abstract methods; the caller should trust the shared `summary()` interface.","help":{"concept":"This milestone retrieves inheritance, overriding, and branch-free polymorphism in one mixed collection.","hint_1":"Use `super().__init__` in HygieneRequest.","hint_2":"Inside the loop, call only `request.summary()`."},"starterCode":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\n\nhousehold = input()\npriority = input()\nfood_type = input()\n\nrequest = FoodRequest(household, priority, food_type)\nprint(request.summary())\n"},"models_pantry_request_py":{"content":"$8e"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"# Added in Milestone 2.\n"},"models___init___py":{"content":"# TODO: export PantryRequest, FoodRequest, and HygieneRequest.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n"},"models_pantry_request_py":{"content":"$8f"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"}},"solutionCode":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n","checks":{"0":{"message":"Preserve the correct `FoodRequest.summary()` behavior from the previous milestone."},"1":{"message":"`HygieneRequest.summary()` must return the Chen family line shown in the expected example."},"2":{"message":"`main.py` must print both request summaries."},"3":{"message":"Declare `HygieneRequest` as a subclass of `PantryRequest`."},"4":{"message":"Use a `for` loop in `main.py` to process the mixed request list."},"5":{"message":"Call `request.summary()` inside the loop instead of branching by request type."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"FOOD: Rivera family | priority=high | food=produce | fulfilled=False\nHYGIENE: Chen family | priority=medium | units=3 | fulfilled=False","sourceChecks":{"0":{"message":"Keep HygieneRequest inheriting from PantryRequest and reuse the shared constructor with `super()`."},"1":{"message":"Implement the required `category()` and `details()` methods."},"2":{"message":"Use one branch-free loop over `requests` and call the shared `summary()` method."}}},"project_pantry_request_step_3_service":{"title":"Milestone 3: Give PantryService ownership of the queue","prompt":"Continue from the exact Milestone 2 workspace. Implement `PantryService` in `services/pantry_service.py`. Store the mutable collection privately in `self._requests`; accept an optional starting collection and add each item through `add_request()`; expose a read-only `requests` property that returns a tuple; reject non-PantryRequest values in `add_request()`; implement `mark_fulfilled(household)` by calling the matching request's `mark_fulfilled()` method; count open requests through `request.is_open()`; and build summary lines through `request.summary()`. Update `main.py` to create the two request objects, create the service, fulfill the household supplied by input, print the service's summary lines, and print the open count. `main.py` must not reach into `_requests` or duplicate model state logic.","hint":"The service owns collection coordination; each request object still owns its own state and summary behavior.","help":{"concept":"Encapsulation protects the mutable collection while service methods delegate behavior to the model objects.","hint_1":"Return `tuple(self._requests)` from the property.","hint_2":"Call `request.mark_fulfilled()`, `request.is_open()`, and `request.summary()` rather than changing model fields."},"starterCode":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\n\nrequests = [\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n]\n\nfor request in requests:\n print(request.summary())\n"},"models_pantry_request_py":{"content":"$90"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"# Added in Milestone 3.\n"},"services___init___py":{"content":"# Package marker for imports.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$91"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"}},"solutionCode":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n","checks":{"0":{"message":"Create the `PantryService` class in `services/pantry_service.py`."},"1":{"message":"A new empty `PantryService` must report `0` open requests."},"2":{"message":"`main.py` must print the two summaries and the open-request count."},"3":{"message":"Store the mutable collection in `self._requests` inside `PantryService`."},"4":{"message":"Expose the collection through a read-only property instead of returning the internal list directly."},"5":{"message":"Delegate fulfillment to `request.mark_fulfilled()` instead of changing model state from the service."},"6":{"message":"Build service summary lines by calling `request.summary()` polymorphically."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"FOOD: Rivera family | priority=high | food=produce | fulfilled=True\nHYGIENE: Chen family | priority=medium | units=3 | fulfilled=False\nOPEN: 1","sourceChecks":{"0":{"message":"Keep the mutable list private and expose a tuple through a read-only property."},"1":{"message":"`add_request()` should accept only PantryRequest objects and append the validated object."},"2":{"message":"Delegate state, open-count, and summary behavior to request objects instead of duplicating it in the service."},"3":{"message":"Keep main.py outside the service's private `_requests` state."}}},"project_pantry_request_step_4_storage":{"title":"Milestone 4: Load request objects from CSV","prompt":"Continue from the exact Milestone 3 workspace. Implement `storage/request_storage.py`. `parse_fulfilled(value)` must treat `true`, `1`, and `yes` as fulfilled regardless of surrounding spaces or letter case. `load_requests(path)` must use `csv.DictReader`, construct FoodRequest or HygieneRequest from the `type` column, convert hygiene units to an integer, preserve priority and fulfilled state through the real constructors, and raise `ValueError` for an unknown type. The supplied `tests/check_storage.py` is the executable boundary test for this milestone; do not rewrite the models or service to compensate for storage bugs.","hint":"Storage may choose which concrete class to construct; once the object exists, the rest of the application uses the shared OOP interface.","help":{"concept":"A storage adapter translates serialized rows into validated domain objects without duplicating model/report rules.","hint_1":"Use `csv.DictReader` and normalize the `type`/fulfilled text.","hint_2":"Raise ValueError when the type is neither food nor hygiene."},"starterCode":"# Added in Milestone 4.\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$92"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"# Added in Milestone 4.\n"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"tests_check_storage_py":{"content":"# Added in Milestone 4.\n"}},"solutionFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$93"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$94"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"tests_check_storage_py":{"content":"$95"}},"solutionCode":"$96","checks":{"0":{"message":"`parse_fulfilled(\"yes\")` must return `True`."},"1":{"message":"`main.py` must print the three requests loaded from the CSV file."},"2":{"message":"Import `FoodRequest` into `storage/request_storage.py` so food rows become food objects."},"3":{"message":"Import `HygieneRequest` into `storage/request_storage.py` so hygiene rows become hygiene objects."},"4":{"message":"Read the CSV with `csv.DictReader`."},"5":{"message":"Print loaded objects through `request.summary()` in `main.py`."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"storage tests passed","sourceChecks":{"0":{"message":"Use Python's `csv` module for the storage adapter."},"1":{"message":"Normalize surrounding spaces/case and recognize true, 1, and yes."},"2":{"message":"Read request rows with `csv.DictReader`."},"3":{"message":"Construct the two concrete request types and reject an unknown type."}}},"project_pantry_request_step_5_reports_tests":{"title":"Milestone 5: Add the report and regression tests","prompt":"Continue from the exact Milestone 4 workspace. Implement `build_summary(requests)` in `reports/summary.py`: start with `NEIGHBORHOOD PANTRY REQUESTS`, append one `request.summary()` line per object, calculate open requests through `request.is_open()`, derive the fulfilled count, and return one newline-separated string. Do not branch on FoodRequest versus HygieneRequest in the report. Then complete `tests/check_requests.py`. Without using `inspect`, prove that PantryRequest cannot be instantiated while abstract; prove blank household and zero-unit validation; test a mixed PantryService; test fulfillment delegation and open count; and assert the full report for that mixed fixture. Keep the provided `run_checks()` function and final script print. Finally, update `main.py` to load the saved CSV requests and print `build_summary(requests)`.","hint":"Prove abstraction by attempting to instantiate the abstract base and catching TypeError; the report itself should use only the shared request interface.","help":{"concept":"Regression tests protect the architecture, while the report remains polymorphic and independent of concrete request types.","hint_1":"Use request.summary() and request.is_open() in the report.","hint_2":"Your tests should exercise validation, mixed objects, service state changes, and the returned report string."},"starterCode":"# Added in Milestone 5.\n","starterFiles":{"main_py":{"content":"from models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\nfrom services.pantry_service import PantryService\n\nfood_household = input()\nfood_priority = input()\nfood_type = input()\nhygiene_household = input()\nhygiene_priority = input()\nunits = int(input())\nhousehold_to_fulfill = input()\n\nservice = PantryService([\n FoodRequest(food_household, food_priority, food_type),\n HygieneRequest(hygiene_household, hygiene_priority, units),\n])\n\nservice.mark_fulfilled(household_to_fulfill)\n\nfor line in service.summary_lines():\n print(line)\n\nprint(\"OPEN:\", service.count_open_requests())\n"},"models_pantry_request_py":{"content":"$97"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$98"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"# Added in Milestone 5.\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"# Added in Milestone 5.\n"},"tests___init___py":{"content":"# Package marker for imports.\n"},"tests_check_storage_py":{"content":"$99"}},"solutionFiles":{"main_py":{"content":"from reports.summary import build_summary\nfrom storage.request_storage import load_requests\n\nrequests = load_requests(\"data/requests.csv\")\nprint(build_summary(requests))\n"},"models_pantry_request_py":{"content":"$9a"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$9b"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"def build_summary(requests):\n request_list = list(requests)\n lines = [\"NEIGHBORHOOD PANTRY REQUESTS\"]\n\n for request in request_list:\n lines.append(request.summary())\n\n open_count = sum(\n request.is_open()\n for request in request_list\n )\n fulfilled_count = len(request_list) - open_count\n\n lines.append(\n f\"OPEN: {open_count} | FULFILLED: {fulfilled_count}\"\n )\n return \"\\n\".join(lines)\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"$9c"},"tests___init___py":{"content":"# Package marker for imports.\n"},"tests_check_storage_py":{"content":"$9d"}},"solutionCode":"$9e","checks":{"0":{"message":"`main.py` must print the complete report with its heading, request lines, and totals."},"1":{"message":"Build every report row with `request.summary()` so the report remains polymorphic."},"2":{"message":"Calculate open totals with `request.is_open()` instead of reading or duplicating internal state rules."},"3":{"message":"Assert that `PantryRequest` is abstract with `isabstract(PantryRequest)`."},"4":{"message":"Add meaningful assertions in `tests/check_requests.py` for validation and mixed-subclass service behavior."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"request tests passed","sourceChecks":{"0":{"message":"Build the report from `request.summary()` and `request.is_open()` without concrete-type branches."},"1":{"message":"Prove the abstract base cannot be instantiated by catching TypeError."},"2":{"message":"Test both blank-household and zero-unit validation failures."},"3":{"message":"Add meaningful assertions for mixed summaries, fulfillment, open count, and the final report."},"4":{"message":"Keep main.py thin: load request objects and print the report."}}},"project_pantry_request_step_6_final_handoff":{"title":"Milestone 6: Deliver the final pantry coordinator","prompt":"Continue from the Milestone 5 workspace and deliver the application the pantry team will actually run. In `main.py`, create `PantryService(load_requests(\"data/requests.csv\"))`; fulfill the Rivera and Chen requests through `service.mark_fulfilled()`; add a fulfilled `HygieneRequest(\"Davis family\", \"medium\", 2, True)`; print the deterministic `build_summary(service.requests)` report; and then print exactly `PANTRY REQUEST COORDINATOR READY`. Keep the regression files in `tests/`, but do not import test modules into production `main.py`. In `README.md`, explain the responsibilities of models, services, storage, reports, tests, and main.py; mention validated properties, ABC/abstract methods, inheritance/super, overriding, and polymorphism; and include the run command `python main.py`.","hint":"The final runner should wire together production layers only. Regression files protect the project separately.","help":{"concept":"A production entry point orchestrates application code; test modules stay independent so they can verify the application without becoming a runtime dependency.","hint_1":"Load the CSV into PantryService, make the required state changes, then pass `service.requests` to `build_summary()`.","hint_2":"Document each folder's responsibility and the exact `python main.py` run command in README.md."},"starterCode":"from reports.summary import build_summary\nfrom storage.request_storage import load_requests\n\nrequests = load_requests(\"data/requests.csv\")\nprint(build_summary(requests))\n","starterFiles":{"main_py":{"content":"from reports.summary import build_summary\nfrom storage.request_storage import load_requests\n\nrequests = load_requests(\"data/requests.csv\")\nprint(build_summary(requests))\n"},"models_pantry_request_py":{"content":"$9f"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$a0"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"def build_summary(requests):\n request_list = list(requests)\n lines = [\"NEIGHBORHOOD PANTRY REQUESTS\"]\n\n for request in request_list:\n lines.append(request.summary())\n\n open_count = sum(\n request.is_open()\n for request in request_list\n )\n fulfilled_count = len(request_list) - open_count\n\n lines.append(\n f\"OPEN: {open_count} | FULFILLED: {fulfilled_count}\"\n )\n return \"\\n\".join(lines)\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"$a1"},"tests___init___py":{"content":"# Package marker for imports.\n"},"README_md":{"content":"# Neighborhood Pantry Request Coordinator\n\nComplete the final architecture and handoff notes in Milestone 6.\n"},"tests_check_storage_py":{"content":"$a2"}},"solutionFiles":{"main_py":{"content":"from models.hygiene_request import HygieneRequest\nfrom reports.summary import build_summary\nfrom services.pantry_service import PantryService\nfrom storage.request_storage import load_requests\n\nservice = PantryService(load_requests(\"data/requests.csv\"))\nservice.mark_fulfilled(\"Rivera family\")\nservice.mark_fulfilled(\"Chen family\")\nservice.add_request(\n HygieneRequest(\n \"Davis family\",\n \"medium\",\n 2,\n True,\n )\n)\n\nprint(build_summary(service.requests))\nprint(\"PANTRY REQUEST COORDINATOR READY\")\n"},"models_pantry_request_py":{"content":"$a3"},"models_food_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass FoodRequest(PantryRequest):\n def __init__(self, household, priority, food_type, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n cleaned = str(food_type).strip()\n if not cleaned:\n raise ValueError(\"food_type is required\")\n self.food_type = cleaned\n\n def category(self):\n return \"FOOD\"\n\n def details(self):\n return f\"food={self.food_type}\"\n"},"models_hygiene_request_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass HygieneRequest(PantryRequest):\n def __init__(self, household, priority, units, fulfilled=False):\n super().__init__(household, priority, fulfilled)\n\n units = int(units)\n if units < 1:\n raise ValueError(\"units must be at least 1\")\n self.units = units\n\n def category(self):\n return \"HYGIENE\"\n\n def details(self):\n return f\"units={self.units}\"\n"},"models___init___py":{"content":"from models.pantry_request import PantryRequest\nfrom models.food_request import FoodRequest\nfrom models.hygiene_request import HygieneRequest\n\n__all__ = [\"PantryRequest\", \"FoodRequest\", \"HygieneRequest\"]\n"},"services_pantry_service_py":{"content":"from models.pantry_request import PantryRequest\n\n\nclass PantryService:\n def __init__(self, requests=None):\n self._requests = []\n\n if requests is not None:\n for request in requests:\n self.add_request(request)\n\n @property\n def requests(self):\n return tuple(self._requests)\n\n def add_request(self, request):\n if not isinstance(request, PantryRequest):\n raise TypeError(\"request must be a PantryRequest\")\n self._requests.append(request)\n\n def mark_fulfilled(self, household):\n for request in self._requests:\n if request.household == household:\n request.mark_fulfilled()\n return True\n return False\n\n def count_open_requests(self):\n return sum(request.is_open() for request in self._requests)\n\n def summary_lines(self):\n return [request.summary() for request in self._requests]\n"},"services___init___py":{"content":"# Package marker for imports.\n"},"storage_request_storage_py":{"content":"$a4"},"storage___init___py":{"content":"# Package marker for imports.\n"},"data_requests_csv":{"content":"type,household,priority,detail,fulfilled\nfood,Rivera family,high,produce,false\nhygiene,Chen family,medium,3,false\nhygiene,Morgan family,low,5,true\n"},"reports_summary_py":{"content":"def build_summary(requests):\n request_list = list(requests)\n lines = [\"NEIGHBORHOOD PANTRY REQUESTS\"]\n\n for request in request_list:\n lines.append(request.summary())\n\n open_count = sum(\n request.is_open()\n for request in request_list\n )\n fulfilled_count = len(request_list) - open_count\n\n lines.append(\n f\"OPEN: {open_count} | FULFILLED: {fulfilled_count}\"\n )\n return \"\\n\".join(lines)\n"},"reports___init___py":{"content":"# Package marker for imports.\n"},"tests_check_requests_py":{"content":"$a5"},"tests___init___py":{"content":"# Package marker for imports.\n"},"README_md":{"content":"$a6"},"tests_check_storage_py":{"content":"$a7"}},"solutionCode":"from models.hygiene_request import HygieneRequest\nfrom reports.summary import build_summary\nfrom services.pantry_service import PantryService\nfrom storage.request_storage import load_requests\n\nservice = PantryService(load_requests(\"data/requests.csv\"))\nservice.mark_fulfilled(\"Rivera family\")\nservice.mark_fulfilled(\"Chen family\")\nservice.add_request(\n HygieneRequest(\n \"Davis family\",\n \"medium\",\n 2,\n True,\n )\n)\n\nprint(build_summary(service.requests))\nprint(\"PANTRY REQUEST COORDINATOR READY\")\n","checks":{"0":{"message":"`main.py` must print the complete final report and the readiness confirmation."},"1":{"message":"Explain **Abstraction** in `README.md`, including the role of `PantryRequest` as the abstract contract."},"2":{"message":"Explain **Polymorphism** in `README.md`, including how mixed request types share one interface."},"3":{"message":"Include the exact run command `python main.py` in `README.md`."},"4":{"message":"Call `run_checks()` from `main.py` before the final workflow."}},"workspaceFiles":{},"bundleMoved":{},"expectedOutput":"NEIGHBORHOOD PANTRY REQUESTS\nFOOD: Rivera family | priority=high | food=produce | fulfilled=True\nHYGIENE: Chen family | priority=medium | units=3 | fulfilled=True\nHYGIENE: Morgan family | priority=low | units=5 | fulfilled=True\nHYGIENE: Davis family | priority=medium | units=2 | fulfilled=True\nOPEN: 0 | FULFILLED: 4\nPANTRY REQUEST COORDINATOR READY","sourceChecks":{"0":{"message":"Keep production `main.py` independent of test modules, then load the CSV through PantryService, apply the required state changes, print the final report, and print the readiness line."},"1":{"message":"Document the responsibility of every production/test layer."},"2":{"message":"Document the retrieved OOP concepts and the exact run command."}}}}}}},"python-8-object-oriented-foundations":{"class-files-and-instances":{"label":"Class Files and Instances","summary":"Define a minimal class in a model file, import it from `main.py`, and create an instance across that file boundary.","cards":{"sketch0":{"title":"Define the class file"},"sketch1":{"title":"Import and use the class"},"sketch2":{"title":"Keep files clean"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_class_files_and_instances_sketch0":{"title":"Define a minimal Car class","prompt":"In `models/car.py`, define a class named `Car` and put `pass` in its body so the class is valid but intentionally empty. Leave `main.py` unchanged. Do not add a constructor yet.","hint":"The class definition belongs in `models/car.py`. Use `pass` as the placeholder body.","help":{"concept":"`pass` is a placeholder statement. It lets you define a valid class before adding real behavior.","hint_1":"Start the definition with `class Car:`.","hint_2":"Indent `pass` inside the class body."},"starterCode":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet.","starterFiles":{"main_py":{"content":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet."},"models_car_py":{"content":"# Define the Car class shell below.\n"}},"solutionCode":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet.","solutionFiles":{"main_py":{"content":"# The class definition belongs in models/car.py.\n# You do not need to add code in main.py yet."},"models_car_py":{"content":"class Car:\n pass"}},"checks":{"0":{"message":"Define a Car class in models/car.py."},"1":{"message":"The class shell should be constructible with no arguments yet."}},"sourceChecks":{"0":{"message":"Define `Car` in `models/car.py` with `pass` in its body."}}},"try_class_files_and_instances_sketch1":{"title":"Import and use Car from the model file","prompt":"`models/car.py` already defines the empty `Car` class. In `main.py`, import `Car` from the `models.car` module and create one `Car` object. Keep the class definition in `models/car.py`; do not copy the class into `main.py`. No output is required.","hint":"Import the class from the model module, then call the imported class to create one object.","help":{"concept":"A model file owns the class definition. Another file imports that class and can then create objects from it.","hint_1":"The module path is `models.car`.","hint_2":"After importing `Car`, call `Car()` once in `main.py`."},"starterCode":"# Import the Car class.\n# Then create one Car object.","starterFiles":{"main_py":{"content":"# Import the Car class.\n# Then create one Car object."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Import Car and create one object.\nclass Car:\n pass"}},"solutionCode":"from models.car import Car\n\ncar = Car()","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car()"},"models_car_py":{"content":"class Car:\n pass"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should still be constructible with no arguments."},"2":{"message":"Create one Car object in main.py."}},"sourceChecks":{"0":{"message":"Import the `Car` class/module from `models.car` in `main.py`."}}},"try_class_files_and_instances_sketch2":{"title":"Keep the model and main script separate","prompt":"Keep the `Car` class in `models/car.py`. Keep `main.py` as the small script that imports the class and creates one object. Add `print(\"Car object ready\")` in `main.py` so the program shows that it ran.","hint":"Do not move the class into `main.py`. Import it from the model file.","help":{"concept":"A clean multifile project keeps model code in a model file and keeps the main script focused on using that model.","hint_1":"`models/car.py` should contain the class.","hint_2":"`main.py` should import `Car`, create `car = Car()`, and print the ready message."},"starterCode":"from models.car import Car\n\ncar = Car()\n\n# Print a short ready message below.","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car()\n\n# Print a short ready message below."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Keep the model and main script separate.\nclass Car:\n pass"}},"solutionCode":"from models.car import Car\n\ncar = Car()\nprint(\"Car object ready\")","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car()\nprint(\"Car object ready\")"},"models_car_py":{"content":"class Car:\n pass"}},"checks":{"0":{"message":"Keep the Car class defined in the model file."},"1":{"message":"Car should still be constructible with no arguments."},"2":{"message":"Create one Car object in main.py."},"3":{"message":"Print one short ready message from main.py."}},"expectedOutput":"Car object ready"}},"practice":{"mc-class-files-and-instances-class-role":{"title":"Separate the two files","prompt":"Which statements keep the class definition and the script that uses it cleanly separated? Choose all that apply.","hint":"The model file owns the class definition; `main.py` imports and uses it.","help":{"concept":"A clean file boundary keeps reusable model code in the model file and keeps `main.py` focused on using that model.","hint_1":"Look for one statement about `models/car.py` and one about `main.py`.","hint_2":"Do not duplicate the class definition in `main.py`."},"options":{"a":"`models/car.py` defines the `Car` class.","b":"`main.py` imports `Car` and creates objects from it.","c":"`main.py` should copy the full `Car` class definition before using it.","d":"`models/car.py` should run the whole program and print the final output."}},"sc-class-files-and-instances-pass-meaning":{"title":"Why use pass?","prompt":"Why can an empty class use `pass`?","hint":"`pass` lets Python keep a block valid even when there is no real code yet.","help":{"concept":"`pass` is a placeholder. It keeps an empty class body syntactically valid until you add real code later.","hint_1":"A class body cannot be completely empty.","hint_2":"Choose the answer about a placeholder."},"options":{"a":"`pass` creates every method automatically.","b":"`pass` is a placeholder that keeps the empty class valid.","c":"`pass` imports the class into main.py.","d":"`pass` prints the object."}},"fb-class-files-and-instances-import-name":{"title":"Complete the module path","prompt":"Complete the import so `main.py` imports `Car` from the file `models/car.py`.","hint":"Python module paths use dots instead of `/` and omit the `.py` extension.","help":{"concept":"The file path `models/car.py` is imported with the module path `models.car`.","hint_1":"Replace the slash with a dot.","hint_2":"Use `models.car`."},"template":"from [blank1] import Car","choices":["models.car","models/car.py","car","main"]},"dr-class-files-and-instances-order":{"title":"Order the first class workflow","prompt":"Put the steps in the order you follow when creating a class in a model file.","hint":"Start with the class file before importing it.","help":{"concept":"A clean first workflow is: define the class, import it, create one object, then run main.py.","hint_1":"You cannot import a class that has not been defined yet.","hint_2":"Creating the object comes after the import."},"tokens":{"t1":"Define the class in models/car.py","t2":"Import Car in main.py","t3":"Create one object with Car()","t4":"Run main.py"}},"project-step-account-class":{"title":"Create the Account class","prompt":"Practice creating a small account model. Define an `Account` class in `models/account.py` with an `__init__(self, owner, balance)` constructor that stores `owner` and `balance`. In the main code, create `Account(\"Ava\", 120)` and print the owner on one line and the balance on the next line.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"# main.py\nfrom models.account import Account\n\n# Create Ava's account and print owner then balance.","starterFiles":{"main_py":{"content":"from models.account import Account\n\n# Create Ava's account and print owner then balance."},"models_account_py":{"content":""}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\nprint(account.owner)\nprint(account.balance)"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\nprint(account.owner)\nprint(account.balance)","checks":{"0":{"message":"Define a class named Account."},"1":{"message":"Account should accept owner and balance."},"2":{"message":"Store owner and balance on the Account instance."},"3":{"message":"Create one Account object in the main code."},"4":{"message":"Print the owner and balance on separate lines."}}},"project-step-account-methods":{"title":"Add account methods","prompt":"Practice putting account behavior on the model. Keep the provided `Account` class with `owner` and `balance`, then add a `deposit(self, amount)` method that increases the balance and a `summary(self)` method that returns `<owner>: $<balance>`. The main code creates `Account(\"Ava\", 120)`, deposits `30`, and prints the summary.","hint":"One method changes state, and the other reports the current state.","help":{"concept":"This step checks that methods can both update object state and return text based on the updated attributes.","hint_1":"`deposit` should add the incoming amount to `self.balance`.","hint_2":"After calling `deposit(30)`, the summary should reflect the new balance, not the original one."},"starterCode":"# main.py\nfrom models.account import Account\n\naccount = Account(\"Ava\", 120)\n\n# Deposit 30, then print the summary.","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\n\n# Deposit 30, then print the summary."},"models_account_py":{"content":""}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\naccount.deposit(30)\nprint(account.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def summary(self):\n return f\"{self.owner}: ${self.balance}\"\n\n def deposit(self, amount):\n self.balance += amount\n return self.balance"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 120)\naccount.deposit(30)\nprint(account.summary())","checks":{"0":{"message":"Keep the Account class defined."},"1":{"message":"Account should still store owner and balance."},"2":{"message":"summary() should report the current owner and balance."},"3":{"message":"summary() should exist before any deposit."},"4":{"message":"deposit(30) should update the balance to 150."},"5":{"message":"Create one Account object in the main code."},"6":{"message":"Print the summary after depositing."}}},"project-step-two-accounts":{"title":"Keep state separate across two accounts","prompt":"Practice working with two instances of the same class. Keep the provided `Account` class with `owner`, `balance`, `deposit`, and `summary`. The main code creates Ava and Noah accounts and deposits into Ava's account only. Finish the code so the two printed summaries show that each object keeps its own state.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"# main.py\nfrom models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\n# Deposit 30 into Ava's account only.\n# Print Ava's summary, then Noah's summary.","starterFiles":{"main_py":{"content":"from models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\n# Deposit 30 into Ava's account only.\n# Print Ava's summary, then Noah's summary."},"models_account_py":{"content":""}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\nava_account.deposit(30)\nprint(ava_account.summary())\nprint(noah_account.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n self.balance += amount\n\n def summary(self):\n return f\"{self.owner}: ${self.balance}\""}},"solutionCode":"from models.account import Account\n\nava_account = Account(\"Ava\", 120)\nnoah_account = Account(\"Noah\", 90)\n\nava_account.deposit(30)\nprint(ava_account.summary())\nprint(noah_account.summary())","checks":{"0":{"message":"Keep the Account class defined."},"1":{"message":"Each Account should store owner and balance."},"2":{"message":"Ava's account should update to 150 after deposit(30)."},"3":{"message":"Noah's summary should still show the original balance."},"4":{"message":"Create two Account objects in the main code."},"5":{"message":"Print both account summaries on separate lines."}}}}},"constructors-and-object-state":{"label":"Constructors and Object State","summary":"Use `__init__` to create per-object state, distinguish instance state from class-level state, and keep mutable lists separate between objects.","cards":{"sketch0":{"title":"Initialize object state"},"sketch1":{"title":"Class state vs instance state"},"sketch2":{"title":"Keep mutable state per object"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_constructors_and_object_state_sketch0":{"title":"Initialize a Car's state","prompt":"`main.py` already creates a `Car` and reads its attributes. In `models/car.py`, replace the empty class body with `__init__(self, make, model, miles)`. Store the incoming values on `self.make`, `self.model`, and `self.miles`. Leave `main.py` unchanged.","hint":"The constructor receives the three starting values and assigns each one to an attribute on `self`.","help":{"concept":"`__init__` establishes instance state when an object is created.","hint_1":"Define `__init__` inside `class Car`.","hint_2":"Assign make, model, and miles to matching attributes on `self`."},"starterCode":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n # Add __init__ so each Car stores make, model, and miles.\n pass\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Nissan\", \"Leaf\", 6000)\n\nprint(car.make)\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should be constructible with make, model, and miles."},"2":{"message":"Store make, model, and miles as attributes on the object."},"3":{"message":"Print the requested attributes on separate lines."}},"expectedOutput":"Nissan\n6000","sourceChecks":{"0":{"message":"Define `__init__(self, make, model, miles)` inside `Car`."},"1":{"message":"Store `make` on `self.make`."},"2":{"message":"Store `model` on `self.model`."},"3":{"message":"Store `miles` on `self.miles`."}}},"try_constructors_and_object_state_sketch1":{"title":"Add one class-level value","prompt":"In `models/car.py`, add the class variable `wheels = 4` directly inside `class Car`, outside `__init__`. Keep `make`, `model`, and `miles` as instance variables on `self`. In `main.py`, print `Car.wheels`, then `outback.make`, then `mini.make`, each on its own line.","hint":"The shared value belongs in the class body; values that differ between cars stay on `self`.","help":{"concept":"A class variable is class-level state; instance variables live on one object through `self`.","hint_1":"Put `wheels = 4` above `__init__`, not inside it.","hint_2":"Read the shared value with `Car.wheels`."},"starterCode":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\n# Print the class-level wheel count, then each car's make.\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\n# Print the class-level wheel count, then each car's make.\n"},"models_car_py":{"content":"class Car:\n # Add the class variable wheels = 4 here.\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n"}},"solutionCode":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\nprint(Car.wheels)\nprint(outback.make)\nprint(mini.make)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\noutback = Car(\"Subaru\", \"Outback\", 40000)\nmini = Car(\"Mini\", \"Cooper\", 15000)\n\nprint(Car.wheels)\nprint(outback.make)\nprint(mini.make)\n"},"models_car_py":{"content":"class Car:\n wheels = 4\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should still accept make, model, and miles."},"2":{"message":"Keep make, model, and miles as per-object attributes."},"3":{"message":"Create two Car objects in main.py."},"4":{"message":"Print the shared wheel count and the two requested makes."}},"expectedOutput":"4\nSubaru\nMini","sourceChecks":{"0":{"message":"Define `wheels = 4` as a class variable directly inside `Car`."},"1":{"message":"Print the shared value from `Car.wheels`."},"2":{"message":"Print `outback.make`."},"3":{"message":"Print `mini.make`."}}},"try_constructors_and_object_state_sketch2":{"title":"Give each Car its own mutable list","prompt":"`main.py` already creates two cars, appends one service note to the first car, and prints both lists. In `models/car.py`, create `self.service_notes = []` inside `__init__` so every `Car` gets a separate list. Leave `main.py` unchanged.","hint":"Create the empty list on `self` inside the constructor, not once in the class body.","help":{"concept":"Mutable per-object state should be created separately for each instance.","hint_1":"Add the list assignment inside `__init__`.","hint_2":"The required attribute is `self.service_notes`."},"starterCode":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n"},"models_car_py":{"content":"class Car:\n wheels = 4\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n # Give each Car its own empty service_notes list.\n"}},"solutionCode":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\nfirst_car = Car(\"Hyundai\", \"Elantra\", 25000)\nsecond_car = Car(\"Chevrolet\", \"Bolt\", 9000)\n\nfirst_car.service_notes.append(\"oil change\")\n\nprint(first_car.service_notes)\nprint(second_car.service_notes)\n"},"models_car_py":{"content":"class Car:\n wheels = 4\n\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n self.service_notes = []\n"}},"checks":{"0":{"message":"Keep the Car class defined."},"1":{"message":"Car should still accept make, model, and miles."},"2":{"message":"Each Car should receive its own service_notes list."},"3":{"message":"Create two Car objects."},"4":{"message":"Only the first car should contain the new service note."}},"expectedOutput":"['oil change']\n[]","sourceChecks":{"0":{"message":"Create `self.service_notes = []` inside `__init__`."}}}},"practice":{"mc-constructors-and-object-state-storing-values":{"title":"Class state or instance state?","prompt":"Which statements correctly distinguish class variables from instance variables? Choose all that apply.","hint":"Values on `self` belong to one object; values such as `Car.wheels` live at the class level.","help":{"concept":"Instance variables are stored on one object through `self`. Class variables are defined in the class body.","hint_1":"Look for `self.` when identifying per-object state.","hint_2":"A class-level value can be read from the class itself."},"options":{"a":"`self.make` can differ from one `Car` object to another.","b":"`Car.wheels` is class-level state.","c":"Every value assigned on `self` is shared by all `Car` objects.","d":"A class variable is recreated separately inside every object."}},"sc-constructors-and-object-state-purpose":{"title":"Where should per-car notes live?","prompt":"Each `Car` needs a separate mutable list of service notes. Where should that list be created?","hint":"The list must be new for each object.","help":{"concept":"Create mutable per-object data inside `__init__` and assign it to `self`.","hint_1":"Avoid one list shared in the class body.","hint_2":"Choose the option that creates a fresh list per `Car`."},"options":{"a":"Inside `__init__` as `self.service_notes = []`","b":"Once in the class body as `service_notes = []`","c":"Only as a local list in `main.py`","d":"Inside a `print()` call"}},"fb-constructors-and-object-state-init-name":{"title":"Name the initializer","prompt":"Complete the method definition Python uses to initialize each new `Car` with starting state.","hint":"The special method name starts and ends with two underscores.","help":{"concept":"`__init__` runs when a new object is created and establishes its starting instance state.","hint_1":"The name means initialize.","hint_2":"Use `__init__`."},"template":"def [blank1](self, make, model, miles):","choices":["__init__","init","constructor","self"]},"dr-constructors-and-object-state-flow":{"title":"Order the state setup","prompt":"Put these steps in a clear order.","hint":"Define shared information first, then create per-object state.","help":{"concept":"The class body can hold shared values; the constructor creates each object's own state.","hint_1":"The class definition comes first.","hint_2":"Use the object after it has been created."},"tokens":{"t1":"Define the class variable in the class body","t2":"Define `__init__` with starting values","t3":"Store per-object values on `self`","t4":"Create an object and read its state"}},"ci-constructors-and-object-state-add-method":{"title":"Add a summary method that reads object state","prompt":"The tracker wants a readable summary for each transaction. In `models/transaction.py`, keep the constructor and add a `summary` method that returns text in this format: `Coffee: -4` or `Paycheck: 1200`. The method should build the string from the object's stored attributes.","hint":"Read the task \"Add a summary method that reads object state\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Add a summary method that reads object state\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n","solutionCode":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n","starterFiles":{"main_py":{"content":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n"},"models_transaction_py":{"content":"class Transaction:\n def __init__(self, label, amount):\n self.label = label\n self.amount = amount\n\n # Add summary() so it returns text built from the stored attributes.\n"}},"solutionFiles":{"main_py":{"content":"from models.transaction import Transaction\n\nfor transaction in [Transaction(\"Coffee\", -4), Transaction(\"Paycheck\", 1200)]:\n print(transaction.summary())\n"},"models_transaction_py":{"content":"class Transaction:\n def __init__(self, label, amount):\n self.label = label\n self.amount = amount\n\n def summary(self):\n return f\"{self.label}: {self.amount}\"\n"}},"checks":{"0":{"message":"Define a Transaction class."},"1":{"message":"Transaction should still accept label and amount."},"2":{"message":"summary should return text built from the stored label and amount."},"3":{"message":"summary should work for different transaction objects too."}}},"ci-constructors-and-object-state-deposit-method":{"title":"Track deposits on an account object","prompt":"Return to `models/account.py`. Define an `Account` class with a constructor that stores `owner` and `balance`, then add a `deposit` method that increases the balance. The provided workspace will create an account, make one or more deposits, and inspect the final stored balance.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n","solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n pass\n\n def deposit(self, amount):\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 100)\naccount.deposit(20)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n self.balance = self.balance + amount\n"}},"checks":{"0":{"message":"Define an Account class."},"1":{"message":"Account should accept owner and balance."},"2":{"message":"A deposit should increase the stored balance."},"3":{"message":"Multiple deposits should keep updating the same balance attribute."}}},"ci-constructors-and-object-state-ledger-step":{"title":"Build a ledger account that keeps owner, balance, and note","prompt":"The tracker now wants a slightly richer account model. In `models/account.py`, define an `Account` class whose constructor accepts `owner`, `balance`, and `note`. Store all three as attributes. Then add a `deposit` method that increases `balance` and a `describe` method that returns text in this format: `Rae | 90 | starter fund`. The workspace will create an object, update it, and call `describe()`.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n","solutionCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance, note):\n pass\n\n def deposit(self, amount):\n pass\n\n def describe(self):\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70, \"starter fund\")\naccount.deposit(20)\nprint(account.describe())\n"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance, note):\n self.owner = owner\n self.balance = balance\n self.note = note\n\n def deposit(self, amount):\n self.balance = self.balance + amount\n\n def describe(self):\n return f\"{self.owner} | {self.balance} | {self.note}\"\n"}},"checks":{"0":{"message":"Define an Account class."},"1":{"message":"Account should accept owner, balance, and note."},"2":{"message":"Store all three constructor values as instance attributes."},"3":{"message":"deposit should update the stored balance."},"4":{"message":"describe should return a string built from the stored state."}}}}},"encapsulation-and-validation":{"label":"Encapsulation and Validation","summary":"Protect object state by validating state-changing methods, then use a property setter when direct attribute assignment also needs one controlled validation path.","cards":{"sketch0":{"title":"Validate state-changing methods"},"sketch1":{"title":"Protect direct assignment with a property"},"sketch2":{"title":"Clean final behavior"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_encapsulation_and_validation_sketch0":{"title":"Protect mileage inside drive()","prompt":"`main.py` is already complete. In `models/car.py`, update the existing `drive(self, miles)` method so it changes `self.miles` only when the requested `miles` value is greater than `0`. For zero or a negative value, leave the stored mileage unchanged. Always return the car's current mileage. Leave `main.py` unchanged.","hint":"Check the requested distance before mutating `self.miles`, then return the current mileage.","help":{"concept":"Validation belongs next to the state change it protects. Invalid requests should not mutate the object.","hint_1":"Only positive distances are valid.","hint_2":"Return the current mileage after the validation decision."},"starterCode":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n # Validate the requested distance before changing self.miles.\n self.miles += miles\n return self.miles\n"}},"solutionCode":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nvalid_drive = int(input())\ninvalid_drive = int(input())\n\ncar = Car(\"Honda\", \"Civic\", start)\n\nprint(car.drive(valid_drive))\nprint(car.drive(invalid_drive))\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n if miles > 0:\n self.miles += miles\n return self.miles\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should still accept make, model, and starting mileage."},"2":{"message":"A positive drive should update and return the new mileage."},"3":{"message":"A negative drive must leave the mileage unchanged."},"4":{"message":"Zero and negative requests must preserve state for other valid starting values too."}},"expectedOutput":"110\n110","sourceChecks":{"0":{"message":"Keep the validation inside `drive(self, miles)` on `Car`."}}},"try_encapsulation_and_validation_sketch1":{"title":"Validate direct mileage assignment","prompt":"`main.py` is already complete. In `models/car.py`, keep `_miles` as the backing attribute and add a `miles` property. The `@property` getter `miles(self)` must return the backing mileage. Add a `@miles.setter` setter that changes the backing mileage only when the new value is `0` or greater. Negative assignments must leave the current mileage unchanged. Keep `__init__` routing the starting value through `self.miles = miles`. Leave `main.py` unchanged.","hint":"The getter exposes the backing value. The setter validates before replacing that value.","help":{"concept":"A property preserves normal attribute syntax while giving the object one controlled validation path.","hint_1":"Use `@property` for the getter and `@miles.setter` for the setter.","hint_2":"Only non-negative values should replace `_miles`."},"starterCode":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self._miles = 0\n self.miles = miles\n\n # Add the miles property getter and setter below.\n"}},"solutionCode":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\nstart = int(input())\nnew_miles = int(input())\ninvalid_miles = int(input())\n\ncar = Car(\"Toyota\", \"Prius\", start)\n\nprint(car.miles)\n\ncar.miles = new_miles\nprint(car.miles)\n\ncar.miles = invalid_miles\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self._miles = 0\n self.miles = miles\n\n @property\n def miles(self):\n return self._miles\n\n @miles.setter\n def miles(self, value):\n if value >= 0:\n self._miles = value\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should remain constructible with a valid starting mileage."},"2":{"message":"The public `miles` attribute should still be readable."},"3":{"message":"Print the final miles."}},"expectedOutput":"100\n150\n150","sourceChecks":{"0":{"message":"Define `miles` with the `@property` decorator."},"1":{"message":"Define a setter for the `miles` property."},"2":{"message":"Route the constructor's starting mileage through the `miles` property."}}},"try_encapsulation_and_validation_sketch2":{"title":"Use validated behavior with a summary","prompt":"Use the final validated `Car` class. In `main.py`, create `Car(\"Honda\", \"Civic\", 0)`, call `drive(20)`, call `drive(-3)`, call `drive(50)`, then print `summary()`. The invalid call should be ignored, so the summary should show `70` miles.","hint":"The negative drive should not change the object. The two positive drives should add up to 70 miles.","help":{"concept":"Encapsulation means the object protects its own state and reports a trustworthy result.","hint_1":"Call the methods in the order given.","hint_2":"Print `car.summary()` after all three calls."},"starterCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\n\n# Drive 20 miles, ignore -3, then drive 50 more.\n# Print the final summary.","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\n\n# Drive 20 miles, ignore -3, then drive 50 more.\n# Print the final summary."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Use validated behavior with a summary.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n if miles > 0:\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\ncar.drive(20)\ncar.drive(-3)\ncar.drive(50)\n\nprint(car.summary())","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Civic\", 0)\ncar.drive(20)\ncar.drive(-3)\ncar.drive(50)\n\nprint(car.summary())"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n if miles > 0:\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"The final summary should use validated miles."},"1":{"message":"Print one clean summary line."},"2":{"message":"Print one clean summary line."}},"expectedOutput":"Honda Civic - 70 miles"}},"practice":{"mc-encapsulation-and-validation-safe-design":{"title":"Choose controlled state changes","prompt":"Which designs keep validation close to the state it protects? Choose all that apply.","hint":"Look for one controlled path that every caller uses.","help":{"concept":"State-changing methods and property setters can both keep a validation rule inside the object.","hint_1":"A method can validate before mutation.","hint_2":"A property setter can validate direct assignment."},"options":{"a":"`drive()` checks a distance before changing the car's mileage.","b":"`main.py` directly repairs `_miles` whenever a value looks wrong.","c":"A `miles` property setter validates `car.miles = value` assignments.","d":"Every caller invents its own validation rule before touching the object."}},"sc-encapsulation-and-validation-why-inside-class":{"title":"Why use a property setter?","prompt":"Why is a property setter useful for a value such as `miles`?","hint":"Think about normal assignment syntax plus validation.","help":{"concept":"A property setter lets callers assign normally while the object controls whether the new value is accepted.","hint_1":"The caller can still write `car.miles = value`.","hint_2":"The setter owns the validation rule."},"options":{"a":"It prevents callers from reading the attribute at all.","b":"It keeps normal assignment syntax while validating the new value inside the object.","c":"It makes every instance share one mileage value.","d":"It removes the need for an initializer."}},"fb-encapsulation-and-validation-condition":{"title":"Trace a rejected assignment","prompt":"A car currently has `miles = 150`. Its property setter ignores negative values. After `car.miles = -20`, what is `car.miles`?","hint":"A rejected assignment leaves the stored state unchanged.","help":{"concept":"Validation protects the existing object state when an assignment is invalid.","hint_1":"The setter does not accept `-20`.","hint_2":"The previous value remains `150`."},"template":"car.miles == [blank1]","choices":["150","-20","0","170"]},"dr-encapsulation-and-validation-update-order":{"title":"Order the safe update","prompt":"Put the validation workflow in order.","hint":"Check the value before changing the attribute.","help":{"concept":"Safe methods receive a value, check it, update only if allowed, then return the current state.","hint_1":"Never update before checking.","hint_2":"Returning happens after the check/update decision."},"tokens":{"t1":"Receive the requested value","t2":"Check whether the value is valid","t3":"Update state only when valid","t4":"Return the current state"}},"ci-account-summary-method":{"title":"Create a summary method for account state","prompt":"A volunteer dashboard needs a readable account summary. In `models/account.py`, complete `summary` so it returns a string in this exact format: `Owner: <owner>, Balance: <balance>`. Do not print inside the method; return the string instead. `main.py` already prints the returned summary for two accounts.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())","starterFiles":{"main_py":{"content":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def summary(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def summary(self):\n return f\"Owner: {self.owner}, Balance: {self.balance}\""}},"solutionCode":"from models.account import Account\n\nfirst = Account(\"Mina\", 125)\nsecond = Account(\"Leo\", 40)\nprint(first.summary())\nprint(second.summary())","checks":{"0":{"message":"Define the Account class."},"1":{"message":"summary should return the formatted string for Mina's account."},"2":{"message":"summary should return the formatted string for Leo's account."}}},"ci-account-withdraw":{"title":"Add a validated withdraw method","prompt":"Your club account tracker now needs withdrawals. In `models/account.py`, complete `withdraw` so it subtracts the amount only when the amount is greater than 0 and no larger than the current balance. Return `True` for a successful withdrawal and `False` otherwise. `main.py` already checks one valid and one invalid withdrawal.","hint":"Read the task \"Add a validated withdraw method\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Add a validated withdraw method\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"# main.py\nfrom models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)\n\n# models/account.py\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n # subtract only when the amount is valid\n pass","starterFiles":{"main_py":{"content":"# main.py\nfrom models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)\n\n# models/account.py\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n # subtract only when the amount is valid\n pass"},"models_account_py":{"content":"class Account:\n def __init__(self, balance):\n self.balance = balance\n\n def withdraw(self, amount):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance -= amount\n return True\n return False"}},"solutionCode":"from models.account import Account\n\ntrip = Account(\"Trip Fund\", 90)\nprint(trip.withdraw(30))\nprint(trip.balance)\n\nsupplies = Account(\"Supplies\", 20)\nprint(supplies.withdraw(25))\nprint(supplies.balance)","checks":{"0":{"message":"Define the Account class."},"1":{"message":"Account should be constructible with owner and balance."},"2":{"message":"A valid withdrawal should return True."},"3":{"message":"A valid withdrawal should reduce the balance."},"4":{"message":"An oversized withdrawal should return False."},"5":{"message":"An invalid withdrawal should leave the balance unchanged."}}},"ci-helper-is_positive_amount":{"title":"Build a helper that checks positive amounts","prompt":"Your team wants a reusable validation helper. In `helpers/validation.py`, complete `is_positive_amount` so it returns `True` when the number is greater than 0 and `False` otherwise. `main.py` uses that helper inside `Account.deposit`, so the helper must work for both valid and invalid amounts.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"# main.py\nfrom helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)\n\n# helpers/validation.py\ndef is_positive_amount(amount):\n # return True only for amounts greater than 0\n pass\n\n# models/account.py\nfrom helpers.validation import is_positive_amount\n\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if is_positive_amount(amount):\n self.balance += amount\n return True\n return False","starterFiles":{"main_py":{"content":"# main.py\nfrom helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)\n\n# helpers/validation.py\ndef is_positive_amount(amount):\n # return True only for amounts greater than 0\n pass\n\n# models/account.py\nfrom helpers.validation import is_positive_amount\n\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if is_positive_amount(amount):\n self.balance += amount\n return True\n return False"},"models_account_py":{"content":"class Account:\n def __init__(self, balance):\n self.balance = balance\n\n def deposit(self, amount):\n pass"},"helpers_validation_py":{"content":"def is_positive_amount(amount):\n pass"}},"solutionFiles":{"main_py":{"content":"from helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)"},"models_account_py":{"content":"from helpers.validation import is_positive_amount\n\nclass Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if is_positive_amount(amount):\n self.balance += amount\n return True\n return False"},"helpers_validation_py":{"content":"def is_positive_amount(amount):\n return amount > 0"}},"solutionCode":"from helpers.validation import is_positive_amount\nfrom models.account import Account\n\nfirst = Account(\"Club\", 50)\nprint(first.deposit(10))\nprint(first.balance)\n\nsecond = Account(\"Snacks\", 50)\nprint(second.deposit(0))\nprint(second.balance)","checks":{"0":{"message":"10 should be treated as a positive amount."},"1":{"message":"0 should not be treated as a positive amount."},"2":{"message":"Negative numbers should return False."},"3":{"message":"The helper should support a valid deposit."},"4":{"message":"A non-positive amount should leave the balance unchanged."}}}}},"methods-and-responsibility":{"label":"Methods and Responsibility","summary":"Put behavior beside the object state it uses, return useful results from model methods, and keep application-wide coordination outside the model.","cards":{"sketch0":{"title":"Behavior that belongs to one object"},"sketch1":{"title":"Keep responsibilities separated"},"sketch2":{"title":"Static method"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_methods_and_responsibility_sketch0":{"title":"Add behavior that changes one Car","prompt":"`main.py` already creates a `Car`, calls `drive(40)`, and prints both the returned value and the car's final mileage. In `models/car.py`, define the instance method `drive(self, miles)`. It must increase `self.miles` by the given amount, update the object, and return the new mileage. Leave `main.py` unchanged.","hint":"This behavior belongs on `Car` because it changes one car's own mileage.","help":{"concept":"An instance method receives `self` and can change the state stored on that object.","hint_1":"Define `drive(self, miles)` inside `class Car`.","hint_2":"Update `self.miles`, then return its new value."},"starterCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n # Add drive(self, miles) here.\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Honda\", \"Fit\", 10000)\n\nprint(car.drive(40))\nprint(car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should still accept make, model, and miles."},"2":{"message":"Keep the existing per-object state."},"3":{"message":"`drive(40)` should return the updated mileage."},"4":{"message":"`drive(40)` must actually update `self.miles`, not only compute a return value."},"5":{"message":"`drive` should work for other valid starting mileages and distances."},"6":{"message":"Keep the provided two-line demonstration in `main.py`."}},"expectedOutput":"10040\n10040","sourceChecks":{"0":{"message":"Define `drive(self, miles)` as an instance method on `Car`."}}},"try_methods_and_responsibility_sketch1":{"title":"Return a summary of one Car","prompt":"`main.py` already creates one `Car` and prints `car.summary()`. In `models/car.py`, define the instance method `summary(self)`. Return a string in the format `MAKE MODEL - MILES miles` using that object's `make`, `model`, and `miles` attributes. The method must return the string; do not print inside `summary`. Leave `main.py` unchanged.","hint":"The summary belongs on `Car` because it reports one car's state. Return the string so `main.py` can decide to print it.","help":{"concept":"A model method can report one object's state while the caller remains responsible for display or application coordination.","hint_1":"Define `summary(self)` inside `Car`.","hint_2":"Build and return the string from `self.make`, `self.model`, and `self.miles`."},"starterCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n # Add summary(self) here.\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"Prius\", 62)\n\nprint(car.summary())\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\"\n"}},"checks":{"0":{"message":"Keep `Car` defined in `models/car.py`."},"1":{"message":"`Car` should remain constructible."},"2":{"message":"`summary()` should return the requested text for the visible car."},"3":{"message":"`summary()` should use the object's actual state, not hard-coded visible values."},"4":{"message":"Keep the provided `main.py` call that prints the returned summary."}},"expectedOutput":"Toyota Prius - 62 miles","sourceChecks":{"0":{"message":"Define `summary(self)` as an instance method on `Car`."}}},"try_methods_and_responsibility_sketch2":{"title":"Add a static validation method","prompt":"Add `@staticmethod` and `is_valid_miles(miles)` to `Car`. It should return `True` when miles is greater than or equal to 0 and `False` otherwise. In `main.py`, call it once from the class with `120` and once from a Car object with `-5`, then print both results.","hint":"A static method uses neither `self` nor `cls`; it receives only the value it checks.","help":{"concept":"A static method is useful for logic related to the class that does not need object state or the class itself.","hint_1":"Place `@staticmethod` above `def is_valid_miles(miles):`.","hint_2":"Return the Boolean expression `miles >= 0`."},"starterCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\n# Print the validation result from the class and from the object.\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\n# Print Car.is_valid_miles(120).\n# Then print car.is_valid_miles(-5).\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n # TODO: add @staticmethod and is_valid_miles(miles).\n"}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\nprint(Car.is_valid_miles(120))\nprint(car.is_valid_miles(-5))\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Toyota\", \"RAV4\", 15000)\n\nprint(Car.is_valid_miles(120))\nprint(car.is_valid_miles(-5))\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n @staticmethod\n def is_valid_miles(miles):\n return miles >= 0\n"}},"checks":{"0":{"message":"Keep the Car class constructible."},"1":{"message":"is_valid_miles should return True for a non-negative value."},"2":{"message":"is_valid_miles should return False for a negative value."},"3":{"message":"Print both validation results."}},"expectedOutput":"True\nFalse"}},"practice":{"mc-methods-and-responsibility-class-jobs":{"title":"Which behavior belongs on Car?","prompt":"Which behaviors naturally belong as instance methods on one `Car` object? Choose all that apply.","hint":"Choose behavior that reads or changes one car's own state.","help":{"concept":"An instance method is a good fit when the behavior belongs to one object's state.","hint_1":"Think about mileage and one-car summaries.","hint_2":"Fleet-wide reports and user menus coordinate more than one object or the whole application."},"options":{"a":"Increase this car's mileage after it drives.","b":"Return a summary of this car's make, model, and mileage.","c":"Build a report across every car in the fleet.","d":"Ask the user which menu option to choose."}},"sc-methods-and-responsibility-main-role":{"title":"Keep display outside the model","prompt":"Which design keeps `Car.summary()` focused on the model's responsibility?","hint":"The method should provide the result; the caller can decide how to display it.","help":{"concept":"Returning a result keeps a model method reusable while `main.py` owns user-facing coordination.","hint_1":"Avoid putting the application's printing policy inside the model.","hint_2":"Choose the option where `summary()` returns and `main.py` prints."},"options":{"a":"`summary()` prints the text itself and returns nothing.","b":"`summary()` returns the text, and `main.py` prints the returned value.","c":"`main.py` rewrites the Car's attributes before every summary.","d":"`summary()` asks the user which car to summarize."}},"fb-methods-and-responsibility-call-name":{"title":"Trace a state-changing method","prompt":"A car starts with `miles = 10000`. After `car.drive(40)` completes, what should `car.miles` be?","hint":"The method adds the driven distance to the object's current mileage.","help":{"concept":"A state-changing instance method updates the object itself.","hint_1":"Start with 10000.","hint_2":"Add 40."},"template":"car.miles == [blank1]","choices":["10040","10000","40","9960"]},"dr-methods-and-responsibility-flow":{"title":"Choose a method by what it needs","prompt":"Put this decision process in order.","hint":"Start by asking what data the behavior needs.","help":{"concept":"The needed context determines the method type.","hint_1":"Object state points to an instance method.","hint_2":"No object or class context points to a static method."},"tokens":{"t1":"Ask whether the behavior needs one object's state","t2":"Use an instance method when it needs `self`","t3":"Use a class method when it needs `cls` or creates objects","t4":"Use a static method when it needs neither"}},"ci-methods-and-responsibility-report-line":{"title":"Build a report line from object methods","prompt":"You are preparing a simple daily report for the account tracker. Finish the `deposit` and `report_line` methods in `models/account.py`. `deposit` should update the balance, and `report_line` should return text in this exact format: `Rae | balance: $95`. `main.py` already creates the account, deposits money, and prints the report line. When you click Run, the output panel should show `Rae | balance: $95`. This matters because the class should both manage state changes and provide account-specific display text.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n pass\n\n def report_line(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n self.balance += amount\n return self.balance\n\n def report_line(self):\n return f\"{self.owner} | balance: ${self.balance}\""}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Rae\", 70)\naccount.deposit(25)\nprint(account.report_line())","checks":{"0":{"message":"Define the Account class."},"1":{"message":"deposit should update the balance to 95."},"2":{"message":"report_line should return the formatted report text."}}},"ci-methods-and-responsibility-validate-withdrawal":{"title":"Keep validation inside the method","prompt":"You are improving the account tracker so invalid withdrawals do not change the balance. In `models/account.py`, finish `withdraw` so it subtracts the amount only when the amount is less than or equal to the current balance. If the amount is too large, leave the balance unchanged. The method should return the current balance after the attempt. `main.py` already prints two results. When you click Run, the output panel should show `60` and then `60`. This matters because validation should live with the object state it protects.","hint":"Check the amount against `self.balance` before subtracting.","help":{"concept":"Encapsulation means the class protects its own state. A withdrawal rule belongs inside the method because the method controls balance changes.","hint_1":"The first call should reduce the balance, but the second call should not make it negative.","hint_2":"Use a conditional inside `withdraw`; only update `self.balance` when the requested amount is allowed, then return the balance either way."},"starterCode":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n self.balance -= amount\n return self.balance"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))"},"models_account_py":{"content":"class Account:\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def withdraw(self, amount):\n if amount <= self.balance:\n self.balance -= amount\n return self.balance"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Jules\", 100)\nprint(account.withdraw(40))\nprint(account.withdraw(80))","checks":{"0":{"message":"Define the Account class."},"1":{"message":"A valid withdrawal should reduce the balance."},"2":{"message":"After an invalid second withdrawal, the balance should remain 60."},"3":{"message":"If the amount is too large, return the unchanged balance."}}},"practice-cart-total-method":{"title":"Put total behavior on the object","prompt":"Define a `Cart` class that stores a list of prices. Add a `total()` method that returns the sum of those prices. Create `Cart([4, 7, 9])` and print `cart.total()`.","hint":"The `Cart` object already owns the price list, so the method should use `self.prices`.","help":{"concept":"A method belongs on an object when the behavior primarily uses and represents that object's own state.","hint_1":"The `Cart` object already owns the price list, so the method should use `self.prices`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n # return the total of this cart\n pass\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n","starterFiles":{"main_py":{"content":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n # return the total of this cart\n pass\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n"}},"solutionCode":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n return sum(self.prices)\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n","solutionFiles":{"main_py":{"content":"class Cart:\n def __init__(self, prices):\n self.prices = prices\n\n def total(self):\n return sum(self.prices)\n\ncart = Cart([4, 7, 9])\nprint(cart.total())\n"}}}}},"module-8-account-tracker-project":{"label":"Module 8 Account Tracker Project","summary":"Build Riverside Club's account tracker so each member balance has one reliable model, safe update rules, and a clear summary.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Account Tracker Build"}},"projectSteps":{"try_module_8_account_tracker_project_sketch0":{"title":"Create the Account model boundary"},"account_tracker_step_2_constructor_attributes":{"title":"Add shared and per-account state"},"account_tracker_step_3_add_methods":{"title":"Add validated account transactions"},"account_tracker_step_4_validation_summary":{"title":"Protect balance and finish the model"}},"moduleProject":{"steps":{"try_module_8_account_tracker_project_sketch0":{"title":"Create the Account model boundary","prompt":"Start the club tracker with the smallest working model boundary. In `models/account.py`, define `class Account:` with `pass` as its body. In `main.py`, import `Account` from `models.account` and create one `Account` object. Do not add state or output yet.","hint":"Keep the reusable class definition in `models/account.py`; `main.py` only imports and uses it.","help":{"concept":"A model file owns the reusable class; main.py imports and uses it.","hint_1":"Define the empty class shell in models/account.py.","hint_2":"Import Account in main.py and call Account() once."},"starterCode":"from models.account import Account\n\n# Create one Account object below.\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\n# Create one Account object below.\n"},"models_account_py":{"content":"# Define the Account class shell below.\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account()\n"},"models_account_py":{"content":"class Account:\n pass\n"}},"solutionCode":"from models.account import Account\n\naccount = Account()\n","checks":{"0":{"message":"Keep `Account` defined in `models/account.py`."},"1":{"message":"The empty `Account` class should be constructible."},"2":{"message":"Create at least one `Account` object in `main.py`."}},"sourceChecks":{"0":{"message":"Define the empty `Account` class shell with `pass` in `models/account.py`."},"1":{"message":"Import the Account model from `models.account` in `main.py`."}}},"account_tracker_step_2_constructor_attributes":{"title":"Add shared and per-account state","prompt":"Continue from the exact previous workspace. In `models/account.py`, replace the empty class body with the class variable `club_name = \"Riverside Club\"` and `__init__(self, owner, balance)`. Store the incoming values on `self.owner` and `self.balance`. In `main.py`, read an owner and integer balance from input, create the account, then print `Account.club_name`, `account.owner`, and `account.balance`, each on its own line.","hint":"The club name is shared class state. Owner and balance belong to each individual account.","help":{"concept":"Class variables hold shared class-level state; self stores per-object state.","hint_1":"Put club_name directly in the class body.","hint_2":"Store owner and balance on self inside __init__."},"starterCode":"from models.account import Account\n\naccount = Account()\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account()\n"},"models_account_py":{"content":"class Account:\n pass\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n"}},"solutionCode":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n","checks":{"0":{"message":"Keep `Account` defined in the model file."},"1":{"message":"Account should be constructible with different owners and balances."},"2":{"message":"Each Account should expose owner and balance state."},"3":{"message":"Create an Account from the input values in `main.py`."},"4":{"message":"Print the shared club name, owner, and balance."}},"expectedOutput":"Riverside Club\nAva\n125","sourceChecks":{"0":{"message":"Define `club_name = \"Riverside Club\"` as class-level state on Account."},"1":{"message":"Define `__init__(self, owner, balance)` on Account."},"2":{"message":"Store the incoming owner on `self.owner`."},"3":{"message":"Store the incoming balance on `self.balance`."}}},"account_tracker_step_3_add_methods":{"title":"Add validated account transactions","prompt":"Continue from the exact previous workspace. In `models/account.py`, add the instance methods `deposit(self, amount)` and `withdraw(self, amount)`. A deposit changes the balance only when `amount > 0`. A withdrawal changes the balance only when `amount > 0` and the amount does not exceed the current balance. Both methods must always return the current balance. In `main.py`, demonstrate a valid deposit, a valid withdrawal, a negative deposit, and an overdraw attempt using the provided values in the solution behavior.","hint":"Keep each validation rule inside the method that owns that state change. Rejected transactions leave the balance unchanged.","help":{"concept":"Instance methods own validated changes to one Account's balance.","hint_1":"deposit accepts only positive amounts.","hint_2":"withdraw also checks that the account has enough balance."},"starterCode":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\nowner = input()\nbalance = int(input())\n\naccount = Account(owner, balance)\n\nprint(Account.club_name)\nprint(account.owner)\nprint(account.balance)\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if amount > 0:\n self.balance += amount\n return self.balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance -= amount\n return self.balance\n"}},"solutionCode":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n","checks":{"0":{"message":"A valid deposit should update and return the new balance."},"1":{"message":"A negative deposit must leave the balance unchanged."},"2":{"message":"A valid withdrawal should update and return the remaining balance."},"3":{"message":"An overdraw attempt must leave the balance unchanged."},"4":{"message":"The methods should preserve correct state on other valid and invalid values too."}},"expectedOutput":"150\n110\n110\n110","sourceChecks":{"0":{"message":"Define `deposit(self, amount)` as an instance method."},"1":{"message":"Define `withdraw(self, amount)` as an instance method."}}},"account_tracker_step_4_validation_summary":{"title":"Protect balance and finish the model","prompt":"Finish the tracker from the exact previous workspace. Refactor `balance` into a validated property backed by `self._balance`. In `__init__`, start the backing value at `0` and route the incoming balance through `self.balance = balance`. Define a `@property` getter `balance(self)` that returns `_balance`, and a `@balance.setter` setter `balance(self, value)` that accepts only values `>= 0`; a negative assignment must leave the current balance unchanged. Keep `deposit()` and `withdraw()` working through the public `balance` property. Add `summary(self)` that returns `CLUB | OWNER: $BALANCE` with two decimal places. Update `main.py` to read the owner, starting balance, a new direct balance, and an invalid direct balance from input; print the starting balance, the accepted balance, the balance after the rejected assignment, then the summary.","hint":"The property gives construction, direct assignment, and the transaction methods one public balance interface while `_balance` remains internal.","help":{"concept":"A property controls direct assignment while preserving normal attribute syntax.","hint_1":"Initialize `_balance` before routing the constructor value through the setter.","hint_2":"summary() returns text; main.py decides to print it."},"starterCode":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n","starterFiles":{"main_py":{"content":"from models.account import Account\n\naccount = Account(\"Ava\", 125)\n\nprint(account.deposit(25))\nprint(account.withdraw(40))\nprint(account.deposit(-5))\nprint(account.withdraw(500))\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self.balance = balance\n\n def deposit(self, amount):\n if amount > 0:\n self.balance += amount\n return self.balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance -= amount\n return self.balance\n"}},"solutionFiles":{"main_py":{"content":"from models.account import Account\n\nowner = input()\nstart_balance = int(input())\nnew_balance = int(input())\ninvalid_balance = int(input())\n\naccount = Account(owner, start_balance)\n\nprint(account.balance)\n\naccount.balance = new_balance\nprint(account.balance)\n\naccount.balance = invalid_balance\nprint(account.balance)\n\nprint(account.summary())\n"},"models_account_py":{"content":"class Account:\n club_name = \"Riverside Club\"\n\n def __init__(self, owner, balance):\n self.owner = owner\n self._balance = 0\n self.balance = balance\n\n @property\n def balance(self):\n return self._balance\n\n @balance.setter\n def balance(self, value):\n if value >= 0:\n self._balance = value\n\n def deposit(self, amount):\n if amount > 0:\n self.balance = self.balance + amount\n return self.balance\n\n def withdraw(self, amount):\n if amount > 0 and amount <= self.balance:\n self.balance = self.balance - amount\n return self.balance\n\n def summary(self):\n return f\"{self.club_name} | {self.owner}: ${self.balance:.2f}\"\n"}},"solutionCode":"from models.account import Account\n\nowner = input()\nstart_balance = int(input())\nnew_balance = int(input())\ninvalid_balance = int(input())\n\naccount = Account(owner, start_balance)\n\nprint(account.balance)\n\naccount.balance = new_balance\nprint(account.balance)\n\naccount.balance = invalid_balance\nprint(account.balance)\n\nprint(account.summary())\n","checks":{"0":{"message":"Account should remain constructible after the property refactor."},"1":{"message":"The public owner and balance state should remain readable."},"2":{"message":"deposit() should still work after the property refactor."},"3":{"message":"withdraw() should still work through the public balance property."},"4":{"message":"summary() should use the actual account state, not the visible example values."}},"expectedOutput":"125\n40\n40\nRiverside Club | Ava: $40.00","sourceChecks":{"0":{"message":"Define `balance` with the `@property` decorator."},"1":{"message":"Define `balance(self, value)` as the property setter."},"2":{"message":"Initialize the internal `_balance` backing value before using the setter."},"3":{"message":"Route the constructor's incoming balance through the public property."},"4":{"message":"Define `summary(self)` on Account."}}}}}},"thinking-in-objects":{"label":"Thinking in Objects","summary":"Use provided objects first so object creation, attributes, and method calls make sense before writing class syntax yourself.","cards":{"course-introduction":{"title":"Course introduction"},"sketch0":{"title":"Create objects"},"sketch1":{"title":"Read attributes"},"sketch2":{"title":"Call methods"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_thinking_in_objects_sketch0":{"title":"Create two objects","prompt":"A `Car` model is already provided in `models/car.py`. In `main.py`, create two separate `Car` objects with sensible make, model, and mileage values. Keep both objects available in variables or a collection. Do not print anything. This exercise is only about creating objects.","hint":"Call `Car(...)` twice. Each constructor call creates a separate object.","help":{"concept":"Calling a class creates an object. Separate constructor calls create separate instances, each with its own state.","hint_1":"The provided constructor accepts a make, a model, and a starting mileage.","hint_2":"Create two `Car(...)` instances and keep both reachable. No output is required."},"starterCode":"from models.car import Car\n\n# A Car model is already provided.\n# Create two Car objects below.\n# Do not print anything yet.","starterFiles":{"main_py":{"content":"from models.car import Car\n\n# A Car model is already provided.\n# Create two Car objects below.\n# Do not print anything yet."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Create two car objects.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncivic_car = Car(\"Honda\", \"Civic\", 12000)\nfocus_car = Car(\"Ford\", \"Focus\", 8000)","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncivic_car = Car(\"Honda\", \"Civic\", 12000)\nfocus_car = Car(\"Ford\", \"Focus\", 8000)"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"Use the provided Car class."},"1":{"message":"Create Car objects with make, model, and miles."},"2":{"message":"Each Car object should keep its own make, model, and miles values."},"3":{"message":"Create at least two Car objects."}},"sourceChecks":{}},"try_thinking_in_objects_sketch1":{"title":"Read attributes from existing objects","prompt":"Two `Car` objects are already created in `main.py`. Use dot notation to print the `make` attribute directly from `corolla_car`, then print the `miles` attribute directly from `mazda_car`, each on its own line. Keep `models/car.py` unchanged.","hint":"Read each requested value from the existing object with dot notation.","help":{"concept":"An attribute is state stored on an object. Dot notation reads that state from a particular instance.","hint_1":"The first value comes from `corolla_car`'s `make` attribute.","hint_2":"The second value comes from `mazda_car`'s `miles` attribute."},"starterCode":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\n# Print the requested attribute from each existing object.\n","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\n# Print the requested attribute from each existing object.\n"},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Read values from car objects.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\nprint(corolla_car.make)\nprint(mazda_car.miles)\n","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncorolla_car = Car(\"Toyota\", \"Corolla\", 22000)\nmazda_car = Car(\"Mazda\", \"3\", 18000)\n\nprint(corolla_car.make)\nprint(mazda_car.miles)\n"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"Use the provided Car class."},"1":{"message":"Create Car objects with make, model, and miles."},"2":{"message":"Each Car object should keep its own make, model, and miles values."},"3":{"message":"Create at least two Car objects."},"4":{"message":"Print the requested attributes on separate lines."}},"expectedOutput":"Toyota\n18000","sourceChecks":{"0":{"message":"Print `corolla_car`'s `make` attribute directly with dot notation."},"1":{"message":"Print `mazda_car`'s `miles` attribute directly with dot notation."}}},"try_thinking_in_objects_sketch2":{"title":"Call methods on an existing object","prompt":"A `car` object is already created in `main.py`. Call `car.drive(50)` to change its mileage. Then print `car.summary()` directly so the output comes from the updated object. Keep `models/car.py` unchanged.","hint":"Change the existing object's state first, then ask that same object to summarize its current state.","help":{"concept":"Methods are behavior attached to objects. A method can change an object's state, and another method can report the updated state.","hint_1":"Use the existing variable `car`; do not create a replacement object.","hint_2":"Call the state-changing method before printing the summary."},"starterCode":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\n\n# Drive the car 50 miles.\n# Then print the updated summary.","starterFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\n\n# Drive the car 50 miles.\n# Then print the updated summary."},"models_car_py":{"content":"# Keep models/car.py unchanged for this step: Call a method on one car object.\nclass Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"solutionCode":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\ncar.drive(50)\n\nprint(car.summary())","solutionFiles":{"main_py":{"content":"from models.car import Car\n\ncar = Car(\"Kia\", \"Soul\", 30000)\ncar.drive(50)\n\nprint(car.summary())"},"models_car_py":{"content":"class Car:\n def __init__(self, make, model, miles):\n self.make = make\n self.model = model\n self.miles = miles\n\n def drive(self, miles):\n self.miles += miles\n return self.miles\n\n def summary(self):\n return f\"{self.make} {self.model} - {self.miles} miles\""}},"checks":{"0":{"message":"Use the provided Car class."},"1":{"message":"After drive(50), summary() should show the updated miles."},"2":{"message":"Create one Car object."},"3":{"message":"Print the updated car summary."}},"expectedOutput":"Kia Soul - 30050 miles","sourceChecks":{"0":{"message":"Call `drive(50)` on the existing `car` object."},"1":{"message":"Print `car.summary()` directly so the output comes from the updated object."}}}},"practice":{"mc-thinking-in-objects-object-idea":{"title":"Why use objects?","prompt":"Which two statements correctly describe objects in this lesson? Choose all that apply.","hint":"Think about one program thing keeping its related values and actions together.","help":{"concept":"An object represents one thing in a program. It can store values and offer methods that work with those values.","hint_1":"Look for choices about grouping related data and behavior.","hint_2":"Reject choices that say all objects share one state or that objects are only about printing output."},"options":{"a":"Objects help model things the program cares about.","b":"An object can keep related values and useful behavior together.","c":"Every object from one class must share the exact same state forever.","d":"Objects are only useful when the program prints text."}},"sc-thinking-in-objects-attribute-meaning":{"title":"What is an attribute?","prompt":"In this topic, what does an attribute mean?","hint":"Think about values like a car's make, model, or miles.","help":{"concept":"An attribute is a value stored on one specific object.","hint_1":"Dot notation reads an attribute from an object.","hint_2":"Choose the answer about a value stored on one object."},"options":{"a":"A value stored on a specific object.","b":"A file that always runs before main.py.","c":"A kind of loop.","d":"A comment that explains a class."}},"fb-thinking-in-objects-method-call":{"title":"Trace a method change","prompt":"A `Car` object starts with `miles = 30000`. The program calls `car.drive(50)`. What should `car.miles` be afterward?","hint":"The method adds the traveled distance to the object's current mileage.","help":{"concept":"A state-changing method updates data stored on the object.","hint_1":"Start with 30000 and add 50.","hint_2":"The updated mileage is 30050."},"options":{"a":"30000","b":"30050","c":"50","d":"29950"}},"dr-thinking-in-objects-workflow":{"title":"Order the object workflow","prompt":"Put these steps in the usual order for working with an object.","hint":"Start by creating the object before reading or changing it.","help":{"concept":"A clear object workflow is: create an object, read attributes when needed, call methods when behavior is needed, then print or use the result.","hint_1":"An object must exist before you can read from it.","hint_2":"Printing the result comes after the object is created and updated."},"tokens":{"t1":"Create the object with starting values","t2":"Read an attribute from the object","t3":"Call a method on that object","t4":"Print or use the object's current state"}},"practice-book-object-description":{"title":"Create an object with its own data","prompt":"Define a `Book` class whose constructor stores `title` and `pages`. Add a `description()` method that returns `<title> - <pages> pages`. Create `Book(\"Orbit\", 240)` and print its description.","hint":"Store the constructor arguments on `self`, then let the method read those attributes.","help":{"concept":"An object bundles related state with behavior that uses that state.","hint_1":"Store the constructor arguments on `self`, then let the method read those attributes.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Book:\n def __init__(self, title, pages):\n # store both values\n pass\n\n def description(self):\n # return the formatted description\n pass\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n","starterFiles":{"main_py":{"content":"class Book:\n def __init__(self, title, pages):\n # store both values\n pass\n\n def description(self):\n # return the formatted description\n pass\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n"}},"solutionCode":"class Book:\n def __init__(self, title, pages):\n self.title = title\n self.pages = pages\n\n def description(self):\n return f\"{self.title} - {self.pages} pages\"\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n","solutionFiles":{"main_py":{"content":"class Book:\n def __init__(self, title, pages):\n self.title = title\n self.pages = pages\n\n def description(self):\n return f\"{self.title} - {self.pages} pages\"\n\nbook = Book(\"Orbit\", 240)\nprint(book.description())\n"}}},"practice-two-pet-instances":{"title":"Keep separate state in two objects","prompt":"Define a `Pet` class that stores `name` and `sound`, with a `speak()` method returning `<name>: <sound>`. Create `Pet(\"Milo\", \"meow\")` and `Pet(\"Rex\", \"woof\")`, then print both `speak()` results.","hint":"Each instance should store its own `name` and `sound` attributes.","help":{"concept":"Different instances of the same class keep separate state while sharing the same method definitions.","hint_1":"Each instance should store its own `name` and `sound` attributes.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Pet:\n def __init__(self, name, sound):\n pass\n\n def speak(self):\n pass\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n","starterFiles":{"main_py":{"content":"class Pet:\n def __init__(self, name, sound):\n pass\n\n def speak(self):\n pass\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n"}},"solutionCode":"class Pet:\n def __init__(self, name, sound):\n self.name = name\n self.sound = sound\n\n def speak(self):\n return f\"{self.name}: {self.sound}\"\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n","solutionFiles":{"main_py":{"content":"class Pet:\n def __init__(self, name, sound):\n self.name = name\n self.sound = sound\n\n def speak(self):\n return f\"{self.name}: {self.sound}\"\n\nfirst = Pet(\"Milo\", \"meow\")\nsecond = Pet(\"Rex\", \"woof\")\nprint(first.speak())\nprint(second.speak())\n"}}},"practice-task-state-method":{"title":"Let a method change object state","prompt":"Define a `Task` class that stores `title` and starts with `done = False`. Add `complete()` so it sets `done` to `True`. Create one task, call `complete()`, and print its `title` and `done` value on separate lines.","hint":"The method should update `self.done` on the existing object.","help":{"concept":"Methods can change the state stored on an object, allowing the object to manage related data and behavior together.","hint_1":"The method should update `self.done` on the existing object.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Task:\n def __init__(self, title):\n # store title and start done as False\n pass\n\n def complete(self):\n # mark this task complete\n pass\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n","starterFiles":{"main_py":{"content":"class Task:\n def __init__(self, title):\n # store title and start done as False\n pass\n\n def complete(self):\n # mark this task complete\n pass\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n"}},"solutionCode":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n self.done = True\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n","solutionFiles":{"main_py":{"content":"class Task:\n def __init__(self, title):\n self.title = title\n self.done = False\n\n def complete(self):\n self.done = True\n\ntask = Task(\"Submit report\")\ntask.complete()\nprint(task.title)\nprint(task.done)\n"}}}}}},"python-9-inheritance-polymorphism-and-abstraction":{"abstraction-with-base-interfaces":{"label":"Abstract Base Classes and Interfaces","summary":"Use `ABC` and `@abstractmethod` to make a shared method requirement enforceable, then make a subclass concrete by implementing that method.","cards":{"sketch0":{"title":"Define an enforceable contract"},"sketch1":{"title":"Make a child concrete"},"sketch2":{"title":"Program to shared behavior"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_abstraction_with_base_interfaces_sketch0":{"title":"Make CatalogItem an abstract contract","prompt":"`main.py` is already complete. In `models/catalog_item.py`, import `ABC` and `abstractmethod` from `abc`, make `CatalogItem` inherit from `ABC`, and decorate `label(self)` with `@abstractmethod`. Keep the existing constructor that stores `title`. Leave `main.py` unchanged.","hint":"The class must use `ABC`, and the required `label()` method needs the `@abstractmethod` decorator.","help":{"concept":"An abstract base class can enforce that related concrete subclasses implement a required method.","hint_1":"Import both `ABC` and `abstractmethod` from `abc`.","hint_2":"Place `@abstractmethod` directly above `label(self)`."},"starterCode":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n"},"models_catalog_item_py":{"content":"# Import ABC and abstractmethod from abc.\n\nclass CatalogItem:\n def __init__(self, title):\n self.title = title\n\n # Make label() an abstract method.\n def label(self):\n pass\n"},"models_book_py":{"content":"# Book is used in the next step; leave it unchanged for now.\n"}},"solutionCode":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n","solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass IncompleteItem(CatalogItem):\n pass\n\n\nclass CompleteItem(CatalogItem):\n def label(self):\n return self.title\n\n\nfor item_class, name in (\n (CatalogItem, \"CatalogItem\"),\n (IncompleteItem, \"IncompleteItem\"),\n):\n try:\n item_class(\"Blocked\")\n except TypeError:\n print(f\"{name} blocked\")\n\nprint(CompleteItem(\"Ready\").label())\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"# Book is used in the next step.\n"}},"checks":{"0":{"message":"Define CatalogItem in models/catalog_item.py."},"1":{"message":"CatalogItem should be abstract so Python refuses to instantiate it."}},"expectedOutput":"CatalogItem blocked\nIncompleteItem blocked\nReady","sourceChecks":{"0":{"message":"Import both `ABC` and `abstractmethod` from Python's `abc` module."},"1":{"message":"Make `CatalogItem` inherit from `ABC`."},"2":{"message":"Decorate `label(self)` with `@abstractmethod`."}}},"try_abstraction_with_base_interfaces_sketch1":{"title":"Fulfill the abstract contract in Book","prompt":"`CatalogItem` is already abstract and its constructor already stores `title`. In `models/book.py`, keep `Book` inheriting from `CatalogItem` and implement the required `label(self)` method so it returns `Book: ` followed by that object's title. Do not add another constructor; `Book` should inherit the parent's constructor. Leave `models/catalog_item.py` and `main.py` unchanged.","hint":"Implement the required method directly on `Book`. Once `label()` exists, Python can instantiate the child.","help":{"concept":"A subclass remains abstract until it implements every required abstract method. Shared constructor setup can still be inherited.","hint_1":"Keep `class Book(CatalogItem)`.","hint_2":"Define only `label(self)` and use the inherited `self.title`."},"starterCode":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n # Implement the required label() method.\n pass\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n # TODO: return Movie: <title>.\n pass\n"}},"solutionCode":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n","solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n\ntry:\n CatalogItem(title)\nexcept TypeError:\n print(\"CatalogItem blocked\")\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"`Book.label()` should use the object's actual inherited title."},"1":{"message":"`Book.label()` should work for other valid titles too."},"2":{"message":"Print both concrete labels."}},"expectedOutput":"Book: Coraline\nCatalogItem blocked","sourceChecks":{"0":{"message":"Keep `Book` inheriting from the abstract `CatalogItem` contract."},"1":{"message":"Implement the required `label(self)` method on `Book`."}}},"try_abstraction_with_base_interfaces_sketch2":{"title":"Use a helper that trusts the interface","prompt":"Complete `show_labels(items)` in `services/catalog_view.py`. Return one string with each item's `label()` on its own line. The helper does not need `isinstance` checks; it depends only on the shared behavior. `main.py` is already wired to print the returned string.","hint":"Collect each `item.label()` result and join them with `\"\\n\"`.","help":{"concept":"The ABC enforces the contract for this family of classes. The helper itself uses Python's duck-typing style: it only needs each object to provide `label()`.","hint_1":"Use `\"\\n\".join(...)` so there is no extra blank line.","hint_2":"Do not print inside the helper; return one string."},"starterCode":"# Run this provided script after completing show_labels.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n","starterFiles":{"main_py":{"content":"# Run this provided script after completing show_labels.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_view_py":{"content":"def show_labels(items):\n # TODO: return one string with each item.label() on its own line.\n pass\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_view import show_labels\n\nitems = [Book(\"Dune\"), Movie(\"Moana\")]\nprint(show_labels(items))\n"},"models_catalog_item_py":{"content":"from abc import ABC, abstractmethod\n\nclass CatalogItem(ABC):\n def __init__(self, title):\n self.title = title\n\n @abstractmethod\n def label(self):\n pass\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def __init__(self, title):\n super().__init__(title)\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_view_py":{"content":"def show_labels(items):\n return \"\\n\".join(item.label() for item in items)\n"}},"checks":{"0":{"message":"Return both labels so main.py prints two lines."}},"expectedOutput":"Book: Dune\nMovie: Moana"}},"practice":{"sc-interface-purpose":{"title":"What does the abstract contract enforce?","prompt":"What does `ABC` together with `@abstractmethod` add to `CatalogItem`?","hint":"Think about what Python prevents when required behavior is missing.","help":{"concept":"An abstract base class can prevent incomplete classes from being instantiated.","hint_1":"The contract is about required behavior.","hint_2":"Concrete subclasses can still implement that behavior differently."},"options":{"a":"Python blocks instantiation while a required abstract method is unresolved.","b":"Every subclass must return exactly the same label text.","c":"The abstract parent can no longer store shared state.","d":"Subclasses are no longer allowed to inherit methods."}},"fb-interface-method-name":{"title":"Mark the required method","prompt":"Complete the decorator that marks `label()` as required.","hint":"It comes from Python's `abc` module.","help":{"concept":"`@abstractmethod` marks behavior that concrete subclasses must implement.","hint_1":"The decorator begins with `@`.","hint_2":"Its name combines `abstract` and `method`."},"template":"[blank1]\ndef label(self):\n pass","choices":["@abstractmethod","@staticmethod","@classmethod","@property"]},"dr-interface-build-order":{"title":"Order the ABC workflow","prompt":"Put these steps in a clear order.","hint":"Declare the contract before creating concrete child objects.","help":{"concept":"Import the ABC tools, define the abstract parent, implement the method in children, then use the objects through shared behavior.","hint_1":"Imports come first.","hint_2":"The helper comes after concrete implementations exist."},"tokens":{"t1":"Import `ABC` and `abstractmethod`","t2":"Define the abstract method on the base class","t3":"Implement the method in each concrete child","t4":"Call the shared method from a helper"}},"sc-interface-helper-focus":{"title":"What happens to an incomplete child?","prompt":"`CatalogItem.label()` is abstract. `DraftItem(CatalogItem)` does not implement `label()`. What happens when code tries to create `DraftItem(\"Notes\")`?","hint":"The child still has an unresolved abstract method.","help":{"concept":"A subclass remains abstract until it implements every required abstract method.","hint_1":"Inheritance alone does not make the child concrete.","hint_2":"Python blocks construction of an incomplete child."},"options":{"a":"Python creates the object and uses `pass` as its label.","b":"Python raises `TypeError` because the child is still abstract.","c":"Python automatically copies a `label()` implementation into the child.","d":"Python removes `CatalogItem` from the inheritance chain."}},"ci-catalog-add-audio-subclass":{"title":"Add an audio item that fits the contract","prompt":"The catalog is expanding again. Add an `Audio` subclass that fits the same base-class contract used by the report service.\n\nTasks:\n- In `models/audio.py`, create `Audio(BaseItem)`.\n- Its constructor should accept `title` and `speaker`, call `super().__init__(title)`, and store `speaker`.\n- Override `display_line()` to return `Audio: <title> by <speaker>`.\n- Do not change `services/report_service.py` or `main.py`.\n\nClick Run and confirm the output panel shows lines for a book, a video, and the new audio item.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def display_line(self):\n return self.title\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_line(self):\n return f\"Book: {self.title} by {self.author}\"\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_line(self):\n return f\"Video: {self.title} ({self.minutes} min)\"\n"},"models_audio_py":{"content":"from models.base_item import BaseItem\n\nclass Audio(BaseItem):\n def __init__(self, title, speaker):\n pass\n\n def display_line(self):\n pass\n"},"services_report_service_py":{"content":"def build_report(items):\n lines = []\n for item in items:\n lines.append(item.display_line())\n return lines\n"}},"solutionCode":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom models.audio import Audio\nfrom services.report_service import build_report\n\nitems = [\n Book(\"Atomic Habits\", \"James Clear\"),\n Video(\"Study Skills\", 15),\n Audio(\"Focus Session\", \"Maya Lee\")\n]\n\nfor line in build_report(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def display_line(self):\n return self.title\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_line(self):\n return f\"Book: {self.title} by {self.author}\"\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_line(self):\n return f\"Video: {self.title} ({self.minutes} min)\"\n"},"models_audio_py":{"content":"from models.base_item import BaseItem\n\nclass Audio(BaseItem):\n def __init__(self, title, speaker):\n super().__init__(title)\n self.speaker = speaker\n\n def display_line(self):\n return f\"Audio: {self.title} by {self.speaker}\"\n"},"services_report_service_py":{"content":"def build_report(items):\n lines = []\n for item in items:\n lines.append(item.display_line())\n return lines\n"}},"checks":{"0":{"message":"Define the Audio class."},"1":{"message":"Audio should be constructible with title and speaker."},"2":{"message":"Audio should store title and speaker."},"3":{"message":"Audio.display_line() should match the shared report contract."}}},"ci-catalog-baseitem-checkout":{"title":"Add a checkout message contract","prompt":"Practice a shared checkout-message contract in a small media catalog. In `models/base_item.py`, add `checkout_message()` that returns `<title> is ready`. In `models/book.py`, override it to return `Borrow book: <title>`. In `models/video.py`, override it to return `Play video: <title>`. Keep `services/checkout_service.py` generic so it loops through mixed objects and calls the shared method.","hint":"Read the task \"Add a checkout message contract\" and identify the required result.","help":{"concept":"This coding exercise checks whether your code produces the requested result for: \"Add a checkout message contract\".","hint_1":"Use the statement or expression that matches the required behavior in the code editor.","hint_2":"Click Run and compare the output panel with the expected result."},"starterCode":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def checkout_message(self):\n pass\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def checkout_message(self):\n pass\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def checkout_message(self):\n pass\n"},"services_checkout_service_py":{"content":"def collect_messages(items):\n messages = []\n for item in items:\n messages.append(item.checkout_message())\n return messages\n"}},"solutionCode":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.checkout_service import collect_messages\n\nitems = [Book(\"Dune\", \"Frank Herbert\"), Video(\"Safety Training\", 12)]\nfor line in collect_messages(items):\n print(line)\n"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def checkout_message(self):\n return f\"{self.title} is ready\"\n"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def checkout_message(self):\n return f\"Borrow book: {self.title}\"\n"},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def checkout_message(self):\n return f\"Play video: {self.title}\"\n"},"services_checkout_service_py":{"content":"def collect_messages(items):\n messages = []\n for item in items:\n messages.append(item.checkout_message())\n return messages\n"}},"checks":{"0":{"message":"BaseItem.checkout_message() should return the generic message."},"1":{"message":"Book.checkout_message() should return the book-specific message."},"2":{"message":"Video.checkout_message() should return the video-specific message."}}},"ci-catalog-export-labels":{"title":"Build export labels from mixed items","prompt":"The catalog app now needs export labels for storage. Finish the service so it works with mixed objects through the shared contract.\n\nTasks:\n- Keep `export_label()` in the base class and both subclasses.\n- In `services/export_service.py`, complete `join_labels(items)` so it returns one string with labels joined by ` | `.\n- The service must call `item.export_label()` on each object in the list.\n\nDo not change `main.py`. Click Run and check the output panel for the joined label string.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def export_label(self):\n return self.title"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def export_label(self):\n return f\"BOOK-{self.title}\""},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def export_label(self):\n return f\"VIDEO-{self.title}\""},"services_export_service_py":{"content":"def join_labels(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))"},"models_base_item_py":{"content":"class BaseItem:\n def __init__(self, title):\n self.title = title\n\n def export_label(self):\n return self.title"},"models_book_py":{"content":"from models.base_item import BaseItem\n\nclass Book(BaseItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def export_label(self):\n return f\"BOOK-{self.title}\""},"models_video_py":{"content":"from models.base_item import BaseItem\n\nclass Video(BaseItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def export_label(self):\n return f\"VIDEO-{self.title}\""},"services_export_service_py":{"content":"def join_labels(items):\n labels = []\n for item in items:\n labels.append(item.export_label())\n return \" | \".join(labels)"}},"solutionCode":"from models.book import Book\nfrom models.video import Video\nfrom services.export_service import join_labels\n\nitems = [Book(\"Refactoring\", \"Martin Fowler\"), Video(\"Git Basics\", 25)]\nprint(join_labels(items))","checks":{"0":{"message":"join_labels() should join export labels from mixed items in order."}}}}},"inheritance-for-shared-behavior":{"label":"Inheritance for Shared Behavior","summary":"Use a parent class for genuinely shared state and behavior, then call `super().__init__` when a child constructor adds specialized state.","cards":{"sketch0":{"title":"Inherit shared setup and behavior"},"sketch1":{"title":"Add child state with super()"},"sketch2":{"title":"Extend a parent method"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_inheritance_for_shared_behavior_sketch0":{"title":"Make Book inherit shared behavior","prompt":"`CatalogItem` already owns the shared `title` constructor and `label()` method. In `models/book.py`, make `Book` inherit from `CatalogItem`. Do not add a `Book.__init__` or `Book.label()` yet; this exercise is about reusing the parent's existing setup and behavior. Leave `main.py` and `models/catalog_item.py` unchanged.","hint":"Put the parent class in parentheses in the `Book` class header.","help":{"concept":"A child class inherits available parent behavior. With no child constructor or label method, `Book` can use the parent's versions.","hint_1":"The parent class is `CatalogItem`.","hint_2":"Change only the `Book` class header; keep the body as `pass`."},"starterCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n# Make Book inherit from CatalogItem.\nclass Book:\n pass\n"}},"solutionCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n pass\n"}},"checks":{"0":{"message":"Keep `Book` defined in `models/book.py`."},"1":{"message":"The inherited parent constructor should make `Book(title)` constructible."},"2":{"message":"A `Book` should inherit the parent's `title` state."},"3":{"message":"A `Book` should inherit the parent's `label()` behavior."}},"expectedOutput":"Dune","sourceChecks":{"0":{"message":"Make `Book` inherit from `CatalogItem` in the class header."}}},"try_inheritance_for_shared_behavior_sketch1":{"title":"Add Book-specific state with super()","prompt":"`Book` already inherits from `CatalogItem`. In `models/book.py`, define `__init__(self, title, author)`. Call `super().__init__(title)` so the parent owns the shared title setup, then store the Book-specific author on `self.author`. Do not duplicate `self.title = title` inside `Book`. Leave `main.py` and `models/catalog_item.py` unchanged.","hint":"Let the parent initialize the shared title first, then store only the child-specific author.","help":{"concept":"`super().__init__` lets a child constructor reuse parent setup instead of copying the parent's initialization logic.","hint_1":"Call the parent constructor with the shared `title` value.","hint_2":"After the super call, assign `author` to `self.author`."},"starterCode":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n # Call the parent constructor for the shared title setup.\n # Then store the Book-specific author.\n pass\n"}},"solutionCode":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nauthor = input()\nbook = Book(title, author)\n\nprint(book.title)\nprint(book.author)\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n"}},"checks":{"0":{"message":"Keep `Book` defined in `models/book.py`."},"1":{"message":"`Book` should accept both shared title and child-specific author state."},"2":{"message":"The finished `Book` should contain both inherited title and author state."},"3":{"message":"The constructor should work for other valid book data too."},"4":{"message":"Inherited and child-specific state should remain available on unseen data."}},"expectedOutput":"The Martian\nAndy Weir","sourceChecks":{"0":{"message":"Keep `Book` inheriting from `CatalogItem`."},"1":{"message":"Call `super().__init__(title)` for the shared parent setup."},"2":{"message":"Store the child-specific `author` on `self.author`."}}},"try_inheritance_for_shared_behavior_sketch2":{"title":"Extend a parent method with super()","prompt":"Add `label(self)` to `Book`. Start with `base_label = super().label()`, then return `f\"{base_label} by {self.author}\"`. In `main.py`, create `Book(\"The Hobbit\", \"J. R. R. Tolkien\")` and print its label.","hint":"Call `super().label()` to reuse the parent result before adding the author.","help":{"concept":"A child can override a method and still reuse the parent implementation. `super().label()` gets the parent result; the child adds its specialized detail.","hint_1":"Keep the Book constructor that calls `super().__init__(title)`.","hint_2":"Return the parent label followed by ` by ` and the author."},"starterCode":"from models.book import Book\n\n# Create The Hobbit and print the extended label.\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\n# Create Book(\"The Hobbit\", \"J. R. R. Tolkien\").\n# Print book.label().\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def label(self):\n # TODO: reuse the parent label and add the author.\n pass\n"}},"solutionCode":"from models.book import Book\n\nbook = Book(\"The Hobbit\", \"J. R. R. Tolkien\")\nprint(book.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\nbook = Book(\"The Hobbit\", \"J. R. R. Tolkien\")\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def label(self):\n base_label = super().label()\n return f\"{base_label} by {self.author}\"\n"}},"checks":{"0":{"message":"Book should accept title and author."},"1":{"message":"Book.label() should extend the parent label with the author."},"2":{"message":"Create the Book object in main.py."},"3":{"message":"Print the extended label."}},"expectedOutput":"The Hobbit by J. R. R. Tolkien"}},"practice":{"sc-inheritance-shared-work":{"title":"When does a parent class help?","prompt":"When is inheritance a good fit for shared setup?","hint":"Use a parent for behavior or state that is genuinely common to related child classes.","help":{"concept":"Inheritance is useful when related classes can reuse meaningful shared state or behavior.","hint_1":"The shared code should belong naturally to the parent concept.","hint_2":"Do not introduce inheritance just to avoid a few unrelated lines."},"options":{"a":"Whenever two unrelated classes happen to contain the same number of lines.","b":"When related classes genuinely share state or behavior that belongs in one parent.","c":"Whenever every child must eventually produce identical output.","d":"Only when no objects will ever be created."}},"fb-inheritance-subclass-name":{"title":"Reuse the parent constructor","prompt":"Complete the child constructor so it delegates the shared `title` setup to the parent.","hint":"Use the function that gives access to the next implementation in the inheritance chain.","help":{"concept":"`super()` lets the child reuse parent initialization without naming or copying the parent implementation.","hint_1":"The call is followed by `.__init__(title)`.","hint_2":"Include the parentheses in `super()`."},"template":"[blank1].__init__(title)","choices":["super()","self","CatalogItem()","parent"]},"dr-inheritance-build-order":{"title":"Order a child constructor","prompt":"Put these steps in a clear order.","hint":"Connect the child to the parent before adding child-only state.","help":{"concept":"The child class inherits first, then its constructor calls the parent setup, then it stores specialized state.","hint_1":"The class header comes first.","hint_2":"Call super before using the completed object."},"tokens":{"t1":"Define the child class with the parent in parentheses","t2":"Define the child constructor","t3":"Call `super().__init__(...)` for shared setup","t4":"Store the child-specific attributes"}},"sc-inheritance-method-reuse":{"title":"Place shared and specialized state","prompt":"`CatalogItem` stores `title`, while only `Book` has an `author`. Which design best matches those responsibilities?","hint":"Put genuinely shared state on the parent and child-only state on the child.","help":{"concept":"A parent owns shared state; a child adds only the state or behavior that makes it more specific.","hint_1":"Every catalog item needs a title.","hint_2":"Only books need the author field in this example."},"options":{"a":"Store both title and author only on `CatalogItem`, even for non-books.","b":"Store title independently in every child and leave the parent empty.","c":"Let `CatalogItem` initialize title, then let `Book` add author after calling `super().__init__(title)`.","d":"Put both values in `main.py` and keep them off the objects."}},"ci-inheritance-mixed-count-service":{"title":"Count mixed catalog items with one shared method","prompt":"You are building a quick inventory summary. `Book` and `Movie` should both inherit from `CatalogItem`, and `CatalogItem` should define `is_available()` that returns `True` when `stock > 0`. In `services/inventory_service.py`, complete `count_available(items)` so it returns how many objects in the mixed list are available. In `main.py`, use `Book(\"Dune\", 3)` and `Movie(\"Arrival\", 0)` and print the count. This matters because one shared base method lets a service work across different subclasses.","hint":"Give both subclasses the same inherited availability rule, then count how many return `True`.","help":{"concept":"A shared base-class method creates a common contract for subclasses. Services can then loop through mixed objects and call the same method on each one.","hint_1":"`is_available()` should check the stored `stock` value in the base class.","hint_2":"In the service function, increase the count only when `item.is_available()` is true."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title, stock):\n self.title = title\n self.stock = stock\n\n def is_available(self):\n return self.stock > 0"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n pass"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n pass"},"services_inventory_service_py":{"content":"def count_available(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title, stock):\n self.title = title\n self.stock = stock\n\n def is_available(self):\n return self.stock > 0"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n pass"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n pass"},"services_inventory_service_py":{"content":"def count_available(items):\n return sum(1 for item in items if item.is_available())"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.inventory_service import count_available\n\nitems = [Book(\"Dune\", 3), Movie(\"Arrival\", 0)]\nprint(count_available(items))","checks":{"0":{"message":"Book should inherit is_available() and return True when stock is above zero."},"1":{"message":"Movie should inherit is_available() and return False when stock is zero."},"2":{"message":"count_available(items) should count available objects in a mixed list."}}},"ci-inheritance-shared-price-method":{"title":"Share a discount method through inheritance","prompt":"You are updating prices in a shop catalog. In `models/base_item.py`, complete `CatalogItem` so it stores `title` and `price`, and add `discounted_price(percent)` that returns the reduced price. In `models/book.py`, make `Book` inherit from `CatalogItem` and add `author`. In `main.py`, create `Book(\"Clean Code\", 30, \"Robert C. Martin\")` and print the result of `discounted_price(20)`. This matters because shared business rules belong in the base class instead of being copied into every subclass.","hint":"Use the lesson explanation and the wording of this question to narrow the answer.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n"},"models_base_item_py":{"content":"class CatalogItem:\n def __init__(self, title, price):\n pass\n\n def discounted_price(self, percent):\n pass\n"},"models_book_py":{"content":"from models.base_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, price, author):\n pass\n"}},"solutionCode":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\nbook = Book(\"Clean Code\", 30, \"Robert C. Martin\")\nprint(book.discounted_price(20))\n"},"models_base_item_py":{"content":"class CatalogItem:\n def __init__(self, title, price):\n self.title = title\n self.price = price\n\n def discounted_price(self, percent):\n return self.price * (1 - percent / 100)\n"},"models_book_py":{"content":"from models.base_item import CatalogItem\n\nclass Book(CatalogItem):\n def __init__(self, title, price, author):\n super().__init__(title, price)\n self.author = author\n"}},"sourceChecks":{"0":{"message":"Make `Book` inherit from `CatalogItem` in the class header."}},"checks":{"0":{"message":"Define CatalogItem in models/base_item.py."},"1":{"message":"Define Book in models/book.py."},"2":{"message":"A Book should inherit discounted_price() from CatalogItem and calculate the reduced price correctly."}}},"practice-inherit-shared-label":{"title":"Inherit a shared label method","prompt":"Define a base class `Vehicle` that stores `name` and has `label()` returning `Vehicle: <name>`. Define `Bike(Vehicle)` without rewriting `label()`. Create `Bike(\"Comet\")` and print its inherited label.","hint":"The subclass can use the base constructor and method without defining them again.","help":{"concept":"Inheritance lets a subclass reuse behavior that is genuinely shared with its base class.","hint_1":"The subclass can use the base constructor and method without defining them again.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class Vehicle:\n def __init__(self, name):\n # store the shared name\n pass\n\n def label(self):\n # return Vehicle: <name>\n pass\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n","starterFiles":{"main_py":{"content":"class Vehicle:\n def __init__(self, name):\n # store the shared name\n pass\n\n def label(self):\n # return Vehicle: <name>\n pass\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n"}},"solutionCode":"class Vehicle:\n def __init__(self, name):\n self.name = name\n\n def label(self):\n return f\"Vehicle: {self.name}\"\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n","solutionFiles":{"main_py":{"content":"class Vehicle:\n def __init__(self, name):\n self.name = name\n\n def label(self):\n return f\"Vehicle: {self.name}\"\n\nclass Bike(Vehicle):\n pass\n\nbike = Bike(\"Comet\")\nprint(bike.label())\n"}}}}},"module-9-greenhouse-sensor-project":{"label":"Module 9 Greenhouse Sensor Project","summary":"Build a greenhouse monitor that lets temperature and humidity sensors share one contract and one reporting flow.","cards":{"sketch0":{"title":"Project story"},"project":{"title":"Greenhouse Sensor Monitor"}},"projectSteps":{"greenhouse_project_step_1_base_and_temperature":{"title":"Milestone 1: Build the Sensor contract"},"greenhouse_project_step_2_add_humidity_override":{"title":"Milestone 2: Add HumiditySensor"},"greenhouse_project_step_3_mixed_sensor_loop":{"title":"Milestone 3: Use one polymorphic sensor loop"},"greenhouse_project_step_4_monitor_class_report":{"title":"Milestone 4: Give the monitor collection ownership"}},"moduleProject":{"steps":{"greenhouse_project_step_1_base_and_temperature":{"title":"Milestone 1: build the abstract Sensor contract","prompt":"Complete the first greenhouse milestone. In `models/sensor.py`, make `Sensor` inherit from `ABC`, keep the constructor that stores `zone`, and make `reading(self)` an `@abstractmethod`. In `models/temperature_sensor.py`, keep `TemperatureSensor(Sensor)`, call `super().__init__(zone)`, store `celsius`, and implement `reading()` so it returns `Temperature: <zone> = <value> C`. In `main.py`, create the sensor from the provided input values and print its reading. Leave the future humidity/monitor placeholder files unchanged.","hint":"Retrieve the patterns from the inheritance and ABC lessons: the parent owns shared `zone` setup; the concrete child supplies `reading()`.","help":{"concept":"This milestone combines an enforceable abstract contract with shared parent setup and one concrete implementation.","hint_1":"Import `ABC` and `abstractmethod` from `abc`.","hint_2":"Use `super().__init__(zone)` instead of copying `self.zone = zone` into the child."},"starterCode":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\n# Create the TemperatureSensor and print its reading.\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\n# Create the TemperatureSensor and print its reading.\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"# Make Sensor an abstract base class with a required reading() method.\nclass Sensor:\n def __init__(self, zone):\n self.zone = zone\n\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n # Reuse Sensor's zone setup, then store celsius.\n pass\n\n def reading(self):\n # Return: Temperature: <zone> = <celsius> C\n pass\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"}},"checks":{"0":{"message":"TemperatureSensor should be concrete and constructible."},"1":{"message":"Keep shared `zone` state and child-specific `celsius` state."},"2":{"message":"TemperatureSensor.reading() must use the object's actual state."},"3":{"message":"TemperatureSensor.reading() must work for other valid readings."},"4":{"message":"TemperatureSensor should accept zone and celsius."},"5":{"message":"TemperatureSensor should store its state and return the expected reading."}},"expectedOutput":"Temperature: North Bed = 21.5 C","sourceChecks":{"0":{"message":"Import both `ABC` and `abstractmethod` from `abc`."},"1":{"message":"Make `Sensor` inherit from `ABC`."},"2":{"message":"Make `reading(self)` an abstract method."},"3":{"message":"Keep `TemperatureSensor` inheriting from `Sensor`."},"4":{"message":"Reuse the parent constructor with `super().__init__(zone)`."},"5":{"message":"Implement the concrete `reading(self)` method."}}},"greenhouse_project_step_2_add_humidity_override":{"title":"Milestone 2: add a second concrete sensor","prompt":"Continue from the exact Milestone 1 workspace. Complete `models/humidity_sensor.py` with `HumiditySensor(Sensor)`. Its constructor must call `super().__init__(zone)` and store `percent`; `reading(self)` must return `Humidity: <zone> = <percent>%`. Update `main.py` to read the provided temperature and humidity values, create both sensor objects, and print both readings. Keep the existing `Sensor` and `TemperatureSensor` implementations unchanged.","hint":"HumiditySensor follows the same inherited setup contract as TemperatureSensor, but owns different child state and output.","help":{"concept":"Sibling subclasses can reuse the same parent setup while specializing the same required method.","hint_1":"Use `class HumiditySensor(Sensor)`.","hint_2":"Call `super().__init__(zone)` before storing `percent`."},"starterCode":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\n\nzone = input()\ncelsius = float(input())\n\nsensor = TemperatureSensor(zone, celsius)\nprint(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"# Added in Milestone 2.\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"}},"checks":{"0":{"message":"Keep the completed TemperatureSensor behavior working."},"1":{"message":"HumiditySensor should be concrete and constructible."},"2":{"message":"Keep shared `zone` state and child-specific `percent` state."},"3":{"message":"HumiditySensor.reading() must use the object's actual state."},"4":{"message":"HumiditySensor.reading() must work for other valid readings."}},"expectedOutput":"Temperature: North Bed = 21.5 C\nHumidity: Seedling Bench = 64%","sourceChecks":{"0":{"message":"Make `HumiditySensor` inherit from `Sensor`."},"1":{"message":"Reuse the shared parent setup with `super().__init__(zone)`."},"2":{"message":"Implement the humidity-specific `reading(self)` method."}}},"greenhouse_project_step_3_mixed_sensor_loop":{"title":"Milestone 3: use one polymorphic sensor loop","prompt":"Continue from the exact Milestone 2 workspace. In `main.py`, replace the two separate sensor variables/print calls with one `sensors` list containing the `TemperatureSensor` and `HumiditySensor`. Use one `for` loop over `sensors` and call the current object's shared `reading()` method. Do not branch with `isinstance()`, `type()`, `__class__`, or separate Temperature/Humidity cases. Keep all model files unchanged.","hint":"The caller should trust the `reading()` contract instead of asking which sensor subclass it received.","help":{"concept":"This milestone retrieves branch-free polymorphism: different objects, one shared method contract, one caller.","hint_1":"Create one mixed `sensors = [...]` list.","hint_2":"Inside the loop, use `sensor.reading()`."},"starterCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\ntemperature = TemperatureSensor(temperature_zone, celsius)\nhumidity = HumiditySensor(humidity_zone, percent)\n\nprint(temperature.reading())\nprint(humidity.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"}},"checks":{"0":{"message":"Keep TemperatureSensor's specialized behavior working."},"1":{"message":"Keep HumiditySensor's specialized behavior working."},"2":{"message":"TemperatureSensor.reading() should still return the expected reading."},"3":{"message":"HumiditySensor.reading() should still return the expected reading."},"4":{"message":"Print both readings from one shared loop."}},"expectedOutput":"Temperature: North Bed = 21.5 C\nHumidity: Seedling Bench = 64%","sourceChecks":{"0":{"message":"Use one `for` loop over the mixed `sensors` collection."},"1":{"message":"Call the shared `reading()` method inside the loop without concrete-type branching."}}},"greenhouse_project_step_4_monitor_class_report":{"title":"Milestone 4: give GreenhouseMonitor collection ownership","prompt":"Continue from the exact Milestone 3 workspace. Complete `models/greenhouse_monitor.py`. `GreenhouseMonitor.__init__()` must create an empty `self.sensors` list; `add_sensor(self, sensor)` must append the object; and `print_report(self)` must use one loop over `self.sensors` and print each object's shared `reading()` result. Update `main.py` so it creates the monitor, adds the temperature and humidity sensors, and calls `monitor.print_report()`. Do not branch on sensor types. Keep the completed Sensor subclasses unchanged.","hint":"Retrieve the responsibility boundary from Module 8: the monitor owns the collection; each sensor still owns how its own reading is formatted.","help":{"concept":"The final class owns collection coordination while remaining polymorphic—it depends only on each object's `reading()` behavior.","hint_1":"Initialize `self.sensors = []`.","hint_2":"Append in `add_sensor()` and call `sensor.reading()` inside one report loop."},"starterCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n","starterFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nsensors = [\n TemperatureSensor(temperature_zone, celsius),\n HumiditySensor(humidity_zone, percent),\n]\n\nfor sensor in sensors:\n print(sensor.reading())\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"},"models_greenhouse_monitor_py":{"content":"# Added in Milestone 4.\n"}},"solutionCode":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\nfrom models.greenhouse_monitor import GreenhouseMonitor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nmonitor = GreenhouseMonitor()\nmonitor.add_sensor(TemperatureSensor(temperature_zone, celsius))\nmonitor.add_sensor(HumiditySensor(humidity_zone, percent))\nmonitor.print_report()\n","solutionFiles":{"main_py":{"content":"from models.temperature_sensor import TemperatureSensor\nfrom models.humidity_sensor import HumiditySensor\nfrom models.greenhouse_monitor import GreenhouseMonitor\n\ntemperature_zone = input()\ncelsius = float(input())\nhumidity_zone = input()\npercent = int(input())\n\nmonitor = GreenhouseMonitor()\nmonitor.add_sensor(TemperatureSensor(temperature_zone, celsius))\nmonitor.add_sensor(HumiditySensor(humidity_zone, percent))\nmonitor.print_report()\n"},"models___init___py":{"content":"# Package marker for greenhouse model imports.\n"},"models_sensor_py":{"content":"from abc import ABC, abstractmethod\n\n\nclass Sensor(ABC):\n def __init__(self, zone):\n self.zone = zone\n\n @abstractmethod\n def reading(self):\n pass\n"},"models_temperature_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass TemperatureSensor(Sensor):\n def __init__(self, zone, celsius):\n super().__init__(zone)\n self.celsius = celsius\n\n def reading(self):\n return f\"Temperature: {self.zone} = {self.celsius} C\"\n"},"models_humidity_sensor_py":{"content":"from models.sensor import Sensor\n\n\nclass HumiditySensor(Sensor):\n def __init__(self, zone, percent):\n super().__init__(zone)\n self.percent = percent\n\n def reading(self):\n return f\"Humidity: {self.zone} = {self.percent}%\"\n"},"models_greenhouse_monitor_py":{"content":"class GreenhouseMonitor:\n def __init__(self):\n self.sensors = []\n\n def add_sensor(self, sensor):\n self.sensors.append(sensor)\n\n def print_report(self):\n for sensor in self.sensors:\n print(sensor.reading())\n"}},"checks":{"0":{"message":"GreenhouseMonitor should be constructible without arguments."},"1":{"message":"Each monitor should own a `sensors` collection."},"2":{"message":"Keep the temperature subclass working after the monitor refactor."},"3":{"message":"Keep the humidity subclass working after the monitor refactor."}},"expectedOutput":"Temperature: North Bed = 21.5 C\nHumidity: Seedling Bench = 64%","sourceChecks":{"0":{"message":"Define `GreenhouseMonitor` in its model file."},"1":{"message":"Give each monitor its own empty `sensors` list."},"2":{"message":"`add_sensor()` should append the object it receives."},"3":{"message":"`print_report()` should use one shared `reading()` call without concrete-type branching."}}}}}},"overriding-and-specialization":{"label":"Overriding and Specialization","summary":"Override inherited behavior by keeping the same public method name while a subclass supplies a more specific implementation.","cards":{"sketch0":{"title":"Override inherited behavior"},"sketch1":{"title":"Override the method in one subclass"},"sketch2":{"title":"Specialize more than one subclass"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_overriding_and_specialization_sketch0":{"title":"Override label() on Book","prompt":"`Book` already inherits from `CatalogItem`, and `main.py` is complete. In `models/book.py`, override the inherited `label(self)` method so a `Book` returns `Book: ` followed by that object's title. Keep the method name `label`, keep `Book` inheriting from `CatalogItem`, and leave `models/catalog_item.py` and `main.py` unchanged.","hint":"Define `label(self)` inside `Book`. The child method should use `self.title` and return the specialized text.","help":{"concept":"An override uses the same method name as the inherited method but provides subclass-specific behavior.","hint_1":"Keep `class Book(CatalogItem)` unchanged.","hint_2":"Define `label(self)` directly inside `Book` and use `self.title`."},"starterCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","starterFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n # Override label() here.\n pass\n"}},"solutionCode":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\n\ntitle = input()\nbook = Book(title)\n\nprint(book.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"}},"checks":{"0":{"message":"Keep the parent `CatalogItem.label()` behavior unchanged."},"1":{"message":"`Book.label()` should specialize the visible title."},"2":{"message":"`Book.label()` should use the object's actual title, not a hard-coded example."},"3":{"message":"The override should work for other valid titles too."}},"expectedOutput":"Book: Project Hail Mary","sourceChecks":{"0":{"message":"Keep `Book` inheriting from `CatalogItem` so `label()` is a real override."},"1":{"message":"Define `label(self)` directly on `Book`."}}},"try_overriding_and_specialization_sketch1":{"title":"Override label() for Movie","prompt":"Use the same overriding pattern with another catalog type. In `models/movie.py`, override `label()` so `Movie(\"Inside Out\")` returns `Movie: Inside Out`. Then finish `main.py` by creating the movie and printing its label.","hint":"Book and Movie should both use `label()`, but each one can return a different kind of label.","help":{"concept":"Two subclasses can share a method name while producing different results. That sets up polymorphism in the next topic.","hint_1":"The method name should still be `label()`.","hint_2":"Return `Movie: ` followed by `self.title`."},"starterCode":"from models.movie import Movie\n\n# TODO: create Movie(\"Inside Out\").\n# TODO: print the movie label.\n","starterFiles":{"main_py":{"content":"from models.movie import Movie\n\n# TODO: create Movie(\"Inside Out\").\n# TODO: print the movie label.\n"},"models_catalog_item_py":{"content":"# Keep models/catalog_item.py unchanged for this step: Override label() for Movie.\nclass CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\n\nclass Movie(CatalogItem):\n # TODO: override label() so it returns \"Movie: <title>\".\n pass\n"}},"solutionCode":"from models.movie import Movie\n\nmovie = Movie(\"Inside Out\")\nprint(movie.label())\n","solutionFiles":{"main_py":{"content":"from models.movie import Movie\n\nmovie = Movie(\"Inside Out\")\nprint(movie.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"Movie.label() should return the movie-specific label."}},"expectedOutput":"Movie: Inside Out"},"try_overriding_and_specialization_sketch2":{"title":"Print both specialized labels","prompt":"Now use both specialized child classes. The `Book` and `Movie` classes are provided. In `main.py`, create `Book(\"Coraline\")` and `Movie(\"Coco\")`, then print each object's `label()` result on its own line.","hint":"Create one Book and one Movie. Call `.label()` on each object.","help":{"concept":"The call looks the same for both objects, but each subclass decides what its own label should look like.","hint_1":"Use `book.label()` for the first line.","hint_2":"Use `movie.label()` for the second line."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\n\n# TODO: create a Book for \"Coraline\".\n# TODO: create a Movie for \"Coco\".\n# TODO: print each object's label on its own line.\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\n# TODO: create a Book for \"Coraline\".\n# TODO: create a Movie for \"Coco\".\n# TODO: print each object's label on its own line.\n"},"models_catalog_item_py":{"content":"# Keep models/catalog_item.py unchanged for this step: Print both specialized labels.\nclass CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"# Keep models/book.py unchanged for this step: Print both specialized labels.\nfrom models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"# Keep models/movie.py unchanged for this step: Print both specialized labels.\nfrom models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\n\nbook = Book(\"Coraline\")\nmovie = Movie(\"Coco\")\nprint(book.label())\nprint(movie.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\nbook = Book(\"Coraline\")\nmovie = Movie(\"Coco\")\nprint(book.label())\nprint(movie.label())\n"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return self.title\n"},"models_book_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Book(CatalogItem):\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"from models.catalog_item import CatalogItem\n\nclass Movie(CatalogItem):\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"Book.label() should stay specialized."},"1":{"message":"Movie.label() should stay specialized."}},"expectedOutput":"Book: Coraline\nMovie: Coco"}},"practice":{"sc-overriding-purpose":{"title":"Why override an inherited method?","prompt":"`CatalogItem.label()` returns only the title. Why should `Book` override `label()` instead of inventing a different method name?","hint":"The caller should keep using the same public behavior.","help":{"concept":"Overriding preserves the inherited method contract while allowing the subclass to specialize its implementation.","hint_1":"The method name stays `label`.","hint_2":"The child can return a more specific result."},"options":{"a":"To stop `Book` from inheriting from `CatalogItem`","b":"To force callers to learn a new method name for every subclass","c":"To keep the `label()` contract while giving `Book` book-specific behavior","d":"To remove the title state inherited from `CatalogItem`"}},"fb-overriding-method-name":{"title":"Keep the inherited method name","prompt":"Complete the method name so `Book` overrides the method it inherits from `CatalogItem`.","hint":"An override uses the same method name as the parent.","help":{"concept":"Python recognizes the subclass implementation as an override because it uses the same method name.","hint_1":"The parent method is named `label`.","hint_2":"Do not rename it to `book_label`."},"template":"class Book(CatalogItem):\n def [blank1](self):\n return f\"Book: {self.title}\"","choices":["label","book_label","title","__init__"]},"dr-overriding-workflow":{"title":"Order the override steps","prompt":"Put the beginner workflow in order.","hint":"Begin with the base method, then specialize it in subclasses.","help":{"concept":"It is easiest to override after the base behavior already exists.","hint_1":"The shared method comes first.","hint_2":"Printing the result comes after the subclass method is ready."},"tokens":{"t1":"Write `label()` in CatalogItem","t2":"Create `Book.label()` with a book-specific return value","t3":"Create `Movie.label()` with a movie-specific return value","t4":"Make objects and print both labels"}},"sc-overriding-shared-contract":{"title":"Which label() runs?","prompt":"`CatalogItem.label()` returns `self.title`, while `Book.label()` returns `Book: ` plus the title. What does `Book(\"Coraline\").label()` return?","hint":"Python looks on the subclass before falling back to the parent.","help":{"concept":"When a subclass overrides a method, calls on that subclass use the subclass implementation.","hint_1":"`Book` defines its own `label()`.","hint_2":"The result includes the `Book: ` prefix."},"options":{"a":"Coraline","b":"Book: Coraline","c":"CatalogItem: Coraline","d":"Python raises an error because both classes define `label()`"}},"catalog-step-book-and-movie":{"title":"Specialize labels for two catalog subclasses","prompt":"You are extending a media catalog. The base `CatalogItem` already stores `title`. Complete both subclasses so they reuse the parent constructor and override `display_name()`: `BookItem` should return `\"<title> by <author>\"`, and `MovieItem` should return `\"<title> (<minutes> min)\"`. The workspace already includes a small `main.py` that prints both labels.","hint":"Both subclasses share the same method name, but each one formats the result differently.","help":{"concept":"Different subclasses can override the same base method in different ways while still fitting the same base-class contract.","hint_1":"Use `super().__init__(title)` in both subclass constructors before storing the extra field.","hint_2":"Write one `display_name()` method in each subclass, each returning its own specialized string format."},"starterCode":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())","starterFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n pass"},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n return f\"{self.title} by {self.author}\""},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n return f\"{self.title} ({self.minutes} min)\""}},"solutionCode":"from models.book_item import BookItem\nfrom models.movie_item import MovieItem\n\nbook = BookItem(\"Clean Code\", \"Robert C. Martin\")\nmovie = MovieItem(\"Arrival\", 116)\nprint(book.display_name())\nprint(movie.display_name())","checks":{"0":{"message":"Define a BookItem class."},"1":{"message":"Define a MovieItem class."},"2":{"message":"BookItem.display_name() should return the book label."},"3":{"message":"MovieItem.display_name() should return the movie label."}}},"catalog-step-mixed-report":{"title":"Build a report from mixed specialized items","prompt":"Build a mixed catalog report without checking object types manually. The workspace includes a base `CatalogItem` plus `BookItem` and `MovieItem` subclasses that all provide `display_name()`. Complete `build_display_report(items)` in `services/reporting.py` so it returns each item's display label in order. `main.py` will print the returned lines.","hint":"Loop through the mixed list and call the same `display_name()` method on every item.","help":{"concept":"Polymorphic services work by calling the same method on mixed related objects, while overriding lets each subclass provide its own specialized output.","hint_1":"Make sure each subclass overrides `display_name()` correctly before writing the service loop.","hint_2":"In the service function, iterate through `items` and append `item.display_name()` for each object in order."},"starterCode":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)","starterFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n return f\"{self.title} by {self.author}\""},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n return f\"{self.title} ({self.minutes} min)\""},"services_reporting_py":{"content":"def build_display_report(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)"},"models_catalog_item_py":{"content":"class CatalogItem:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return self.title"},"models_book_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass BookItem(CatalogItem):\n def __init__(self, title, author):\n super().__init__(title)\n self.author = author\n\n def display_name(self):\n return f\"{self.title} by {self.author}\""},"models_movie_item_py":{"content":"from models.catalog_item import CatalogItem\n\nclass MovieItem(CatalogItem):\n def __init__(self, title, minutes):\n super().__init__(title)\n self.minutes = minutes\n\n def display_name(self):\n return f\"{self.title} ({self.minutes} min)\""},"services_reporting_py":{"content":"def build_display_report(items):\n return [item.display_name() for item in items]"}},"solutionCode":"from models.catalog_item import CatalogItem\nfrom models.book_item import BookItem\nfrom models.movie_item import MovieItem\nfrom services.reporting import build_display_report\n\nitems = [\n CatalogItem(\"Notebook\"),\n BookItem(\"Refactoring\", \"Martin Fowler\"),\n MovieItem(\"Up\", 96),\n]\nfor line in build_display_report(items):\n print(line)"},"practice-specialized-display-label":{"title":"Override a display label in one subclass","prompt":"Define a base class `MediaItem` that stores `title` and has `display()` returning `Item: <title>`. Define `Song(MediaItem)` and override `display()` so it returns `Song: <title>`. Print the display text for one base item and one song.","hint":"Keep the shared version on the base class, then redefine only `display()` inside `Song`.","help":{"concept":"Overriding lets a subclass specialize one inherited behavior while keeping the rest of the shared base-class structure.","hint_1":"Keep the shared version on the base class, then redefine only `display()` inside `Song`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n # return Item: <title>\n pass\n\nclass Song(MediaItem):\n def display(self):\n # return Song: <title>\n pass\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n","starterFiles":{"main_py":{"content":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n # return Item: <title>\n pass\n\nclass Song(MediaItem):\n def display(self):\n # return Song: <title>\n pass\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n"}},"solutionCode":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n return f\"Item: {self.title}\"\n\nclass Song(MediaItem):\n def display(self):\n return f\"Song: {self.title}\"\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n","solutionFiles":{"main_py":{"content":"class MediaItem:\n def __init__(self, title):\n self.title = title\n\n def display(self):\n return f\"Item: {self.title}\"\n\nclass Song(MediaItem):\n def display(self):\n return f\"Song: {self.title}\"\n\nitem = MediaItem(\"Guide\")\nsong = Song(\"Sunrise\")\nprint(item.display())\nprint(song.display())\n"}}}}},"polymorphic-collections":{"label":"Polymorphic Collections","summary":"Use one shared method call across mixed objects so callers do not need type-specific branches.","cards":{"sketch0":{"title":"One loop, one shared method"},"sketch1":{"title":"Move the shared contract into a service"},"sketch2":{"title":"Move the loop into a helper"},"quiz":{"title":"Check your understanding"}},"tryIt":{"allowReveal":true,"try_polymorphic_collections_sketch0":{"title":"Use one loop for Book and Movie","prompt":"`catalog` already contains one `Book` and one `Movie`, and both classes already provide `label()`. In `main.py`, use one `for` loop over `catalog`. Inside that loop, call the current object's shared `label()` method and print the returned label. Do not branch on the concrete type with `isinstance()`, `type()`, `__class__`, or separate Book/Movie cases.","hint":"The loop should trust the shared method. Each item can answer `label()` without the caller first asking what class it is.","help":{"concept":"Polymorphism lets one caller use the same method on different object types. The object itself chooses the appropriate implementation.","hint_1":"Loop directly over `catalog`.","hint_2":"Inside the loop, use the current object's `label()` result."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\n# Use one for loop over catalog.\n# Call the shared label() method for each item and print the result.\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\n# Use one for loop over catalog.\n# Call the shared label() method for each item and print the result.\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\nfor item in catalog:\n print(item.label())\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\n\nbook_title = input()\nmovie_title = input()\n\ncatalog = [\n Book(book_title),\n Movie(movie_title),\n]\n\nfor item in catalog:\n print(item.label())\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"}},"checks":{"0":{"message":"Keep the Book object in the mixed list."},"1":{"message":"Keep the Movie object in the mixed list."},"2":{"message":"Print both labels from the loop."}},"expectedOutput":"Book: Coraline\nMovie: Arrival","sourceChecks":{"0":{"message":"Use one `for` loop over `catalog` so the same caller handles both object types."},"1":{"message":"Inside that loop, print the current object's `label()` result without branching on its concrete type."}}},"try_polymorphic_collections_sketch1":{"title":"Build a polymorphic catalog-report service","prompt":"`main.py`, `Book`, and `Movie` are already complete. In `services/catalog_report.py`, complete `build_labels(items)` so it returns one list containing each object's `label()` result in the same order as the input collection. Use one `for` loop over `items` and the shared `label()` method. The service must not branch on concrete types with `isinstance()`, `type()`, `__class__`, or separate Book/Movie cases.","hint":"The service should know only that each item has `label()`. It should not need to know which concrete class supplied that method.","help":{"concept":"A polymorphic service depends on shared behavior. New compatible classes can be added without adding another type-specific branch.","hint_1":"Iterate over `items` and collect each item's `label()` result.","hint_2":"Return the finished list after the loop."},"starterCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n","starterFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n\n # Use one for loop over items.\n # Add each object's label() result to labels.\n\n return labels\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\nfirst_kind = input().strip().lower()\nfirst_title = input()\nsecond_title = input()\n\nif first_kind == \"movie\":\n catalog = [Movie(first_title), Book(second_title)]\nelse:\n catalog = [Book(first_title), Movie(second_title)]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n\n for item in items:\n labels.append(item.label())\n\n return labels\n"}},"checks":{"0":{"message":"Return both labels so main.py can print two lines."},"1":{"message":"Keep the Movie object in the mixed list."},"2":{"message":"Print both labels from the loop."}},"expectedOutput":"Book: Dune\nMovie: Arrival","sourceChecks":{"0":{"message":"`build_labels(items)` should use one shared `label()` call inside a loop and return the collected labels without concrete-type branches."}}},"try_polymorphic_collections_sketch2":{"title":"Return labels from a helper","prompt":"Complete `build_labels(items)` in `services/catalog_report.py`. It must loop through the supplied items, collect each `item.label()` result in order, and return the list. `main.py` is already wired to print the returned labels.","hint":"Start with an empty list, append `item.label()` inside a loop, and return the finished list.","help":{"concept":"A reusable helper can depend on the shared `label()` behavior without knowing whether an item is a Book or Movie.","hint_1":"Start with an empty list, append `item.label()` inside a loop, and return the finished list.","hint_2":"Use the requested file boundary as part of the solution contract."},"starterCode":"# Run this provided script after completing the helper.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n","starterFiles":{"main_py":{"content":"# Run this provided script after completing the helper.\nfrom models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"# Keep the provided Book model unchanged.\nclass Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"# Keep the provided Movie model unchanged.\nclass Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n # TODO: return a list containing item.label() for every item.\n pass\n"}},"solutionCode":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n","solutionFiles":{"main_py":{"content":"from models.book import Book\nfrom models.movie import Movie\nfrom services.catalog_report import build_labels\n\ncatalog = [\n Book(\"A Wrinkle in Time\"),\n Movie(\"Up\"),\n]\n\nfor label in build_labels(catalog):\n print(label)\n"},"models_book_py":{"content":"class Book:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Book: {self.title}\"\n"},"models_movie_py":{"content":"class Movie:\n def __init__(self, title):\n self.title = title\n\n def label(self):\n return f\"Movie: {self.title}\"\n"},"services_catalog_report_py":{"content":"def build_labels(items):\n labels = []\n for item in items:\n labels.append(item.label())\n return labels\n"}},"checks":{"0":{"message":"Return both labels so main.py can print two lines."}},"expectedOutput":"Book: A Wrinkle in Time\nMovie: Up"}},"practice":{"sc-polymorphism-mixed-list":{"title":"Why use the shared method?","prompt":"A list contains `Book` and `Movie` objects, and both provide `label()`. What is the main polymorphic advantage?","hint":"Think about what the caller no longer needs to know.","help":{"concept":"Polymorphism lets the caller depend on shared behavior instead of branching on each concrete class.","hint_1":"The caller can make the same method call for every item.","hint_2":"The object decides which implementation runs."},"options":{"a":"Every object in the list must be the same concrete class","b":"One caller can use `label()` without checking whether an item is a Book or Movie","c":"Python automatically converts every object into the parent class","d":"The loop no longer needs to call any methods"}},"fb-polymorphism-shared-call":{"title":"Recognize polymorphic callers","prompt":"Which TWO designs rely on the shared `label()` behavior instead of concrete-type branching?","hint":"Choose callers that treat every compatible object through the same method.","help":{"concept":"A polymorphic caller asks for shared behavior. It does not need a separate Book path and Movie path.","hint_1":"A direct `item.label()` call is the shared contract.","hint_2":"Reject designs whose logic changes after checking the concrete class."},"template":"for item in catalog:\n print(item.[blank1]())","choices":["label","title","Book","super"],"options":{"a":"Loop through `catalog` and use each item's `label()` method","b":"Use `isinstance()` to choose a Book branch or Movie branch","c":"Pass the mixed collection to a helper that calls `label()` on each item","d":"Check `type(item)` and manually build a different label for every class"}},"dr-polymorphism-loop-order":{"title":"Order the loop steps","prompt":"Put these steps in order for a polymorphic helper.","hint":"Start with the list, then loop, then call the shared method.","help":{"concept":"A polymorphic helper follows a simple receive-loop-call-store pattern.","hint_1":"The list comes before the loop.","hint_2":"The append step happens after the method returns a value."},"tokens":{"t1":"Receive the mixed items list","t2":"Loop through each item","t3":"Call `item.label()`","t4":"Add the returned label to the results list"}},"sc-polymorphism-no-type-check":{"title":"Complete the shared call","prompt":"Complete the method name so the same loop works for every compatible object in `catalog`.","hint":"Use the method contract shared by Book and Movie.","help":{"concept":"The shared method name is what allows one loop to remain unaware of the concrete object type.","hint_1":"Both classes provide the same labeling behavior.","hint_2":"The loop should call `item.label()`."},"options":{"a":"Write a separate loop for every subclass forever","b":"Rename the method in each subclass so they are all different","c":"Check each object type before every method call","d":"Call the same method on each object in the mixed list"},"template":"for item in catalog:\n print(item.[blank1]())","choices":["label","book_label","movie_label","__class__"]},"project-polymorphic-collections-step4":{"title":"Add a new subclass without changing the service","prompt":"Add a `Magazine` object to a mixed collection that already contains book and video objects. Complete `Magazine.display_name()` so the same loop can call `display_name()` on every item and print three labels. The magazine label should be `Magazine: Science Weekly`.","hint":"Give `Magazine` the same method name used by the other objects in the collection.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())","starterFiles":{"main_py":{"content":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())"},"models_magazine_py":{"content":"class Magazine:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())"},"models_magazine_py":{"content":"class Magazine:\n def __init__(self, title):\n self.title = title\n\n def display_name(self):\n return f\"Magazine: {self.title}\""}},"solutionCode":"from models.magazine import Magazine\n\nclass Book:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Book: {self.title}\"\n\nclass Video:\n def __init__(self, title):\n self.title = title\n def display_name(self):\n return f\"Video: {self.title}\"\n\nitems = [Book(\"Refactoring\"), Video(\"Git Basics\"), Magazine(\"Science Weekly\")]\nfor item in items:\n print(item.display_name())"},"project-polymorphic-collections-step5":{"title":"Build a checkout summary from mixed rentals","prompt":"A rental desk stores book and movie rentals in the same list. Complete `checkout_line()` in both classes so one loop can print a line for each object without checking its type. Use the formats `Book rental: <title> (<days> days)` and `Movie rental: <title> (<days> days)`.","hint":"Both classes need the same method name, but each can format its own label.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())","starterFiles":{"main_py":{"content":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())"},"models_book_rental_py":{"content":"class BookRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n pass"},"models_movie_rental_py":{"content":"class MovieRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())"},"models_book_rental_py":{"content":"class BookRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n return f\"Book rental: {self.title} ({self.days} days)\""},"models_movie_rental_py":{"content":"class MovieRental:\n def __init__(self, title, days):\n self.title = title\n self.days = days\n\n def checkout_line(self):\n return f\"Movie rental: {self.title} ({self.days} days)\""}},"solutionCode":"from models.book_rental import BookRental\nfrom models.movie_rental import MovieRental\n\nrentals = [BookRental(\"Refactoring\", 7), MovieRental(\"Design Talk\", 3)]\nfor rental in rentals:\n print(rental.checkout_line())"},"project-polymorphic-collections-step6":{"title":"Create a stock alert service for mixed inventory items","prompt":"A store keeps book and supply objects in one inventory list. Complete each class's `alert_line()` method and `low_stock_lines(items)` so the service returns alerts only for objects whose `quantity` is below 3. The service should call the shared `alert_line()` method instead of checking item types.","hint":"Filter by the shared `quantity` attribute, then call `alert_line()` on each matching object.","help":{"concept":"This support text was repaired because the original wording revealed the answer too directly.","hint_1":"Compare the question to the lesson example and remove details that do not match the requested concept.","hint_2":"Use the role or evidence named in the prompt instead of relying on answer wording."},"starterCode":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)","starterFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)"},"models_book_item_py":{"content":"class BookItem:\n def __init__(self, title, quantity):\n self.title = title\n self.quantity = quantity\n\n def alert_line(self):\n pass"},"models_supply_item_py":{"content":"class SupplyItem:\n def __init__(self, name, quantity):\n self.name = name\n self.quantity = quantity\n\n def alert_line(self):\n pass"},"services_alert_service_py":{"content":"def low_stock_lines(items):\n pass"}},"solutionFiles":{"main_py":{"content":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)"},"models_book_item_py":{"content":"class BookItem:\n def __init__(self, title, quantity):\n self.title = title\n self.quantity = quantity\n\n def alert_line(self):\n return f\"LOW STOCK: Book {self.title} has {self.quantity} left\""},"models_supply_item_py":{"content":"class SupplyItem:\n def __init__(self, name, quantity):\n self.name = name\n self.quantity = quantity\n\n def alert_line(self):\n return f\"LOW STOCK: Supply {self.name} has {self.quantity} left\""},"services_alert_service_py":{"content":"def low_stock_lines(items):\n return [item.alert_line() for item in items if item.quantity < 3]"}},"solutionCode":"from models.book_item import BookItem\nfrom models.supply_item import SupplyItem\nfrom services.alert_service import low_stock_lines\n\nitems = [\n BookItem(\"API Design\", 2),\n SupplyItem(\"Sticky Notes\", 1),\n BookItem(\"Python Guide\", 5),\n]\nfor line in low_stock_lines(items):\n print(line)"}}}}},"python-data-functions":{"python-5-lists-tuples-and-dictionaries":{"creating-and-indexing-lists":{"label":"Creating and Indexing Lists","summary":"Create ordered lists and read items with positive and negative indexes.","cards":{"course-introduction":{"title":"Course introduction"},"sketch0":{"title":"Creating lists"},"sketch1":{"title":"Reading items by index"},"sketch2":{"title":"Reading from the end"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-first-index":{"title":"First item index","prompt":"Which index gets the first item from a Python list?","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"0","b":"1","c":"-1","d":"first"}},"sc-whole-list":{"title":"Create a list","prompt":"Which line correctly creates a Python list containing the numbers 3, 5, and 7 in that order?","hint":"Python list literals use square brackets and commas.","help":{"concept":"A list literal uses square brackets around comma-separated items.","hint_1":"Look at the outer punctuation around the three values.","hint_2":"Choose the option written as `[3, 5, 7]`."},"options":{"a":"numbers = [3, 5, 7]","b":"numbers = (3, 5, 7)","c":"numbers = {3, 5, 7}","d":"numbers = \"3, 5, 7\""}},"mc-valid-index-expressions":{"title":"Valid list access","prompt":"Choose all expressions that correctly access an item from `letters = [\"a\", \"b\", \"c\"]`.","hint":"A valid access uses the list name followed by an index in square brackets.","help":{"concept":"To access a list item, Python uses the syntax `list_name[index]` with a numeric index.","hint_1":"Check which choices use square brackets after `letters`.","hint_2":"Two choices use the correct indexing pattern and refer to real positions in this three-item list."},"options":{"a":"letters[0]","b":"letters[2]","c":"letters(1)"}},"mc-true-about-lists":{"title":"Facts about lists","prompt":"Choose all true statements about Python lists.","hint":"Compare the options with the exact syntax and result required by the prompt.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"Lists keep items in order.","b":"The first item in a list has index 0.","c":"Lists must contain only numbers.","d":"Square brackets are used to create lists."}},"dr-build-list-line":{"title":"Build the list line","prompt":"Put the tokens in order to create a line of code that stores `\"pen\"`, `\"pencil\"`, and `\"eraser\"` in a list named `items`.","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"tokens":{"t1":"items","t2":"=","t3":"[","t4":"\"pen\"","t5":",","t6":"\"pencil\"","t7":"\"eraser\"","t8":"]"}},"dr-index-output-order":{"title":"Trace indexed output","prompt":"A program runs this code:\n\n`colors = [\"red\", \"blue\", \"green\"]`\n`print(colors[2])`\n`print(colors[0])`\n`print(colors[1])`\n\nArrange the printed lines in the order they appear.","hint":"Resolve each index before ordering the three printed values.","help":{"concept":"Index 0 is the first item, index 1 is the second, and index 2 is the third.","hint_1":"Work through the three `print()` calls from top to bottom.","hint_2":"The calls read indexes 2, 0, then 1."},"tokens":{"t1":"green","t2":"red","t3":"blue"}},"fb-second-item":{"title":"Read the second item","prompt":"Complete the code so it prints the second item in `letters`.","hint":"Python starts list indexes at 0.","help":{"concept":"The first three list positions use indexes 0, 1, and 2.","hint_1":"If the first item is index 0, move forward one index to reach the second item.","hint_2":"Use index `1`."},"template":"letters = [\"a\", \"b\", \"c\"]\nprint(letters[[blank1]])","choices":["0","1","2","3"]},"fb-list-name":{"title":"Complete the list assignment","prompt":"Choose the missing variable name so the list is stored in `numbers`.","hint":"Only the name before `=` is missing.","help":{"concept":"In an assignment, the variable name goes on the left side of `=` and receives the list value on the right.","hint_1":"The blank should be the variable that will hold `[4, 8, 12]`.","hint_2":"Pick the choice that is a sensible variable name, not a keyword or function."},"template":"[blank1] = [4, 8, 12]","choices":["numbers","print","index","list()"]},"ci-print-first-last":{"title":"Print the first and last list items","prompt":"Three fruit labels come in one at a time. Store the inputs in a list, then print the first fruit and the last fruit on separate lines.\n\nFor example, if the inputs are `apple`, `banana`, and `cherry`, your program should print:\n`apple`\n`cherry`.","hint":"Read the task \"Print the first and last list items\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"word1 = input()\nword2 = input()\nword3 = input()\n\n# Store the words in a list.\n# Then print the first item and the last item on separate lines.","solutionCode":"word1 = input()\nword2 = input()\nword3 = input()\n\nwords = [word1, word2, word3]\nprint(words[0])\nprint(words[2])","sourceChecks":{"0":{"message":"Use index 0 to read the first item instead of printing the input directly."},"1":{"message":"Use an index to read the last item from the list."}}},"ci-print-second-number":{"title":"Print the second number","prompt":"A scoreboard sends three numbers in order. Put them into a list, then print the second item from that list.\n\nFor example, if the inputs are `4`, `9`, and `2`, your program should print:\n`9`.","hint":"The second item in a list is at index 1.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\n\n# Put the numbers into a list.\n# Print the second item.","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\n\nnumbers = [a, b, c]\nprint(numbers[1])","sourceChecks":{"0":{"message":"Use index 1 to read the second item from the list."}}},"ci-build-and-show-list":{"title":"Build a list from input","prompt":"A paint shelf needs a quick inventory. Collect the three input colors into one list and print the finished list.\n\nFor example, if the inputs are `red`, `blue`, and `green`, your program should print:\n`['red', 'blue', 'green']`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"color1 = input()\ncolor2 = input()\ncolor3 = input()\n\n# Create a list with the three colors.\n# Print the whole list.","solutionCode":"color1 = input()\ncolor2 = input()\ncolor3 = input()\n\ncolors = [color1, color2, color3]\nprint(colors)","sourceChecks":{"0":{"message":"Create a list with color1, color2, and color3 before printing it."}}},"try-creating-and-indexing-lists-checkpoint":{"title":"Index and print list values","prompt":"Create the list `[\"Ava\", \"Mia\", \"Zoe\"]`. Print the first name, then print the last name.","hint":"Use index `0` for the first item and `-1` for the last item.","help":{"concept":"List indexing lets you retrieve a value by position.","hint_1":"Use index `0` for the first item and `-1` for the last item.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"names = []\n\n# Create the list [\"Ava\", \"Mia\", \"Zoe\"].\n# Print the first name, then print the last name.\n","solutionCode":"names = [\"Ava\", \"Mia\", \"Zoe\"]\nprint(names[0])\nprint(names[-1])\n","sourceChecks":{"0":{"message":"Create the names list instead of only printing the final answers."},"1":{"message":"Use names[0] to print the first name instead of typing Ava directly."},"2":{"message":"Use an index on names to print the last name instead of typing Zoe directly."}}},"try-creating-and-indexing-lists-sketch0":{"title":"Build a list from input","prompt":"Three club names arrive as input. Store them, in the same order, in a list named `clubs`, then print the list. Do not hard-code the club names.","hint":"Build `clubs` from the three input variables in their original order, then print `clubs`.","help":{"concept":"A list can collect values that are already stored in variables.","hint_1":"Assign the three input variables to a list named `clubs` in their original order.","hint_2":"After creating `clubs`, print the variable itself with `print(clubs)`."},"starterCode":"club1 = input()\nclub2 = input()\nclub3 = input()\n\n# Create a list named clubs containing the three inputs.\n# Print the whole list.\n","solutionCode":"club1 = input()\nclub2 = input()\nclub3 = input()\n\nclubs = [club1, club2, club3]\nprint(clubs)\n","sourceChecks":{"0":{"message":"Create a variable named `clubs` as required by the prompt."},"1":{"message":"Print `clubs` itself after creating it."}}},"try-creating-and-indexing-lists-sketch1":{"title":"Read two different positions","prompt":"The list `stations` is already provided. Use list indexing to print the third station first and the first station second, each on its own line. Do not hard-code the station names.","hint":"Use the list positions directly: the third item is `stations[2]` and the first is `stations[0]`.","help":{"concept":"This exercise practices reading values from a list by index rather than typing the known values directly.","hint_1":"Print the third item with `stations[2]`.","hint_2":"Then print the first item with `stations[0]`."},"starterCode":"stations = [\"Oak\", \"Pine\", \"Lake\", \"Hill\"]\n\n# Print the third station.\n# Then print the first station.\n","solutionCode":"stations = [\"Oak\", \"Pine\", \"Lake\", \"Hill\"]\nprint(stations[2])\nprint(stations[0])\n","sourceChecks":{"0":{"message":"Use `stations[2]` to read the third station instead of hard-coding `Lake`."},"1":{"message":"Use `stations[0]` to read the first station instead of hard-coding `Oak`."}}},"try-creating-and-indexing-lists-sketch2":{"title":"Use the last item after building a list","prompt":"Four delivery stops arrive as input. Store them, in their original order, in a list named `stops`. Then print only the final stop by using negative indexing on that list. Do not print the fourth input variable directly.","hint":"Create `stops = [stop1, stop2, stop3, stop4]`, then use `stops[-1]`.","help":{"concept":"Negative indexing reads relative to the end of a list; `-1` means the final item.","hint_1":"Build the `stops` list from all four input variables in their original order.","hint_2":"Print the final item from the list with `print(stops[-1])`, not `print(stop4)`."},"starterCode":"stop1 = input()\nstop2 = input()\nstop3 = input()\nstop4 = input()\n\n# Create a list named stops containing the four inputs.\n# Print the final stop using negative indexing.\n","solutionCode":"stop1 = input()\nstop2 = input()\nstop3 = input()\nstop4 = input()\n\nstops = [stop1, stop2, stop3, stop4]\nprint(stops[-1])\n","sourceChecks":{"0":{"message":"Create `stops = [stop1, stop2, stop3, stop4]` as the prompt requires."},"1":{"message":"Use `stops[-1]` to read the final stop instead of printing `stop4` directly."}}},"sc-last-negative-index":{"title":"Read the last item","prompt":"Which expression gets the last item from `tasks` without needing to know how many items are in the list?","hint":"Python can count backward from the end of a list with negative indexes.","help":{"concept":"Index `-1` always refers to the final item in a non-empty list.","hint_1":"Positive indexes count from the beginning; negative indexes count from the end.","hint_2":"Use `tasks[-1]`."},"options":{"a":"tasks[-1]","b":"tasks[0]","c":"tasks[1]","d":"tasks[\"last\"]"}}},"tryIt":{"try_creating_and_indexing_lists_checkpoint":{"title":"Try it yourself","prompt":"Create the list `[\"Ava\", \"Mia\", \"Zoe\"]`. Print the first name, then print the last name."},"try_creating_and_indexing_lists_sketch0":{"title":"Try it yourself","prompt":"Three club names arrive as input. Store them, in the same order, in a list named `clubs`, then print the list. Do not hard-code the club names."},"try_creating_and_indexing_lists_sketch1":{"title":"Try it yourself","prompt":"The list `stations` is already provided. Use list indexing to print the third station first and the first station second, each on its own line. Do not hard-code the station names."},"try_creating_and_indexing_lists_sketch2":{"title":"Try it yourself","prompt":"Four delivery stops arrive as input. Store them, in their original order, in a list named `stops`. Then print only the final stop by using negative indexing on that list. Do not print the fourth input variable directly."},"allowReveal":true}},"dictionary-basics":{"label":"Dictionary Basics","summary":"Create dictionaries with labeled key-value pairs, retrieve values by key, and check whether a key exists before reading it.","cards":{"sketch0":{"title":"Creating labeled dictionary records"},"sketch1":{"title":"Reading values by key"},"sketch2":{"title":"Checking whether a key exists"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-dict-best-choice":{"title":"Choose labeled data","prompt":"You need to store a person's name, age, and city so each value has a clear label. Which collection is the best fit?","hint":"Choose the collection designed around key-value pairs.","help":{"concept":"A dictionary connects each value to a key such as `\"name\"`, `\"age\"`, or `\"city\"`.","hint_1":"A list or tuple relies mainly on positions.","hint_2":"Choose the collection that lets you look up a value by a label."},"options":{"a":"A dictionary","b":"A tuple","c":"A single string","d":"A number"}},"sc-dict-lookup":{"title":"Read a value by key","prompt":"Given `pet = {\"type\": \"cat\", \"age\": 3}`, which expression gets the value `\"cat\"`?","hint":"Use the dictionary name followed by the exact key in square brackets.","help":{"concept":"Dictionary lookup uses `dictionary[key]`.","hint_1":"The value `\"cat\"` is stored under the key `\"type\"`.","hint_2":"Use `pet[\"type\"]`."},"options":{"a":"pet[0]","b":"pet(\"type\")","c":"pet[\"type\"]","d":"type[\"pet\"]"}},"mc-dict-parts":{"title":"Identify dictionary parts","prompt":"Which statements about this dictionary are correct?\n\n`item = {\"name\": \"pen\", \"price\": 2}`\n\nChoose all correct answers.","hint":"Separate keys from values in each pair.","help":{"concept":"In a dictionary, each entry has a key on the left of the colon and a value on the right.","hint_1":"Check the pair `\"name\": \"pen\"` and the pair `\"price\": 2`.","hint_2":"The strings before colons are keys; the data after colons are values."},"options":{"a":"`\"name\"` is a key","b":"`\"pen\"` is a value","c":"`2` is a value","d":"`\"price\"` is a value"}},"mc-dict-operations":{"title":"Valid dictionary actions","prompt":"Which lines correctly work with a dictionary named `scores = {\"Ava\": 10, \"Ben\": 8}`? Choose all correct answers.","hint":"Think about looking up by key and assigning by key.","help":{"concept":"You can read a dictionary value with `dict[key]` and update or add entries with `dict[key] = value`.","hint_1":"One correct pattern reads a value using a name key in square brackets.","hint_2":"Another correct pattern changes or adds a value by putting a key in square brackets on the left side of `=`."},"options":{"a":"`scores[\"Ava\"]`","b":"`scores[1]`","c":"`scores[\"Ben\"] = 9`","d":"`scores.add(\"Kai\", 7)`"}},"dr-dict-create-order":{"title":"Build a dictionary step by step","prompt":"Put these code pieces in the correct order to create a dictionary and print one value.","hint":"Create the dictionary first, then read from it.","help":{"concept":"Python must create and assign the dictionary before you can look up a value from it.","hint_1":"Start with the variable name and assignment to a dictionary literal.","hint_2":"The print line should come after the dictionary exists, and the lookup uses the key `\"name\"`."},"tokens":{"t1":"person = {","t2":"\"name\": \"Ava\"","t3":"}","t4":"print(person[\"name\"])"}},"dr-dict-update-order":{"title":"Order an update example","prompt":"Arrange these lines to create a dictionary, update a value, and print the updated result.","hint":"The dictionary must exist before the update line.","help":{"concept":"Updating a dictionary uses assignment with a key after the dictionary has already been created.","hint_1":"First create `stock`, then change the value for `\"apples\"`, then print it.","hint_2":"The print line belongs last because it should show the updated value, not the original one."},"tokens":{"t1":"stock = {\"apples\": 5}","t2":"stock[\"apples\"] = 7","t3":"print(stock[\"apples\"])"}},"fb-dict-literal":{"title":"Complete a dictionary literal","prompt":"Choose the missing value to finish the dictionary entry.","hint":"The blank should be the value paired with the key `\"color\"`.","help":{"concept":"A dictionary entry has the form `key: value`, so the missing part here is the value for one key.","hint_1":"The key is already written as `\"color\"`.","hint_2":"Pick the choice that can act as the string value stored for that key."},"template":"paint = {\"color\": [blank1]}","choices":["\"blue\"","color","Lesson notes panel","Color theme picker"]},"fb-dict-key-lookup":{"title":"Complete a key lookup","prompt":"Choose the missing key so the expression gets the age value.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"person = {\"name\": \"Ivy\", \"age\": 12}\nprint(person[[blank1]])","choices":["\"age\"","12","\"Ivy\"","0"]},"ci-make-dictionary":{"title":"Return a simple dictionary","prompt":"Write `make_book(title, pages)` so it returns one dictionary describing the book. The dictionary should use the keys `\"title\"` and `\"pages\"`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_book(title, pages):\n # return a dictionary with keys \"title\" and \"pages\"\n pass","solutionCode":"def make_book(title, pages):\n return {\"title\": title, \"pages\": pages}"},"ci-get-score":{"title":"Look up a value in a dictionary","prompt":"Write `get_score(scores, name)` so it looks up `name` in the `scores` dictionary and returns that score.","hint":"Read the task \"Look up a value in a dictionary\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def get_score(scores, name):\n # return the score for the given name\n pass","solutionCode":"def get_score(scores, name):\n return scores[name]"},"ci-update-dictionary":{"title":"Add or update a dictionary entry","prompt":"Write `set_price(prices, item, amount)` so it updates the `prices` dictionary with the given item and amount, then returns the updated dictionary.","hint":"Read the task \"Add or update a dictionary entry\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def set_price(prices, item, amount):\n # update the dictionary and return it\n pass","solutionCode":"def set_price(prices, item, amount):\n prices[item] = amount\n return prices"},"try-dictionary-basics-checkpoint":{"title":"Create and read a dictionary","prompt":"Create a dictionary for `name` and `score`, then print the score.","hint":"Use the key `\"score\"` to read the value.","help":{"concept":"A dictionary stores values under named keys.","hint_1":"Use the key `\"score\"` to read the value.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"student = {}\n\n# Store name Ava and score 92.\n# Then print the score.\n","solutionCode":"student = {\"name\": \"Ava\", \"score\": 92}\nprint(student[\"score\"])\n","sourceChecks":{"0":{"message":"Create a dictionary variable named student."},"1":{"message":"Use the score key to read the score from student."}}},"try-dictionary-basics-sketch0":{"title":"Build a profile dictionary","prompt":"A name and age arrive as input. Create a dictionary named `profile` with the keys `\"name\"` and `\"age\"`, storing the input values under the matching keys. Then print the whole dictionary. Use a dictionary literal assigned to `profile`; the grader checks that `profile` contains the explicitly requested `\"name\"` and `\"age\"` keys.","hint":"Use a dictionary literal with two `key: value` pairs.","help":{"concept":"A dictionary literal uses `{}` and separates each key from its value with a colon.","hint_1":"Store the variable `name` under the key `\"name\"` and `age` under the key `\"age\"`.","hint_2":"Create `profile = {\"name\": name, \"age\": age}`, then print `profile`."},"starterCode":"name = input()\nage = int(input())\n\n# Create profile with the keys \"name\" and \"age\".\n# Store the input values under those keys.\n# Print the whole dictionary.\n","solutionCode":"name = input()\nage = int(input())\n\nprofile = {\"name\": name, \"age\": age}\nprint(profile)\n","sourceChecks":{"0":{"message":"Create the requested dictionary in a variable named `profile`."},"1":{"message":"Include the explicitly requested `\"name\"` key in the dictionary."},"2":{"message":"Include the explicitly requested `\"age\"` key in the dictionary."}}},"try-dictionary-basics-sketch1":{"title":"Look up a price from input","prompt":"The dictionary `prices` is already defined. Read an item name from input and print the price stored under that key. The test inputs will always be keys that exist in `prices`.","hint":"Use the input variable as the key inside square brackets.","help":{"concept":"A dictionary lookup can use a variable key, not only a literal string.","hint_1":"The selected key is stored in `item`.","hint_2":"Print `prices[item]`."},"starterCode":"prices = {\"notebook\": 4, \"marker\": 2, \"folder\": 3}\nitem = input()\n\n# Print the value stored under the key in item.\n","solutionCode":"prices = {\"notebook\": 4, \"marker\": 2, \"folder\": 3}\nitem = input()\n\nprint(prices[item])\n","sourceChecks":{"0":{"message":"Update profile['age'] to 12 instead of replacing the final dictionary."}}},"try-dictionary-basics-sketch2":{"title":"Check whether a setting exists","prompt":"The dictionary `settings` contains several configuration keys. Read a key from input. If that key exists in `settings`, print `found`; otherwise print `missing`.","hint":"Use `key in settings` as the condition.","help":{"concept":"The `in` operator checks whether a dictionary contains a key without trying to read its value.","hint_1":"Use `if key in settings:` for the found case.","hint_2":"Print `found` in the `if` block and `missing` in the `else` block."},"starterCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\n# Print \"found\" if key exists in settings.\n# Otherwise print \"missing\".\n","solutionCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\nif key in settings:\n print(\"found\")\nelse:\n print(\"missing\")\n","sourceChecks":{"0":{"message":"Create a dictionary variable named scores."},"1":{"message":"Use Ava as a key in scores."},"2":{"message":"Use Mia as a key in scores."}}},"sc-key-value-role":{"title":"Identify a key and its value","prompt":"In `book = {\"title\": \"Kindred\", \"pages\": 264}`, what is `\"pages\"`?","hint":"Look at which side of the colon the item appears on.","help":{"concept":"In a dictionary entry, the key appears before the colon and its value appears after the colon.","hint_1":"The pair here is `\"pages\": 264`.","hint_2":"`\"pages\"` is the key; `264` is the value."},"options":{"a":"A key","b":"A value","c":"A list index","d":"A method"}},"sc-key-membership":{"title":"Check for a key safely","prompt":"Given `profile = {\"name\": \"Ava\", \"age\": 12}`, which expression checks whether the key `\"city\"` exists in the dictionary?","hint":"Use the membership operator with the key on the left and the dictionary on the right.","help":{"concept":"For dictionaries, `key in dictionary` checks whether that key exists.","hint_1":"You are checking for a key, not reading its value yet.","hint_2":"Use `\"city\" in profile`."},"options":{"a":"\"city\" in profile","b":"profile[\"city\"]","c":"\"city\" == profile","d":"profile.in(\"city\")"}}},"tryIt":{"try_dictionary_basics_checkpoint":{"title":"Try it yourself","prompt":"Create a dictionary for `name` and `score`, then print the score."},"try_dictionary_basics_sketch0":{"title":"Try it yourself","prompt":"A name and age arrive as input. Create a dictionary named `profile` with the keys `\"name\"` and `\"age\"`, storing the input values under the matching keys. Then print the whole dictionary. Use a dictionary literal assigned to `profile`; the grader checks that `profile` contains the explicitly requested `\"name\"` and `\"age\"` keys."},"try_dictionary_basics_sketch1":{"title":"Try it yourself","prompt":"Read a valid item key from input and print the matching value from `prices`."},"try_dictionary_basics_sketch2":{"title":"Try it yourself","prompt":"Read a key from input and print whether that key exists in `settings`."},"allowReveal":true}},"list-methods-and-mutation":{"label":"List Methods and Mutation","summary":"Change existing list items, add and remove values, capture removed items with pop(), and sort a list in place.","cards":{"sketch0":{"title":"Replacing an item by index"},"sketch1":{"title":"Adding an item with append()"},"sketch2":{"title":"Removing a matching value"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Removing by position with pop()"},"sketch4":{"title":"Sorting the same list"}},"quiz":{"sc-1":{"title":"Which method adds to the end?","prompt":"Which list method adds one new item to the end of a list?","hint":"Use execution order as evidence instead of choosing by familiar wording.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"append()","b":"remove()","c":"pop()","d":"sort()"}},"sc-2":{"title":"What does pop return?","prompt":"In Python, what does `items.pop(1)` return?","hint":"`pop()` both changes the list and gives you something back.","help":{"concept":"`pop(index)` removes the item at the given index and returns that removed item.","hint_1":"Index `1` means the second item in the list.","hint_2":"The return value is not the shortened list itself; it is the element that was taken out."},"options":{"a":"The item that was removed at index 1","b":"A copy of the whole list","c":"The length of the list after removal","d":"Nothing at all"}},"mc-1":{"title":"Methods that mutate a list","prompt":"Which of these operations change the original list? Choose all that apply.","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"append(5)","b":"remove(5)","c":"sort()","d":"len(my_list)"}},"mc-2":{"title":"Valid list method uses","prompt":"Which lines are valid ways to use common list methods on `numbers = [3, 1, 2]`? Choose all that apply.","hint":"Check whether each method name matches the kind of argument it expects.","help":{"concept":"Different list methods expect different inputs: `append` takes a value, `remove` takes a value, and `pop` usually takes an index.","hint_1":"Ask whether the method is removing by value or by position.","hint_2":"One choice mixes up `remove` with index behavior, and one choice uses `sort` with an argument it does not need here."},"options":{"a":"numbers.append(4)","b":"numbers.remove(1)","c":"numbers.pop(0)","d":"numbers.sort(2)"}},"dr-1":{"title":"Append then inspect","prompt":"Put these steps in the correct order to add `7` to a list and display the updated list.","hint":"First create the list, then change it, then print it.","help":{"concept":"A short list program usually follows a sequence: create data, mutate data, then inspect the result with `print()`.","hint_1":"You cannot append to a list before the list exists.","hint_2":"Printing should happen after the append if you want to see the changed list."},"tokens":{"t1":"numbers = [1, 2]","t2":"numbers.append(7)","t3":"print(numbers)"}},"dr-2":{"title":"Remove, pop, then print","prompt":"Arrange the lines to produce a program that removes `\"b\"`, then pops the last remaining item into `taken`, then prints `taken`.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"letters = [\"a\", \"b\", \"c\"]","t2":"letters.remove(\"b\")","t3":"taken = letters.pop()","t4":"print(taken)"}},"fb-1":{"title":"Complete an append call","prompt":"Choose the value that makes `numbers.append(...)` add `10` to the list.","hint":"`append()` needs the item you want to add inside the parentheses.","help":{"concept":"To add one item to the end of a list, place that item as the argument to `append()`.","hint_1":"The blank is the new value being added, not the list name or method name.","hint_2":"Pick the choice that would make the list gain the number ten."},"template":"numbers = [1, 2]\nnumbers.append([blank1])","choices":["numbers","append","10","pop"]},"fb-2":{"title":"Complete a sort statement","prompt":"Choose the method name that sorts `scores` in place.","hint":"This method puts list items in order and changes the list itself.","help":{"concept":"Choose the list method that rearranges the existing list into order instead of returning a separate sorted copy.","hint_1":"The blank should be a method that works directly on a list variable.","hint_2":"It is not a method for adding or removing items."},"template":"scores = [4, 1, 3]\nscores.[blank1]()","choices":["append","remove","sort","pop"]},"ci-1":{"title":"Add an item and print the list","prompt":"A pencil case already has `pen` and `pencil`. Read one more item from input, add it to `items`, and print the updated list.\n\nFor example, if the input is `eraser`, your program should print:\n`['pen', 'pencil', 'eraser']`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"item = input()\nitems = [\"pen\", \"pencil\"]\n\n# Add the input item to the list.\n# Then print the updated list.","solutionCode":"item = input()\nitems = [\"pen\", \"pencil\"]\nitems.append(item)\nprint(items)","sourceChecks":{"0":{"message":"Use items.append(item) so the list is really mutated."}}},"ci-2":{"title":"Remove a value and show the result","prompt":"The list `colors` starts as `['red', 'blue', 'green']`. Read one color from input, remove that value from the list, and print the updated list.\n\nFor example, if the input is `blue`, your program should print:\n`['red', 'green']`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"color = input()\ncolors = ['red', 'blue', 'green']\n\n# Remove the input color from the list.\n# Then print the updated list.","solutionCode":"color = input()\ncolors = ['red', 'blue', 'green']\ncolors.remove(color)\nprint(colors)","sourceChecks":{"0":{"message":"Use colors.remove(color) so the list is really mutated."}}},"ci-3":{"title":"Sort numbers from input","prompt":"Three quiz scores arrive out of order. Put the input numbers into `numbers`, sort the list from smallest to largest, and print the sorted list.\n\nFor example, if the inputs are `9`, `2`, and `5`, your program should print:\n`[2, 5, 9]`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\n\nnumbers = [a, b, c]\n\n# Sort the list.\n# Then print the sorted list.","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\n\nnumbers = [a, b, c]\nnumbers.sort()\nprint(numbers)","sourceChecks":{"0":{"message":"Use numbers.sort() so the list is really sorted in place."}}},"try-list-methods-and-mutation-checkpoint":{"title":"Append 10 to a list","prompt":"Start with `numbers = [3, 1, 2]`. Add `10` to the end of the list, then print the updated list.","hint":"Use `append()` to add one item to the end.","help":{"concept":"`append(value)` mutates the original list by adding one item to the end.","hint_1":"Use `append()` to add one item to the end.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"numbers = [3, 1, 2]\n\n# Add 10 to the end of the list.\n# Then print the updated list.\n","solutionCode":"numbers = [3, 1, 2]\nnumbers.append(10)\nprint(numbers)\n","sourceChecks":{"0":{"message":"Use numbers.append(10) so the list is really changed."}}},"try-list-methods-and-mutation-sketch0":{"title":"Correct one score","prompt":"A score was entered incorrectly. Read the corrected score from input. Use indexed assignment on the existing `scores` list to replace its last item with that value, then print the updated list.","hint":"Use list indexing on the left side of an assignment to change the final item of `scores`. Any valid index expression that selects the last item is acceptable.","help":{"concept":"Indexed assignment changes an existing list item in place. The index expression inside the brackets can be written in different valid ways.","hint_1":"Write an assignment to `scores[...]` where the expression inside the brackets selects the final item.","hint_2":"Assign `corrected_score` to that indexed position, then print `scores` itself."},"starterCode":"corrected_score = int(input())\nscores = [12, 15, 18]\n\n# Replace the last score with corrected_score.\n# Then print the updated list.\n","solutionCode":"corrected_score = int(input())\nscores = [12, 15, 18]\n\nscores[2] = corrected_score\nprint(scores)\n","sourceChecks":{"0":{"message":"Use indexed assignment on the existing `scores` list: assign `corrected_score` to a `scores[...]` position that selects the last item."},"1":{"message":"Print the updated `scores` list itself after changing it."}}},"try-list-methods-and-mutation-sketch1":{"title":"Add a new attendee","prompt":"A new attendee name arrives as input. Add that name to the end of `attendees` with `append()`, then print the updated list.","hint":"Pass the input variable to `attendees.append(...)`.","help":{"concept":"`append(value)` adds exactly one new item to the end of the existing list.","hint_1":"Do not type the incoming name directly into the list; use the value stored in `new_attendee`.","hint_2":"Call `attendees.append(new_attendee)`, then print `attendees`."},"starterCode":"new_attendee = input()\nattendees = [\"Ava\", \"Noah\"]\n\n# Add new_attendee to the end of attendees.\n# Then print the updated list.\n","solutionCode":"new_attendee = input()\nattendees = [\"Ava\", \"Noah\"]\n\nattendees.append(new_attendee)\nprint(attendees)\n","sourceChecks":{"0":{"message":"Use `append()` because that method is explicitly required by the prompt."},"1":{"message":"Print the updated `attendees` list itself after using `append()`."}}},"try-list-methods-and-mutation-sketch2":{"title":"Remove a canceled workshop","prompt":"One workshop has been canceled. Read its name from input, remove that matching value from `workshops` with `remove()`, then print the remaining workshops.","hint":"`remove(value)` searches for a matching value and deletes the first match.","help":{"concept":"`remove(value)` changes the list by deleting the first item equal to that value.","hint_1":"Use the input stored in `canceled` rather than hard-coding one workshop name.","hint_2":"Call `workshops.remove(canceled)`, then print `workshops`."},"starterCode":"canceled = input()\nworkshops = [\"Python\", \"Excel\", \"SQL\", \"Git\"]\n\n# Remove the workshop whose name is stored in canceled.\n# Then print the updated list.\n","solutionCode":"canceled = input()\nworkshops = [\"Python\", \"Excel\", \"SQL\", \"Git\"]\n\nworkshops.remove(canceled)\nprint(workshops)\n","sourceChecks":{"0":{"message":"Use `remove()` because that method is explicitly required by the prompt."},"1":{"message":"Print the mutated `workshops` list itself after removing the canceled workshop."}}},"sc-index-assignment":{"title":"Replace one list item","prompt":"The list is `tasks = [\"email\", \"meeting\", \"backup\"]`. Which line replaces the second item with `\"study\"`?","hint":"Reading an item uses an index. Replacing an item uses that same indexed position on the left side of `=`.","help":{"concept":"Assigning to `list[index]` changes the item stored at that position.","hint_1":"The second item is at index `1` because Python starts counting at 0.","hint_2":"Use `tasks[1] = \"study\"`."},"options":{"a":"tasks[1] = \"study\"","b":"tasks[0] = \"study\"","c":"tasks.append(\"study\")","d":"tasks(1) = \"study\""}},"mc-mutates-original":{"title":"Operations that mutate a list","prompt":"Which operations change the existing list itself? Assume `items` is already a list. Choose all that apply.","hint":"Think about whether the list's stored items are different after the operation runs.","help":{"concept":"Index assignment and list methods such as `append`, `remove`, `pop`, and `sort` mutate the existing list.","hint_1":"`len(items)` reads information but does not change any item.","hint_2":"Choose the operations that replace, add, remove, or reorder list items."},"options":{"a":"items[0] = \"new\"","b":"items.append(\"new\")","c":"items.pop()","d":"len(items)"}},"sc-remove-vs-pop":{"title":"Remove by position and keep the value","prompt":"You need to remove the item at index `1` from `colors` and store the removed value in `removed`. Which line does both?","hint":"`remove()` looks for a matching value. `pop()` removes by position and returns what it removed.","help":{"concept":"`pop(index)` removes the item at that index and returns the removed value.","hint_1":"The task gives a position, not a value to search for.","hint_2":"Assign the result of `colors.pop(1)` to `removed`."},"options":{"a":"removed = colors.pop(1)","b":"removed = colors.remove(1)","c":"colors.remove(removed)","d":"removed = colors[1]"}},"sc-sort-return":{"title":"What sort() returns","prompt":"What is printed by this code?\n\n`scores = [8, 3, 5]`\n`result = scores.sort()`\n`print(result)`","hint":"`sort()` changes `scores` in place; it does not return the sorted list.","help":{"concept":"`list.sort()` mutates the list and returns `None`.","hint_1":"After sorting, `scores` is ordered, but `result` receives the method's return value.","hint_2":"That return value is `None`."},"options":{"a":"None","b":"[3, 5, 8]","c":"8","d":"Nothing is printed because the program crashes"}},"try-list-methods-and-mutation-sketch3":{"title":"Take the second ticket","prompt":" Use `pop()` with the index of the second item, store the removed ticket in `next_ticket`, then print the removed value. Do not hard-code the ticket.","hint":"`pop(1)` removes the item at index 1 and returns that removed item.","help":{"concept":"`pop(index)` is useful when you know the position and also need the removed value.","hint_1":"Assign the result of `tickets.pop(1)` to `next_ticket`.","hint_2":"Print `next_ticket` first, then print `tickets`."},"starterCode":"tickets = [\"T-104\", \"T-105\", \"T-106\", \"T-107\"]\n\n# Remove the second ticket with pop(1) and store it in next_ticket.\n# Print next_ticket.\n# Then print the remaining tickets list.\n","solutionCode":"tickets = [\"T-104\", \"T-105\", \"T-106\", \"T-107\"]\n\nnext_ticket = tickets.pop(1)\nprint(next_ticket)\nprint(tickets)\n","sourceChecks":{"0":{"message":"Use `pop()` because that method is explicitly required by the prompt."},"1":{"message":"Print `next_ticket` itself instead of typing the known removed ticket."},"2":{"message":"Print the remaining `tickets` list itself after `pop()` changes it."}}},"try-list-methods-and-mutation-sketch4":{"title":"Sort three incoming times","prompt":"Three completion times arrive as integers. Store them in a list named `times`, sort the same list from smallest to largest with `sort()`, then print the sorted list.","hint":"Create `times` from the three input variables before calling `times.sort()`.","help":{"concept":"`sort()` rearranges the existing list in ascending order.","hint_1":"Build one list from `first`, `second`, and `third` in that order.","hint_2":"Call `times.sort()` before printing `times`."},"starterCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\n# Create a list named times from the three inputs.\n# Sort times from smallest to largest.\n# Print the sorted list.\n","solutionCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\ntimes = [first, second, third]\ntimes.sort()\nprint(times)\n","sourceChecks":{"0":{"message":"Use `sort()` because that method is explicitly required by the prompt."},"1":{"message":"Print the sorted `times` list itself after sorting it in place."}}}},"tryIt":{"try_list_methods_and_mutation_checkpoint":{"title":"Try it yourself","prompt":"Start with `numbers = [3, 1, 2]`. Add `10` to the end of the list, then print the updated list."},"try_list_methods_and_mutation_sketch0":{"title":"Try it yourself","prompt":"A score was entered incorrectly. Read the corrected score from input, replace the last item in `scores` with that value, then print the updated list."},"try_list_methods_and_mutation_sketch1":{"title":"Try it yourself","prompt":"A new attendee name arrives as input. Add that name to the end of `attendees` with `append()`, then print the updated list."},"try_list_methods_and_mutation_sketch2":{"title":"Try it yourself","prompt":"One workshop has been canceled. Read its name from input, remove that matching value from `workshops` with `remove()`, then print the remaining workshops."},"allowReveal":true,"try_list_methods_and_mutation_sketch3":{"title":"Try it yourself","prompt":"The second ticket in `tickets` is ready to be processed. Remove that item with `pop(1)`, store the removed value in `next_ticket`, then print `next_ticket` followed by the remaining list. Use `pop()` with the index of the second item, store the removed ticket in `next_ticket`, then print the removed value. Do not hard-code the ticket."},"try_list_methods_and_mutation_sketch4":{"title":"Try it yourself","prompt":"Three completion times arrive as integers. Store them in a list named `times`, sort the same list from smallest to largest with `sort()`, then print the sorted list."}}},"looping-through-lists":{"label":"Looping Through Lists","summary":"Loop through list items to print values, accumulate totals, build transformed lists, and keep only values that meet a condition.","cards":{"sketch0":{"title":"Processing each item in a list"},"sketch1":{"title":"Building a running total"},"sketch2":{"title":"Building a transformed list"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Filtering items while you loop"}},"quiz":{"sc-loop-item-name":{"title":"What the loop variable holds","prompt":"In this loop, what does `fruit` hold during each iteration?\n\n```python\nfruits = [\"apple\", \"banana\", \"pear\"]\nfor fruit in fruits:\n print(fruit)\n```","hint":"Look at the name immediately after `for`.","help":{"concept":"The loop variable holds one current item from the list at a time.","hint_1":"The list itself is named `fruits`; the singular name `fruit` changes on each pass.","hint_2":"`fruit` is `\"apple\"`, then `\"banana\"`, then `\"pear\"`."},"options":{"a":"The entire fruits list","b":"One current item from fruits","c":"The numeric index of the current item","d":"The number of items in fruits"}},"sc-empty-list-start":{"title":"Start a result list","prompt":"You want to collect new values while looping. Which line correctly creates an empty list named `result`?","hint":"An empty list literal uses square brackets with nothing between them.","help":{"concept":"A common list-building pattern starts with an empty list and appends values during the loop.","hint_1":"Parentheses create a tuple, while square brackets create a list.","hint_2":"Use `result = []`."},"options":{"a":"result = []","b":"result = ()","c":"result = \"\"","d":"print(result)"}},"mc-loop-uses":{"title":"What loops through a list can do","prompt":"Which actions are common reasons to loop through a list? Choose all that apply.","hint":"Think about tasks you repeat once for each item.","help":{"concept":"List loops are used to process each item, such as printing values, checking conditions, or building a new list from transformed items.","hint_1":"A loop is useful when the same action should happen for every item in the list.","hint_2":"Look for choices about repeated processing of items, not choices about changing Python syntax itself."},"options":{"a":"Print each item","b":"Build a new list from changed items","c":"Check whether items meet a condition","d":"Rename Python keywords"}},"mc-good-loop-names":{"title":"Choose clear loop variable names","prompt":"For the list `scores = [88, 91, 76]`, which loop variable names are clear and appropriate? Choose all that apply.","hint":"Trace the code before choosing the option that matches its actual behavior.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"score","b":"item","c":"scores","d":"score_value"}},"dr-build-derived-list":{"title":"Order the steps to build a derived list","prompt":"Arrange these steps in the correct order for building a new list from an existing list.","hint":"Start by creating the new list before the loop begins.","help":{"concept":"To build a derived list, first create an empty list, then loop through the original list, compute each new value, and append it.","hint_1":"The empty list setup happens before any items are processed.","hint_2":"Inside the loop, you first get the current item, then create the changed value, then add it to the result list."},"tokens":{"t1":"Create an empty result list","t2":"Start a loop over the original list","t3":"Compute the changed value for the current item","t4":"Append the changed value to the result list"}},"dr-read-loop-header":{"title":"Read the loop in order","prompt":"Put these parts of the loop statement in the correct order to make a valid Python loop header.","hint":"Focus on the logical order of the parts.","help":{"concept":"Arrange the pieces according to the structure of the statement.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Put the pieces in the order that makes the statement valid."},"tokens":{"t1":"for","t2":"color","t3":"in","t4":"colors","t5":":"}},"fb-append-call":{"title":"Complete the append line","prompt":"Fill in the missing method name to add each changed item to the result list.","hint":"Use the list method that adds one item to the end.","help":{"concept":"Choose the list method that adds one new value to the end during each iteration.","hint_1":"The method is called on the list you are building, like `result.method(value)`.","hint_2":"It is the common list method used in beginner loops to collect new values."},"template":"result.[blank1](number * 2)","choices":["append","add","insert","print"]},"fb-loop-keyword":{"title":"Complete the loop header","prompt":"Fill in the missing keyword to start a loop over a list.","hint":"Use execution order as evidence instead of choosing by familiar wording.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"template":"[blank1] item in items:","choices":["for","if","while","def"]},"ci-print-each-item":{"title":"Print each item in a list","prompt":"A shelter roll call stores three animal names in `animals`. Loop through `animals` and print each name on its own line.\n\nFor example, if the inputs are `cat`, `dog`, and `fox`, your program should print:\n`cat`\n`dog`\n`fox`.","hint":"Build the list from the three input values before the loop starts.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"first = input()\nsecond = input()\nthird = input()\n\nanimals = [first, second, third]\n\n# Loop through animals and print each one.\n","solutionCode":"first = input()\nsecond = input()\nthird = input()\n\nanimals = [first, second, third]\n\nfor animal in animals:\n print(animal)\n","sourceChecks":{"0":{"message":"Use a for loop over animals instead of printing each variable manually."}}},"ci-double-list-function":{"title":"Return a doubled list","prompt":"Write `double_numbers(numbers)` so it builds a new list containing each number doubled, then returns that new list.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def double_numbers(numbers):\n # build and return a new list\n pass","solutionCode":"def double_numbers(numbers):\n result = []\n for number in numbers:\n result.append(number * 2)\n return result"},"ci-count-long-words":{"title":"Count words longer than 4 letters","prompt":"Write `count_long_words(words)` so it returns how many words in the list are longer than 4 letters.","hint":"Read the task \"Count words longer than 4 letters\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def count_long_words(words):\n # return the number of words longer than 4 letters\n pass","solutionCode":"def count_long_words(words):\n count = 0\n for word in words:\n if len(word) > 4:\n count += 1\n return count"},"try-looping-through-lists-checkpoint":{"title":"Loop through names","prompt":"Loop through `names = [\"Ava\", \"Mia\", \"Zoe\"]` and print each name on its own line.","hint":"Use a `for` loop.","help":{"concept":"A `for` loop can visit each value in a list.","hint_1":"Use a `for` loop.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"names = [\"Ava\", \"Mia\", \"Zoe\"]\n\n# Print each name on its own line.\n","solutionCode":"names = [\"Ava\", \"Mia\", \"Zoe\"]\nfor name in names:\n print(name)\n","sourceChecks":{"0":{"message":"Use a for loop over names instead of printing each name manually."}}},"try-looping-through-lists-sketch0":{"title":"Print room labels from input","prompt":"Three room names arrive as input. Store them in a list named `rooms`. Loop through `rooms` and print each room as `Room: <name>` on its own line.","hint":"Build `rooms` first, then use one `for` loop so the same print statement runs for every room.","help":{"concept":"A loop lets one block of code process every item in a list.","hint_1":"Use a singular loop variable such as `room` for one current value from `rooms`.","hint_2":"Inside the loop, print `\"Room:\"` and the current `room`."},"starterCode":"first = input()\nsecond = input()\nthird = input()\n\n# Create a list named rooms from the three inputs.\n# Loop through rooms.\n# Print each item as: Room: <name>\n","solutionCode":"first = input()\nsecond = input()\nthird = input()\n\nrooms = [first, second, third]\nfor room in rooms:\n print(\"Room:\", room)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `rooms` as the prompt requests."}}},"try-looping-through-lists-sketch1":{"title":"Total four delivery times","prompt":"Four delivery times arrive as integers. Store them in a list named `minutes`. Start `total` at 0, loop through `minutes`, add each value into `total`, then print the final total.","hint":"Initialize `total = 0` before the loop, then update it once for each current value.","help":{"concept":"An accumulator stores a result that grows as the loop processes each item.","hint_1":"The loop variable can be named `minute` because it represents one value from `minutes`.","hint_2":"Inside the loop, use `total += minute`. Print `total` after the loop."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\n# Create a list named minutes from the four inputs.\n# Start total at 0.\n# Add each minute value into total with a loop.\n# Print the final total.\n","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\nminutes = [a, b, c, d]\ntotal = 0\nfor minute in minutes:\n total += minute\nprint(total)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `minutes` as the prompt requests."},"1":{"message":"Add each score into total inside the loop."}}},"try-looping-through-lists-sketch2":{"title":"Build adjusted values","prompt":"Three integer readings arrive as input. Store them in `readings`. Create an empty list named `adjusted`, then loop through `readings` and append each value plus 5. Print the completed `adjusted` list.","hint":"The result list starts empty and receives one transformed value during each loop iteration.","help":{"concept":"A transformation loop creates one new value for every item in the original list.","hint_1":"Create `adjusted = []` before the loop.","hint_2":"Inside the loop, use `adjusted.append(reading + 5)`."},"starterCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\n# Create readings from the three inputs.\n# Create an empty list named adjusted.\n# Append each reading plus 5 to adjusted.\n# Print adjusted.\n","solutionCode":"first = int(input())\nsecond = int(input())\nthird = int(input())\n\nreadings = [first, second, third]\nadjusted = []\nfor reading in readings:\n adjusted.append(reading + 5)\nprint(adjusted)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `readings` as the prompt requests."},"1":{"message":"Use doubled.append(...) to build the list."}}},"sc-running-total":{"title":"Update a running total","prompt":"Which line belongs inside this loop to add every score into `total`?\n\n```python\nscores = [4, 7, 3]\ntotal = 0\nfor score in scores:\n # missing line\n```","hint":"The current item is stored in `score`, and the accumulated value is stored in `total`.","help":{"concept":"A running total repeatedly adds the current item to an accumulator variable.","hint_1":"The new total should include the old `total` plus the current `score`.","hint_2":"Use `total += score`."},"options":{"a":"total += score","b":"score += total","c":"total = 0","d":"scores.append(total)"}},"sc-filter-append":{"title":"Append only matching items","prompt":"You want `passing` to contain only scores that are at least 60. Where should `passing.append(score)` run?","hint":"Only matching scores should be appended.","help":{"concept":"Filtering combines a loop with a condition so only selected items are added to the result list.","hint_1":"The append should not run for scores below 60.","hint_2":"Put the append inside `if score >= 60:`."},"options":{"a":"Inside `if score >= 60:`","b":"Before the `for` loop","c":"After the loop finishes","d":"Inside `if score < 60:`"}},"try-looping-through-lists-sketch3":{"title":"Keep only high scores","prompt":"Four scores arrive as integers. Store them in `scores`. Create an empty list named `high_scores`, then loop through `scores` and append only values that are 80 or higher. Print the completed `high_scores` list.","hint":"The append should run only when the current score passes the condition.","help":{"concept":"Filtering keeps some list items and skips others based on a condition.","hint_1":"Inside the loop, check `if score >= 80:`.","hint_2":"Indent `high_scores.append(score)` inside that `if` block."},"starterCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\n# Create scores from the four inputs.\n# Create an empty list named high_scores.\n# Keep only scores that are 80 or higher.\n# Print high_scores.\n","solutionCode":"a = int(input())\nb = int(input())\nc = int(input())\nd = int(input())\n\nscores = [a, b, c, d]\nhigh_scores = []\nfor score in scores:\n if score >= 80:\n high_scores.append(score)\nprint(high_scores)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `scores` as the prompt requests."}}}},"tryIt":{"try_looping_through_lists_checkpoint":{"title":"Try it yourself","prompt":"Loop through `names = [\"Ava\", \"Mia\", \"Zoe\"]` and print each name on its own line."},"try_looping_through_lists_sketch0":{"title":"Try it yourself","prompt":"Three room names arrive as input. Store them in a list named `rooms`. Loop through `rooms` and print each room as `Room: <name>` on its own line."},"try_looping_through_lists_sketch1":{"title":"Try it yourself","prompt":"Four delivery times arrive as integers. Store them in a list named `minutes`. Use a running total in a loop, then print the final total."},"try_looping_through_lists_sketch2":{"title":"Try it yourself","prompt":"Three integer readings arrive as input. Build a new `adjusted` list containing each reading plus 5, then print the completed list."},"allowReveal":true,"try_looping_through_lists_sketch3":{"title":"Try it yourself","prompt":"Four scores arrive as input. Build `high_scores` containing only scores that are 80 or higher, then print the completed list."}}},"module-5-workshop-schedule-project":{"label":"Module 5 Workshop Schedule Project","summary":"Build a community workshop schedule from tuple records, preserve their order in a list, create a direct room lookup, and group workshop names inside room lists.","cards":{"sketch0":{"title":"Plan the schedule data"},"project":{"title":"Workshop Schedule Builder"}},"projectSteps":{"exercise1":{"title":"Expand the ordered schedule"},"exercise2":{"title":"Build a room lookup"},"exercise3":{"title":"Group workshops by room"}},"quiz":{"try-workshop-schedule-sketch0":{"title":"Preview the schedule pattern","prompt":"Create `schedule` as a list containing one tuple: `(\"Python Basics\", \"Room A\")`. Loop through `schedule`, unpack each tuple into `name` and `room`, and print each workshop as `name — room`.","hint":"The outer structure is a list; each item is a two-field tuple that can be unpacked in the loop header.","help":{"concept":"The project will use a list to preserve workshop order and a tuple for each fixed `(name, room)` record.","hint_1":"Start with `schedule = [(\"Python Basics\", \"Room A\")]`.","hint_2":"Use `for name, room in schedule:` and print the two unpacked values."},"starterCode":"# Create schedule as a list containing one (name, room) tuple.\n# Loop through schedule, unpack each tuple, and print: name — room\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","sourceChecks":{"0":{"message":"Use a `for` loop over `schedule` as the prompt requests."}}},"exercise1":{"title":"Expand the ordered schedule","prompt":"Step 1 of 3 starts from the working one-session preview. Read two more workshop names and rooms from input in this order: `name2`, `room2`, `name3`, `room3`. Append `(name2, room2)` and `(name3, room3)` to `schedule`. Keep the existing loop so the complete schedule prints in order as `name — room`, one workshop per line. For this step, add the second and third workshop records to `schedule` using `append()`. Then process the completed schedule with a `for` loop over `schedule`.","hint":"Read the four input values first, append two tuple records, then let the existing loop print the ordered list.","help":{"concept":"A list preserves workshop order, and `.append()` can add new fixed tuple records without replacing the existing schedule.","hint_1":"Use `schedule.append((name2, room2))` and then append the third record.","hint_2":"Do not hard-code the two new workshop names or rooms; the tests provide different input values."},"starterCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","sourceChecks":{"0":{"message":"Append the second workshop with `schedule.append((name2, room2))`."},"1":{"message":"Append the third workshop with `schedule.append((name3, room3))`."},"2":{"message":"Keep a `for` loop over `schedule` so the finished schedule is processed in order."}}},"exercise2":{"title":"Build a room lookup","prompt":"Step 2 of 3 starts from your completed ordered schedule. Keep that behavior. Create an empty dictionary named `room_lookup`, loop through `schedule`, and store each workshop name as a key in `room_lookup` with its room as the corresponding value. Then read one workshop name into `requested` and look up that workshop in `room_lookup` and print the stored room.","hint":"Build the dictionary from the tuple records instead of writing the room mappings by hand.","help":{"concept":"The ordered list remains useful for the board, while a dictionary gives direct lookup by workshop name.","hint_1":"Initialize `room_lookup = {}` and fill it inside a loop over `schedule`.","hint_2":"After the dictionary is built, read `requested` and print `room_lookup[requested]`."},"starterCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n\nroom_lookup = {}\nfor name, room in schedule:\n room_lookup[name] = room\n\nrequested = input()\nprint(room_lookup[requested])\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"exercise3":{"title":"Group workshops by room","prompt":"Step 3 of 3 starts from the schedule board and direct lookup. Keep both. Build a nested dictionary named `room_sessions` where each room key stores a list of workshop names held in that room. Loop through `schedule`. If the room already exists in `room_sessions`, append the current workshop name to its list; otherwise create a new one-item list. Finally read `room_query` and print `room_sessions[room_query]`.","hint":"Use dictionary membership to decide whether to append to an existing room list or create that list.","help":{"concept":"A dictionary whose values are lists can group several workshop names under the same room key.","hint_1":"Inside the loop, use `if room in room_sessions:` and append `name` to the existing list.","hint_2":"In the `else` branch, create the first list with `room_sessions[room] = [name]`."},"starterCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n\nroom_lookup = {}\nfor name, room in schedule:\n room_lookup[name] = room\n\nrequested = input()\nprint(room_lookup[requested])\n","solutionCode":"schedule = [(\"Python Basics\", \"Room A\")]\n\nname2 = input()\nroom2 = input()\nname3 = input()\nroom3 = input()\n\nschedule.append((name2, room2))\nschedule.append((name3, room3))\n\nfor name, room in schedule:\n print(f\"{name} — {room}\")\n\nroom_lookup = {}\nfor name, room in schedule:\n room_lookup[name] = room\n\nrequested = input()\nprint(room_lookup[requested])\n\nroom_sessions = {}\nfor name, room in schedule:\n if room in room_sessions:\n room_sessions[room].append(name)\n else:\n room_sessions[room] = [name]\n\nroom_query = input()\nprint(room_sessions[room_query])\n","sourceChecks":{"0":{"message":"Use a `for` loop over `schedule` to process each workshop record, as the prompt requests."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}}},"tryIt":{"try_workshop_schedule_sketch0":{"title":"Try it yourself","prompt":"Create a one-workshop schedule as a list of tuples, then loop through it and unpack the record."},"allowReveal":true}},"nested-data-structures":{"label":"Nested Data Structures","summary":"Work with lists of dictionaries, dictionaries inside dictionaries, and lists stored inside dictionaries by accessing, updating, and looping through one layer at a time.","cards":{"sketch0":{"title":"Reading from a list of dictionaries"},"sketch1":{"title":"Reading and updating a nested dictionary"},"sketch2":{"title":"Changing a list stored inside a dictionary"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Looping through a list of records"}},"quiz":{"sc-1":{"title":"Choose the best structure","prompt":"You want to store several products, and each product has a name and a price. Which structure is the best fit?","hint":"Use execution order as evidence instead of choosing by familiar wording.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"A single string with all product names","b":"A list of dictionaries","c":"One number for each product","d":"A tuple with only one product"}},"sc-2":{"title":"Read a nested value","prompt":"Given `item = {\"name\": \"Pen\", \"info\": {\"price\": 2, \"stock\": 9}}`, which expression gets the value `9`?","hint":"First access the inner dictionary stored at `\"info\"`.","help":{"concept":"To read a nested dictionary value, access the outer key first, then the inner key.","hint_1":"`\"stock\"` is not at the top level of `item`; it is inside `item[\"info\"]`.","hint_2":"The correct expression uses two bracket lookups in order: outer key, then inner key."},"options":{"a":"item[\"stock\"]","b":"item[\"info\"][\"stock\"]","c":"item[\"name\"][\"stock\"]","d":"item[0][\"stock\"]"}},"mc-1":{"title":"Valid nested structures","prompt":"Which of these are examples of nested data structures in Python? Choose all that apply.","hint":"A structure is nested when one collection is stored inside another.","help":{"concept":"Nested data structures contain collections inside collections, such as a list inside a dictionary or dictionaries inside a list.","hint_1":"Check whether each option includes one container placed inside another container.","hint_2":"A plain number or plain string alone is not nested; combinations like list-of-dicts or dict-with-list are."},"options":{"a":"[{\"name\": \"Ava\"}, {\"name\": \"Ben\"}]","b":"{\"scores\": [10, 20, 30]}","c":"42","d":"\"hello\""}},"mc-2":{"title":"Useful access patterns","prompt":"Suppose `players = [{\"name\": \"Mia\", \"points\": 7}, {\"name\": \"Leo\", \"points\": 5}]`. Which expressions are valid ways to read data from this structure? Choose all that apply.","hint":"Start by deciding whether you need a list index first or a dictionary key first.","help":{"concept":"For a list of dictionaries, you use a numeric index to choose one dictionary, then a string key to read a value from that dictionary.","hint_1":"`players` is a list first, so expressions that begin with a string key on `players` are not correct.","hint_2":"Look for expressions that use `[0]` or `[1]` before `['name']` or `['points']`."},"options":{"a":"players[0][\"name\"]","b":"players[1][\"points\"]","c":"players[\"name\"]","d":"players[0][0]"}},"dr-1":{"title":"Access a city name","prompt":"Put these tokens in order to build the expression that gets `\"Paris\"` from `trip = {\"destination\": {\"city\": \"Paris\"}}`.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"trip","t2":"[\"destination\"]","t3":"[\"city\"]"}},"dr-2":{"title":"Build a loop over records","prompt":"Arrange these lines to make a loop that prints each student's name from `students`, a list of dictionaries.","hint":"The loop header comes first, and the indented print line comes after it.","help":{"concept":"To loop through a list of dictionaries, write a `for` loop that takes one dictionary at a time, then access a key from that dictionary inside the loop.","hint_1":"Use `student` as the loop variable for each dictionary in `students`.","hint_2":"After the loop header, the print line should use `student[\"name\"]`."},"tokens":{"t1":"for student in students:","t2":"print(student[\"name\"])"}},"fb-1":{"title":"Fill the missing key","prompt":"Complete the expression so it reads the score from the first dictionary in the list.","hint":"The first part `records[0]` gives you one dictionary.","help":{"concept":"After selecting one dictionary from a list, use the correct key name to read the needed value.","hint_1":"You already have the first record. Now choose the key that stores the numeric result.","hint_2":"Use the dictionary key that names the requested field, not a list index or an unrelated variable."},"template":"records[0][\"[blank1]\"]","choices":["score","records","0","name"]},"fb-2":{"title":"Fill the missing outer key","prompt":"Complete the expression so it reads the list stored inside the dictionary `data = {\"items\": [1, 2, 3]}`.","hint":"You need the key that points to the inner list.","help":{"concept":"When a dictionary stores a list, you use the dictionary key first to get that list.","hint_1":"The list `[1, 2, 3]` is stored under one named key in `data`.","hint_2":"Choose the key that matches the label attached to the list value."},"template":"data[\"[blank1]\"]","choices":["items","data","list","0"]},"code-1":{"title":"Return all names","prompt":"Each item in `records` stores a person's data. Finish `get_names(records)` by adding every record's `\"name\"` value to the `names` list, then return `names`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def get_names(records):\n names = []\n # add each record's name to names\n return names","solutionCode":"def get_names(records):\n names = []\n for record in records:\n names.append(record[\"name\"])\n return names"},"code-2":{"title":"Count total stock","prompt":"Finish `total_stock(items)` so it loops through the item dictionaries, adds each `\"stock\"` value into `total`, and returns the final total.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def total_stock(items):\n total = 0\n # update total using each item's stock\n return total","solutionCode":"def total_stock(items):\n total = 0\n for item in items:\n total += item[\"stock\"]\n return total"},"code-3":{"title":"Find the highest score","prompt":"Finish `highest_score(players)` so it compares each later player's `\"score\"` with `best` and returns the highest score in the list.","hint":"Read the task \"Find the highest score\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def highest_score(players):\n best = players[0][\"score\"]\n # compare later scores with best\n return best","solutionCode":"def highest_score(players):\n best = players[0][\"score\"]\n for player in players:\n if player[\"score\"] > best:\n best = player[\"score\"]\n return best"},"try-nested-data-structures-checkpoint":{"title":"Read nested data","prompt":"Use a list of dictionaries. Print the second student’s name and score.","hint":"Use index `1`, then dictionary keys.","help":{"concept":"Nested data combines containers, such as a list of dictionaries.","hint_1":"Use index `1`, then dictionary keys.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"students = [{\"name\": \"Ava\", \"score\": 88}, {\"name\": \"Mia\", \"score\": 91}]\n\n# Print Mia and her score on separate lines.\n","solutionCode":"students = [{\"name\": \"Ava\", \"score\": 88}, {\"name\": \"Mia\", \"score\": 91}]\nprint(students[1][\"name\"])\nprint(students[1][\"score\"])\n","sourceChecks":{"0":{"message":"Use students[1] to reach Mia instead of typing Mia directly."},"1":{"message":"Use the name key from the student dictionary."},"2":{"message":"Use the score key from the student dictionary."}}},"try-nested-data-structures-sketch0":{"title":"Build records and read the second score","prompt":"Two student names and scores arrive as input. Build `students` as a list containing two dictionaries. Each dictionary must use the keys `\"name\"` and `\"score\"`. Then print the second student's name and score on separate lines by accessing `students[1]` first.","hint":"Build the two dictionaries inside one list, then access the second record with index `1`.","help":{"concept":"A list of dictionaries combines positional access for the outer list with key access for each record.","hint_1":"Create `students = [{\"name\": name1, \"score\": score1}, {\"name\": name2, \"score\": score2}]`.","hint_2":"Print `students[1][\"name\"]` and `students[1][\"score\"]`."},"starterCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\n# Build students as a list of two dictionaries.\n# Print the second student's name using students[1].\n# Print the second student's score using students[1].\n","solutionCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\nstudents = [\n {\"name\": name1, \"score\": score1},\n {\"name\": name2, \"score\": score2}\n]\nprint(students[1][\"name\"])\nprint(students[1][\"score\"])\n","sourceChecks":{"0":{"message":"Use index `1` as requested in the prompt."},"1":{"message":"Use index `1` as requested in the prompt."}}},"try-nested-data-structures-sketch1":{"title":"Update stock inside a nested dictionary","prompt":"The dictionary `product` contains an inner dictionary under the key `\"details\"`. Read a new stock count from input, update only `product[\"details\"][\"stock\"]`, then print the updated stock value.","hint":"Use one key lookup to reach `details`, then another key lookup to reach `stock`.","help":{"concept":"Nested assignment follows the same path as nested reading, with the final lookup placed on the left side of `=`.","hint_1":"Do not replace the whole `details` dictionary.","hint_2":"Assign with `product[\"details\"][\"stock\"] = new_stock`."},"starterCode":"product = {\n \"name\": \"Notebook\",\n \"details\": {\"price\": 4, \"stock\": 12}\n}\nnew_stock = int(input())\n\n# Update only the nested stock value.\n# Print the updated stock value.\n","solutionCode":"product = {\n \"name\": \"Notebook\",\n \"details\": {\"price\": 4, \"stock\": 12}\n}\nnew_stock = int(input())\n\nproduct[\"details\"][\"stock\"] = new_stock\nprint(product[\"details\"][\"stock\"])\n","sourceChecks":{"0":{"message":"Loop through students instead of typing each line directly."},"1":{"message":"Use the name key while building each line."},"2":{"message":"Use the score key while building each line."}}},"try-nested-data-structures-sketch2":{"title":"Add an attendee to a nested list","prompt":"The dictionary `course` stores a list of student names under the key `\"students\"`. Read one new name from input, append that name to `course[\"students\"]`, then print the updated list. Access the student list stored inside `course` under the `students` key, then use `append()` to add `new_student` to that nested list.","hint":"First access the list stored under `\"students\"`, then call `.append()` on that list.","help":{"concept":"When a dictionary value is a list, you can access that list by key and use normal list methods on it.","hint_1":"The input name is stored in `new_student`.","hint_2":"Use `course[\"students\"].append(new_student)`, then print `course[\"students\"]`."},"starterCode":"course = {\"title\": \"Python\", \"students\": [\"Ava\"]}\nnew_student = input()\n\n# Append new_student to the list stored under \"students\".\n# Print the updated students list.\n","solutionCode":"course = {\"title\": \"Python\", \"students\": [\"Ava\"]}\nnew_student = input()\n\ncourse[\"students\"].append(new_student)\nprint(course[\"students\"])\n","sourceChecks":{"0":{"message":"Access the explicitly requested `\"students\"` field from `course`."},"1":{"message":"Use `append()` to add the input name to the nested students list."},"2":{"message":"Print the updated student list stored at `course[\"students\"]` itself."}}},"sc-best-structure":{"title":"Choose a structure for repeated records","prompt":"You need to store several products, and every product has a `name` and a `price`. Which structure best represents that data?","hint":"You need one collection for the whole group and labeled fields for each individual product.","help":{"concept":"A list of dictionaries is a common structure for several records that share the same labeled fields.","hint_1":"The outer list stores all products.","hint_2":"Each dictionary can store one product with keys such as `\"name\"` and `\"price\"`."},"options":{"a":"A list of dictionaries","b":"One long string","c":"A single dictionary for every product combined","d":"One integer"}},"sc-list-then-key":{"title":"Read from a list of dictionaries","prompt":"Given `players = [{\"name\": \"Mia\", \"score\": 7}, {\"name\": \"Leo\", \"score\": 5}]`, which expression gets Leo's score?","hint":"Select the second dictionary first, then read its `\"score\"` key.","help":{"concept":"For a list of dictionaries, access happens in layers: list index first, dictionary key second.","hint_1":"Leo is the second list item, so use index `1`.","hint_2":"Then use `['score']` on that dictionary."},"options":{"a":"players[1][\"score\"]","b":"players[\"score\"][1]","c":"players[1][1]","d":"players[\"Leo\"][\"score\"]"}},"sc-dict-then-key":{"title":"Read from a dictionary inside a dictionary","prompt":"Given `item = {\"name\": \"Pen\", \"info\": {\"price\": 2, \"stock\": 9}}`, which expression gets the stock value?","hint":"Open the outer `\"info\"` field before reading `\"stock\"` from the inner dictionary.","help":{"concept":"A dictionary nested inside another dictionary is read with one key lookup per layer.","hint_1":"`item[\"info\"]` gives the inner dictionary.","hint_2":"Then add `[\"stock\"]`."},"options":{"a":"item[\"info\"][\"stock\"]","b":"item[\"stock\"]","c":"item[0][\"stock\"]","d":"item[\"name\"][\"stock\"]"}},"sc-loop-record":{"title":"Understand the loop variable","prompt":"If `students` is a list of dictionaries, what does `student` hold during `for student in students:`?","hint":"The loop visits one item from the outer list at a time.","help":{"concept":"When a list contains dictionaries, the loop variable receives one whole dictionary record on each iteration.","hint_1":"`student` is not only a name or score.","hint_2":"Inside the loop you can read fields such as `student[\"name\"]`."},"options":{"a":"One student dictionary at a time","b":"Only the student's name","c":"Only the list index","d":"The entire students list every time"}},"try-nested-data-structures-sketch3":{"title":"Loop through dynamic student records","prompt":"Two student names and scores arrive as input. Build `students` as a list of two dictionaries using the keys `\"name\"` and `\"score\"`. Loop through `students` so `student` receives one dictionary at a time. Print each record exactly as `name: score`.","hint":"Build the records first, then use one loop over `students` and read both keys from the current `student`.","help":{"concept":"A loop over a list of dictionaries processes one whole record per iteration.","hint_1":"Use `for student in students:`.","hint_2":"Inside the loop, print `f\"{student['name']}: {student['score']}\"`."},"starterCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\n# Build students as a list of two dictionaries.\n# Loop through students.\n# Print each student as: name: score\n","solutionCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\nstudents = [\n {\"name\": name1, \"score\": score1},\n {\"name\": name2, \"score\": score2}\n]\nfor student in students:\n print(f\"{student['name']}: {student['score']}\")\n","sourceChecks":{"0":{"message":"Use a `for` loop over `students` as the prompt requests."}}}},"tryIt":{"try_nested_data_structures_checkpoint":{"title":"Try it yourself","prompt":"Use a list of dictionaries. Print the second student’s name and score."},"try_nested_data_structures_sketch0":{"title":"Try it yourself","prompt":"Build two student dictionaries inside a list, then read the second record by index and key."},"try_nested_data_structures_sketch1":{"title":"Try it yourself","prompt":"Update a stock value stored inside a nested dictionary."},"try_nested_data_structures_sketch2":{"title":"Try it yourself","prompt":"The dictionary `course` stores a list of student names under the key `\"students\"`. Read one new name from input, append that name to `course[\"students\"]`, then print the updated list. Access the student list stored inside `course` under the `students` key, then use `append()` to add `new_student` to that nested list."},"allowReveal":true,"try_nested_data_structures_sketch3":{"title":"Try it yourself","prompt":"Build student records from input and loop through the list one dictionary at a time."}}},"tuple-records-and-unpacking":{"label":"Tuple Records and Unpacking","summary":"Use tuples for fixed-shape records, read fields by position, unpack fields into meaningful names, and process tuple records in a loop.","cards":{"sketch0":{"title":"Tuples as fixed-shape records"},"sketch1":{"title":"Unpacking fields into names"},"quiz":{"title":"Check your understanding"},"sketch2":{"title":"Looping through tuple records"}},"quiz":{"try-tuple-records-sketch0":{"title":"Build and read a shipment record","prompt":"A product name and quantity arrive as input. Create a tuple named `shipment` containing `product` first and `quantity` second. Then print the product using index `0` and the quantity using index `1`, each on its own line. Create a tuple named `shipment` containing `product` first and `quantity` second. Then use tuple indexing to read and print the first field followed by the second field.","hint":"Create one two-field tuple from the input variables, then read its two positions.","help":{"concept":"A tuple can hold related fields in a fixed order, and tuple indexes work like list indexes.","hint_1":"Build `shipment = (product, quantity)`.","hint_2":"Print `shipment[0]`, then `shipment[1]`."},"starterCode":"product = input()\nquantity = int(input())\n\n# Create shipment as a two-field tuple: product, then quantity.\n# Print the product using index 0.\n# Print the quantity using index 1.\n","solutionCode":"product = input()\nquantity = int(input())\n\nshipment = (product, quantity)\nprint(shipment[0])\nprint(shipment[1])\n","sourceChecks":{"0":{"message":"Create `shipment` as the tuple `(product, quantity)`."},"1":{"message":"Use index `0` to read the first tuple field."},"2":{"message":"Use index `1` to read the second tuple field."}}},"try-tuple-unpacking-sketch1":{"title":"Unpack a booking record","prompt":"A booking record is already stored as the provided `booking` value is a three-field tuple containing a workshop title, seat count, and day. Unpack the tuple into `title`, `seats`, and `day` in one assignment. Print the three variables on separate lines in that order. Unpack `booking` into the variables `title`, `seats`, and `day` in that order before printing the three values. Do not hard-code the known output.","hint":"The tuple has three fields, so use three target names on the left side of one assignment.","help":{"concept":"Unpacking replaces positional lookups with meaningful variable names.","hint_1":"Write `title, seats, day = booking`.","hint_2":"After unpacking, print `title`, `seats`, and `day` instead of hard-coding the values."},"starterCode":"booking = (\"Workshop\", 24, \"Friday\")\n\n# Unpack booking into title, seats, and day.\n# Print title, seats, and day on separate lines.\n","solutionCode":"booking = (\"Workshop\", 24, \"Friday\")\n\ntitle, seats, day = booking\nprint(title)\nprint(seats)\nprint(day)\n","sourceChecks":{"0":{"message":"Unpack the tuple with `title, seats, day = booking` before printing the fields."}}},"sc-tuple-purpose":{"title":"Choose a fixed-shape record","prompt":"A coordinate always has exactly two ordered fields: x and y. Which value best communicates that fixed two-field shape?","options":{"a":"[4, 9]","b":"(4, 9)","c":"{\"x\": 4, \"y\": 9}","d":"\"4, 9\""},"hint":"Use the collection type intended for an ordered record whose fields should not be changed in place.","help":{"concept":"A tuple is useful when a small ordered record has a stable shape.","hint_1":"A list is better when items are expected to be added, removed, or replaced.","hint_2":"Choose the value written with parentheses."}},"mc-tuple-facts":{"title":"Recognize tuple behavior","prompt":"Which statements about tuples are true?","options":{"a":"Tuple positions use zero-based indexes.","b":"append() adds a value to an existing tuple.","c":"A tuple can be unpacked into multiple names.","d":"Tuples can contain only strings."},"hint":"Separate how a tuple is read from whether its structure can be mutated.","help":{"concept":"Tuples are ordered and indexable, but they do not support list-style mutation methods.","hint_1":"Unpacking follows position order.","hint_2":"A tuple may hold values of different types."}},"fb-tuple-index":{"title":"Read the first tuple field","prompt":"Complete the expression that reads `\"North\"` from `direction = (\"North\", 12)`: `direction[___]`","options":{"a":"0","b":"1","c":"-2 + 1"},"hint":"Tuple indexing begins at the same position as list and string indexing.","help":{"concept":"Every Python sequence begins with the zero index.","hint_1":"The requested value is the first field.","hint_2":"Use the simplest direct index."}},"dr-tuple-unpack":{"title":"Build an unpacking assignment","prompt":"Arrange the tokens to unpack `record` into `name` and `score`.","tokens":{"t1":"name","t2":",","t3":"score","t4":"=","t5":"record"},"hint":"Put the target names on the left and the tuple variable on the right.","help":{"concept":"Unpacking is one assignment with one target name per tuple position.","hint_1":"The comma separates the two target names.","hint_2":"The tuple variable appears after the equals sign."}},"sc-tuple-immutable":{"title":"Recognize an invalid tuple mutation","prompt":"Given `point = (4, 9)`, which line tries to mutate the tuple and therefore cannot be used?","hint":"Tuples can be read and unpacked, but their existing positions cannot be reassigned.","help":{"concept":"Tuple values are ordered and indexable, but the tuple itself is immutable.","hint_1":"`point[0]` can be read.","hint_2":"Assigning a new value to `point[0]` attempts to change the tuple in place."},"options":{"a":"print(point[0])","b":"x, y = point","c":"point[0] = 7","d":"print(point)"}},"sc-unpack-shape":{"title":"Match names to tuple fields","prompt":"Given `student = (\"Ava\", 91, \"A\")`, which line correctly unpacks all three fields?","hint":"Unpacking needs one target name for each tuple position.","help":{"concept":"Tuple unpacking assigns positions from left to right into the same number of target names.","hint_1":"This tuple contains three fields.","hint_2":"Choose the assignment with three names on the left side."},"options":{"a":"name, score, grade = student","b":"name, score = student","c":"student = name, score, grade","d":"name = student"}},"sc-loop-unpack":{"title":"Unpack each record in a loop","prompt":"Given `registrations = [(\"Ava\", 2), (\"Noah\", 1)]`, which loop header gives meaningful names to both fields of each tuple?","hint":"Each item in `registrations` is a two-field tuple.","help":{"concept":"A `for` loop can unpack each tuple item directly into one variable per field.","hint_1":"Each record contains a name and a seat count.","hint_2":"Use `for name, seats in registrations:`."},"options":{"a":"for name, seats in registrations:","b":"for registrations in name, seats:","c":"for name in seats:","d":"for 0, 1 in registrations:"}},"try-tuple-loop-sketch2":{"title":"Build and loop through registration records","prompt":"Two registrations arrive as a name followed by a seat count. Create `registrations` as a list containing two tuples: `(name1, seats1)` and `(name2, seats2)`. Loop through the list by unpacking each tuple into `name` and `seats`, then print `name` and `seats` on one line for each registration.","hint":"Build a list of two tuple records first, then unpack each record directly in the `for` loop header.","help":{"concept":"A list can hold several fixed-shape tuple records, and a loop can unpack each record as it visits it.","hint_1":"Create `registrations = [(name1, seats1), (name2, seats2)]`.","hint_2":"Use `for name, seats in registrations:` and print the two current fields."},"starterCode":"name1 = input()\nseats1 = int(input())\nname2 = input()\nseats2 = int(input())\n\n# Create registrations as a list of two (name, seats) tuples.\n# Loop through registrations and unpack each tuple into name and seats.\n# Print name and seats on one line for each record.\n","solutionCode":"name1 = input()\nseats1 = int(input())\nname2 = input()\nseats2 = int(input())\n\nregistrations = [(name1, seats1), (name2, seats2)]\nfor name, seats in registrations:\n print(name, seats)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `registrations` as the prompt requests."}}}},"tryIt":{"try_tuple_records_sketch0":{"title":"Try it yourself","prompt":"A product name and quantity arrive as input. Create a tuple named `shipment` containing `product` first and `quantity` second. Then print the product using index `0` and the quantity using index `1`, each on its own line. Create a tuple named `shipment` containing `product` first and `quantity` second. Then use tuple indexing to read and print the first field followed by the second field."},"try_tuple_unpacking_sketch1":{"title":"Try it yourself","prompt":"A booking record is already stored as the provided `booking` value is a three-field tuple containing a workshop title, seat count, and day. Unpack the tuple into `title`, `seats`, and `day` in one assignment. Print the three variables on separate lines in that order. Unpack `booking` into the variables `title`, `seats`, and `day` in that order before printing the three values. Do not hard-code the known output."},"allowReveal":true,"try_tuple_loop_sketch2":{"title":"Try it yourself","prompt":"Build two tuple records from input, store them in a list, and unpack each record in a loop."}},"practice":{"practice-unpack-name-score":{"title":"Unpack a name and score record","prompt":"Read a name and a whole-number score. Store them together in a tuple named `record`, unpack the tuple into `name` and `score`, then print `NAME: SCORE`.","hint":"Create `(name_input, score_input)`, then assign `name, score = record`.","help":{"concept":"Tuple unpacking assigns each fixed record field to a matching variable in one statement.","hint_1":"Create `(name_input, score_input)`, then assign `name, score = record`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"name_input = input().strip()\nscore_input = int(input())\n\n# Build record, unpack it, and print NAME: SCORE.\n","starterFiles":{"main_py":{"content":"name_input = input().strip()\nscore_input = int(input())\n\n# Build record, unpack it, and print NAME: SCORE.\n"}},"solutionCode":"name_input = input().strip()\nscore_input = int(input())\nrecord = (name_input, score_input)\nname, score = record\nprint(f\"{name}: {score}\")\n","solutionFiles":{"main_py":{"content":"name_input = input().strip()\nscore_input = int(input())\nrecord = (name_input, score_input)\nname, score = record\nprint(f\"{name}: {score}\")\n"}}},"practice-tuple-first-and-last":{"title":"Read fields from a tuple record","prompt":"Read a city, a day, and a temperature. Store them as `(city, day, temperature)` in `record`, then print the first field and the last field on separate lines using tuple indexes.","hint":"The first field is index `0`; the last field can be accessed with `-1`.","help":{"concept":"A tuple keeps record fields in a stable order, so indexes can retrieve known positions directly.","hint_1":"The first field is index `0`; the last field can be accessed with `-1`.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\n\n# Build record and print its first and last fields.\n","starterFiles":{"main_py":{"content":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\n\n# Build record and print its first and last fields.\n"}},"solutionCode":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\nrecord = (city, day, temperature)\nprint(record[0])\nprint(record[-1])\n","solutionFiles":{"main_py":{"content":"city = input().strip()\nday = input().strip()\ntemperature = int(input())\nrecord = (city, day, temperature)\nprint(record[0])\nprint(record[-1])\n"}}},"practice-loop-unpack-two-records":{"title":"Loop through tuple records with unpacking","prompt":"Read two names and two scores. Build a list containing two `(name, score)` tuples. Loop with `for name, score in records:` and print each record as `NAME -> SCORE`.","hint":"Build two tuples first, then unpack each tuple directly in the `for` loop header.","help":{"concept":"A loop can unpack each tuple record as it is visited, giving clear names to the fields without separate index lookups.","hint_1":"Build two tuples first, then unpack each tuple directly in the `for` loop header.","hint_2":"Run the program and compare the output with the expected example."},"starterCode":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\n\n# Build two tuple records and loop through them with unpacking.\n","starterFiles":{"main_py":{"content":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\n\n# Build two tuple records and loop through them with unpacking.\n"}},"solutionCode":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\nrecords = [(name1, score1), (name2, score2)]\nfor name, score in records:\n print(f\"{name} -> {score}\")\n","solutionFiles":{"main_py":{"content":"name1 = input().strip()\nscore1 = int(input())\nname2 = input().strip()\nscore2 = int(input())\nrecords = [(name1, score1), (name2, score2)]\nfor name, score in records:\n print(f\"{name} -> {score}\")\n"}}}}},"updating-and-looping-dictionaries":{"label":"Updating and Looping Dictionaries","summary":"Add or update dictionary entries, remove keys safely, loop through keys or key-value pairs, and build a dictionary from repeated data.","cards":{"sketch0":{"title":"Adding and updating entries"},"sketch1":{"title":"Removing a key safely"},"sketch2":{"title":"Looping through dictionary keys"},"quiz":{"title":"Check your understanding"},"sketch3":{"title":"Looping through key-value pairs"},"sketch4":{"title":"Building a dictionary in a loop"}},"quiz":{"sc-dict-update-existing":{"title":"Updating an existing key","prompt":"What happens in Python when you run `profile[\"age\"] = 13` and the key `\"age\"` is already in the dictionary?","hint":"Assignment with an existing key replaces that key's old value.","help":{"concept":"Dictionary assignment uses the key to decide where the value goes. If the key already exists, Python keeps the key and changes only its stored value.","hint_1":"This is not a list index operation. Python looks up the key `\"age\"` in the dictionary.","hint_2":"Ask whether the key is new or already present. Existing keys are changed, not duplicated."},"options":{"a":"It updates the value stored for `\"age\"`","b":"It creates a second separate `\"age\"` entry","c":"It removes the `\"age\"` key","d":"It turns the dictionary into a list"}},"sc-loop-direct-dict":{"title":"What direct dictionary iteration gives you","prompt":"If `colors = {\"red\": 1, \"blue\": 2}`, what does `for color in colors:` store in `color` on each iteration?","hint":"A plain loop over a dictionary visits its lookup labels.","help":{"concept":"Direct dictionary iteration yields one key at a time.","hint_1":"The keys are `\"red\"` and `\"blue\"`.","hint_2":"To obtain the matching value inside the loop, you could use `colors[color]`."},"options":{"a":"Each key, such as `\"red\"` and `\"blue\"`","b":"Each value, such as `1` and `2`","c":"A key and value pair automatically","d":"The dictionary length"}},"mc-valid-dict-changes":{"title":"Ways to change a dictionary","prompt":"Which statements can change the contents of a dictionary named `stock`? Choose all that apply.","hint":"Think about adding or updating with square brackets, and removing with `del`.","help":{"concept":"Dictionaries can be changed by assigning to a key or deleting a key. Reading a value or printing the dictionary does not modify it.","hint_1":"Look for statements that either store a value into `stock[...]` or remove a key from `stock`.","hint_2":"One correct choice adds or updates a key, and another correct choice removes a key entirely."},"options":{"a":"`stock[\"pens\"] = 12`","b":"`del stock[\"pens\"]`","c":"`print(stock[\"pens\"])`","d":"`len(stock)`"}},"mc-items-loop":{"title":"Using `.items()`","prompt":"Which statements about `for key, value in data.items():` are correct? Choose all that apply.","hint":"Focus on what `.items()` provides to the loop.","help":{"concept":"The `.items()` method gives key-value pairs, so the loop can unpack each pair into two variables.","hint_1":"Check whether the loop receives one thing or two things from each dictionary entry.","hint_2":"Two statements are true: one about getting both parts of each entry, and one about the meaning of `key` and `value`."},"options":{"a":"It lets you work with both the key and the value in each loop","b":"`key` stores the dictionary key for the current pair","c":"It only works for lists, not dictionaries","d":"It removes entries as it loops"}},"dr-update-sequence":{"title":"Order the dictionary changes","prompt":"Put these lines in the correct order to create a dictionary, update one value, add one new key, and print the result.","hint":"Start by creating the dictionary before trying to change it.","help":{"concept":"A dictionary must exist before you can update or add entries. After the changes, printing shows the final state.","hint_1":"The dictionary literal line comes first, and `print` comes last.","hint_2":"Between those, update the existing `\"tea\"` key and add the new `\"juice\"` key."},"tokens":{"t1":"drinks = {\"tea\": 2}","t2":"drinks[\"tea\"] = 3","t3":"drinks[\"juice\"] = 1","t4":"print(drinks)"}},"dr-loop-items-order":{"title":"Build a loop with `.items()`","prompt":"Arrange the tokens to make a loop that prints each key and value from `scores`.","hint":"The loop header comes first, then the indented print line.","help":{"concept":"A dictionary loop with `.items()` uses `for key, value in scores.items():` and then an indented statement inside the loop.","hint_1":"Use `.items()` in the loop header so both variables receive data.","hint_2":"After the colon, the next line should be indented and print both loop variables."},"tokens":{"t1":"for name, score in scores.items():","t2":"print(name, score)"}},"fb-remove-key":{"title":"Remove a dictionary entry","prompt":"Choose the missing code to remove the key `\"done\"` from the dictionary.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"[blank1] tasks[\"done\"]","choices":["del","print","return","for"]},"fb-items-method":{"title":"Complete the loop method","prompt":"Choose the missing method so the loop gets both keys and values.","hint":"Use the dictionary method that returns key-value pairs.","help":{"concept":"Choose the dictionary method that yields key-value pairs so each pair can be unpacked into two loop variables.","hint_1":"Methods like `.keys()` and `.values()` give only one part each.","hint_2":"You need the method that matches `for key, value in ...`."},"template":"for key, value in data.[blank1]():","choices":["items","keys","values","append"]},"ci-update-score":{"title":"Update one score and return the dictionary","prompt":"Write `update_score(scores, name, new_score)` so it updates the existing entry for `name` or adds it if it is missing, then returns the `scores` dictionary.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def update_score(scores, name, new_score):\n # update or add the score, then return the dictionary\n pass","solutionCode":"def update_score(scores, name, new_score):\n scores[name] = new_score\n return scores"},"ci-remove-key":{"title":"Remove a key if it exists","prompt":"Write `remove_item(data, key_name)` so it removes `key_name` from the dictionary when that key is present, then returns the dictionary.","hint":"Read the task \"Remove a key if it exists\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def remove_item(data, key_name):\n # remove the key when it is present, then return the dictionary\n pass","solutionCode":"def remove_item(data, key_name):\n if key_name in data:\n del data[key_name]\n return data"},"ci-format-items":{"title":"Build lines from dictionary pairs","prompt":"Write `format_inventory(items)` so it builds and returns a list of strings in the format `\"name: count\"`, such as `\"pens: 3\"`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def format_inventory(items):\n # return a list like [\"pens: 3\", \"paper: 2\"]\n result = []\n \n return result","solutionCode":"def format_inventory(items):\n result = []\n for name, count in items.items():\n result.append(f\"{name}: {count}\")\n return result"},"try-updating-and-looping-dictionaries-checkpoint":{"title":"Update and loop through scores","prompt":"Update Mia’s score to `91`, then print each name and score as `name: score`.","hint":"Assign to `scores[\"Mia\"]`, then loop with `.items()`.","help":{"concept":"Dictionaries can be updated by assigning to an existing key.","hint_1":"Assign to `scores[\"Mia\"]`, then loop with `.items()`.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"scores = {\"Ava\": 88, \"Mia\": 79}\n\n# Update Mia to 91.\n# Print each name and score.\n","solutionCode":"scores = {\"Ava\": 88, \"Mia\": 79}\nscores[\"Mia\"] = 91\nfor name, score in scores.items():\n print(f\"{name}: {score}\")\n","sourceChecks":{"0":{"message":"Update scores['Mia'] to 91 instead of printing the final result directly."}}},"try-updating-and-looping-dictionaries-sketch0":{"title":"Add or update stock from input","prompt":"The dictionary `stock` already contains counts for pens and paper. Read an item name and an integer amount from input. Store `amount` under the key in `item` using dictionary assignment, then print the updated dictionary. Your code must work whether the input key already exists or is new. Update `stock` by using the value in `item` as the dictionary key and the value in `amount` as that key's value. This exercise is specifically about dictionary assignment by key.","hint":"Use the input variable itself as the key: `stock[item] = amount`.","help":{"concept":"Dictionary assignment uses the same syntax for both adding a new key and updating an existing one.","hint_1":"Do not write separate code for `\"pens\"` and new item names.","hint_2":"Assign `amount` to `stock[item]`, then print `stock`."},"starterCode":"stock = {\"pens\": 4, \"paper\": 2}\nitem = input()\namount = int(input())\n\n# Store amount under the key in item.\n# Print the updated stock dictionary.\n","solutionCode":"stock = {\"pens\": 4, \"paper\": 2}\nitem = input()\namount = int(input())\n\nstock[item] = amount\nprint(stock)\n","sourceChecks":{"0":{"message":"Store the input amount with `stock[item] = amount` as requested."},"1":{"message":"Print the updated `stock` dictionary itself after changing it."}}},"try-updating-and-looping-dictionaries-sketch1":{"title":"Remove an optional setting","prompt":"The dictionary `settings` contains three keys. Read a key from input. If that key exists, remove it with `del`. If it does not exist, leave the dictionary unchanged. Print the final dictionary.","hint":"Guard the deletion with `if key in settings:`.","help":{"concept":"Checking membership before `del` lets the same program handle present and missing keys safely.","hint_1":"Use `key in settings` as the condition.","hint_2":"Inside the `if` block, write `del settings[key]`. Print the dictionary after the condition."},"starterCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\n# If key exists in settings, remove that entry with del.\n# Print the final settings dictionary.\n","solutionCode":"settings = {\"theme\": \"dark\", \"sound\": True, \"font_size\": 16}\nkey = input()\n\nif key in settings:\n del settings[key]\nprint(settings)\n","sourceChecks":{"0":{"message":"Loop through inventory instead of typing the inventory lines directly."}}},"try-updating-and-looping-dictionaries-sketch2":{"title":"Loop through keys and look up each value","prompt":"The dictionary `inventory` is already defined. Loop directly through `inventory` so the loop variable receives one key at a time. For each key, print the key and its matching value on one line. Use a `for` loop directly over `inventory`. For each key produced by the loop, use dictionary indexing to retrieve and print its matching value.","hint":"Use `for item in inventory:` and retrieve the current value with `inventory[item]`.","help":{"concept":"A direct dictionary loop yields keys; use the current key to look up its value.","hint_1":"The loop header should not call `.items()` in this exercise.","hint_2":"Inside the loop, print `item` and `inventory[item]`."},"starterCode":"inventory = {\"pens\": 3, \"markers\": 2, \"folders\": 5}\n\n# Loop directly through inventory so item receives each key.\n# Print the current key and inventory[item] on one line.\n","solutionCode":"inventory = {\"pens\": 3, \"markers\": 2, \"folders\": 5}\n\nfor item in inventory:\n print(item, inventory[item])\n","sourceChecks":{"0":{"message":"Loop directly over `inventory` instead of typing the known output."},"1":{"message":"Use `inventory[item]` to retrieve each current key's value."},"2":{"message":"Store each length with lengths[word] = len(word)."}}},"sc-add-or-update":{"title":"Use one assignment for add or update","prompt":"What does `stock[item] = amount` do when `item` is used as a dictionary key?","hint":"The same square-bracket assignment works whether the key already exists or not.","help":{"concept":"Dictionary assignment adds a new key when it is missing and updates the value when the key already exists.","hint_1":"Python checks whether the key stored in `item` is already present in `stock`.","hint_2":"A missing key is added; an existing key receives the new value."},"options":{"a":"It adds the key if missing or updates its value if it already exists","b":"It can only add new keys","c":"It can only change existing keys","d":"It removes the key from the dictionary"}},"sc-safe-delete":{"title":"Remove a key only when it exists","prompt":"Which pattern safely removes the key stored in `key` from `settings` only when that key exists?","hint":"Check membership before using `del`.","help":{"concept":"A membership check can guard a deletion so a missing key does not cause an error.","hint_1":"Use `key in settings` as the condition.","hint_2":"Place `del settings[key]` inside that `if` block."},"options":{"a":"if key in settings:\n del settings[key]","b":"if settings[key]:\n del key","c":"settings.remove(key)","d":"del key in settings"}},"sc-items-loop":{"title":"Get keys and values together","prompt":"Which loop header gives both the key and value from each entry in `scores`?","hint":"Use the dictionary method that provides key-value pairs.","help":{"concept":"`.items()` provides each dictionary entry as a key-value pair that can be unpacked into two loop variables.","hint_1":"The loop needs two variables because each item contains two pieces.","hint_2":"Use `for name, score in scores.items():`."},"options":{"a":"for name, score in scores.items():","b":"for name, score in scores:","c":"for score in scores.values, names:","d":"for scores.items() in name, score:"}},"try-updating-and-looping-dictionaries-sketch3":{"title":"Print dynamic score pairs with .items()","prompt":"Two student names and scores arrive as input. Build a dictionary named `scores` from those two pairs. Then loop through the dictionary's `items()` method by unpacking each pair into `name` and `score`. Print each entry exactly as `name: score`.","hint":"Build the dictionary first, then use `for name, score in scores.items():`.","help":{"concept":"`.items()` lets a loop work with the key and value together without a separate lookup.","hint_1":"Create `scores = {name1: score1, name2: score2}`.","hint_2":"In the loop, print `f\"{name}: {score}\"`."},"starterCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\n# Create scores from the two name/score pairs.\n# Loop through scores.items() as name, score.\n# Print each entry as: name: score\n","solutionCode":"name1 = input()\nscore1 = int(input())\nname2 = input()\nscore2 = int(input())\n\nscores = {name1: score1, name2: score2}\nfor name, score in scores.items():\n print(f\"{name}: {score}\")\n","sourceChecks":{"0":{"message":"Use a `for` loop over `scores` as the prompt requests."}}},"try-updating-and-looping-dictionaries-sketch4":{"title":"Build word lengths in a dictionary","prompt":"Three words arrive as input. Store them in a list named `words`. Create an empty dictionary named `lengths`. Loop through `words` and store each word as a key with `len(word)` as its value. Print the completed `lengths` dictionary.","hint":"Inside the loop, assign to a dictionary key with `lengths[word] = len(word)`.","help":{"concept":"A loop can build a dictionary one key-value pair at a time.","hint_1":"Create `words` from the three inputs and initialize `lengths = {}` before the loop.","hint_2":"For each `word`, store its calculated length with `lengths[word] = len(word)`."},"starterCode":"first = input()\nsecond = input()\nthird = input()\n\n# Create words from the three input values.\n# Create an empty dictionary named lengths.\n# Loop through words and store each word's length.\n# Print lengths.\n","solutionCode":"first = input()\nsecond = input()\nthird = input()\n\nwords = [first, second, third]\nlengths = {}\nfor word in words:\n lengths[word] = len(word)\nprint(lengths)\n","sourceChecks":{"0":{"message":"Use a `for` loop over `words` as the prompt requests."}}}},"tryIt":{"try_updating_and_looping_dictionaries_checkpoint":{"title":"Try it yourself","prompt":"Update Mia’s score to `91`, then print each name and score as `name: score`."},"try_updating_and_looping_dictionaries_sketch0":{"title":"Try it yourself","prompt":"The dictionary `stock` already contains counts for pens and paper. Read an item name and an integer amount from input. Store `amount` under the key in `item` using dictionary assignment, then print the updated dictionary. Your code must work whether the input key already exists or is new. Update `stock` by using the value in `item` as the dictionary key and the value in `amount` as that key's value. This exercise is specifically about dictionary assignment by key."},"try_updating_and_looping_dictionaries_sketch1":{"title":"Try it yourself","prompt":"Remove an input key from `settings` only when that key exists."},"try_updating_and_looping_dictionaries_sketch2":{"title":"Try it yourself","prompt":"The dictionary `inventory` is already defined. Loop directly through `inventory` so the loop variable receives one key at a time. For each key, print the key and its matching value on one line. Use a `for` loop directly over `inventory`. For each key produced by the loop, use dictionary indexing to retrieve and print its matching value."},"allowReveal":true,"try_updating_and_looping_dictionaries_sketch3":{"title":"Try it yourself","prompt":"Two student names and scores arrive as input. Build a dictionary named `scores` from those two pairs. Then loop through the dictionary's `items()` method by unpacking each pair into `name` and `score`. Print each entry exactly as `name: score`."},"try_updating_and_looping_dictionaries_sketch4":{"title":"Try it yourself","prompt":"Build a word-length dictionary one entry at a time inside a loop."}}}},"python-6-functions-and-modularity":{"decomposition-and-refactoring":{"label":"Decomposition and Refactoring","summary":"Refactor working code by extracting repeated or separate responsibilities into helper functions while preserving the program's behavior.","cards":{"sketch0":{"title":"Extract repeated work into one helper"},"sketch1":{"title":"Move one responsibility out of the main flow"},"sketch2":{"title":"Reuse helpers instead of duplicating their logic"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-1":{"title":"Best reason to extract a helper","prompt":"Which situation is the strongest reason to move code into a helper function?","hint":"Look for repeated logic that does the same job in more than one place.","help":{"concept":"Helper functions are especially useful when the same logic appears multiple times, because one function can replace repeated code and make updates easier.","hint_1":"Compare the choices and find the one where the same steps would otherwise be copied.","hint_2":"A helper is most valuable when one reusable task appears in several places, not just because a program has many lines."},"options":{"a":"A variable name is short","b":"The same cleanup steps are written in several places","c":"The program uses input() once","d":"A print statement appears at the end"}},"sc-2":{"title":"What refactoring should preserve","prompt":"When you refactor a working program, what should stay the same?","hint":"Refactoring changes structure, not the program's intended result.","help":{"concept":"Refactoring improves readability or organization while preserving behavior, so the program should still produce the same results for the same inputs.","hint_1":"Think about what users notice: the program should still solve the same problem correctly.","hint_2":"The code layout may change, but the output and behavior for the same input should not change."},"options":{"a":"The number of functions must decrease","b":"The variable names must stay identical","c":"The program's behavior for the same input should remain correct","d":"Every line must stay in the same order"}},"mc-1":{"title":"Signs a function is doing too much","prompt":"Which choices suggest a function should be split into smaller helpers? Choose all that apply.","hint":"Look for mixed responsibilities and repeated chunks of logic.","help":{"concept":"A function often needs decomposition when it handles several different jobs or contains repeated logic that could be reused elsewhere.","hint_1":"One clue is that the function both transforms data and formats final output in a long block.","hint_2":"Another clue is seeing nearly identical code chunks or a function that tries to clean, calculate, and display all at once."},"options":{"a":"It cleans text, calculates a result, and formats a message in one long block","b":"It contains repeated code chunks with only small changes","c":"It has one short return statement for one clear task","d":"It is hard to describe the function's job in one sentence"}},"mc-2":{"title":"Benefits of helper functions","prompt":"Which are real benefits of breaking code into helper functions? Choose all that apply.","hint":"Think about readability, reuse, and testing.","help":{"concept":"Helper functions improve organization by giving small tasks clear names, reducing duplication, and making logic easier to test separately.","hint_1":"Useful helpers usually make code easier to read and let you reuse one piece of logic in multiple places.","hint_2":"They also help you test one small behavior at a time; they do not automatically make every program shorter in line count."},"options":{"a":"You can reuse the same logic from multiple places","b":"Small pieces are easier to test one at a time","c":"Every program will always use fewer total lines","d":"Function names can explain what each step does"}},"dr-1":{"title":"Refactor repeated cleanup","prompt":"Put these steps in the best order for refactoring repeated text-cleaning code into a helper function.","hint":"First identify the repeated task, then define the helper, then replace the duplicates.","help":{"concept":"A clean refactor usually starts by noticing repeated logic, extracting it into a function, and then calling that function where needed.","hint_1":"You should not replace old code with helper calls before the helper exists.","hint_2":"The repeated behavior must be identified first, then moved into a function, then used from the original locations."},"tokens":{"t1":"Notice the same cleanup logic appears more than once","t2":"Write a helper function for that cleanup task","t3":"Replace the repeated code with calls to the helper","t4":"Run the program and confirm the behavior still matches"}},"dr-2":{"title":"How a helper-based program flows","prompt":"Arrange the steps in the order they happen when this pattern runs: input is cleaned, then used to build a message, then printed.","hint":"A helper returns a value before the next function uses it.","help":{"concept":"In decomposed code, one function often returns a cleaned value, another function uses that value to build a result, and then the main code prints the final result.","hint_1":"The cleaned text must exist before a greeting or summary can be built from it.","hint_2":"Printing is usually the last step after helper functions have returned the needed values."},"tokens":{"t1":"Call the cleaning helper with the original text","t2":"Receive the cleaned text as a return value","t3":"Use the cleaned text to build the final message","t4":"Print the final message"}},"fb-1":{"title":"Call the helper","prompt":"Choose the function call that uses the helper to clean the variable `name`.","hint":"The blank should be a call that passes `name` into the helper.","help":{"concept":"To use a helper function, write its name followed by parentheses and pass the needed argument inside.","hint_1":"You are filling the right side of an assignment, so the blank should produce a value.","hint_2":"Look for the choice that calls `clean_name` with `name` inside the parentheses."},"template":"nice_name = [blank1]","choices":["clean_name(name)","name = clean_name","print(name)","return clean_name"]},"fb-2":{"title":"Return from a helper","prompt":"Choose the missing word that sends the computed value back from the function.","hint":"Inside a function, one keyword sends a value back to the caller.","help":{"concept":"A helper function should send its result back so other code can store, display, or combine that value.","hint_1":"`print` shows text in the output panel, but it does not send a reusable value back to the caller.","hint_2":"The missing word is the keyword used before an expression like `text.strip()` when the function should produce a value."},"template":"def clean_text(text):\n [blank1] text.strip().lower()","choices":["return","print","input","def"]},"ci-1":{"title":"Extract a cleaning helper","prompt":"Write `clean_name(name)` so it returns the cleaned version of `name`. This helper should do the name-cleaning work instead of leaving it repeated elsewhere.","hint":"Read the task \"Extract a cleaning helper\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def clean_name(name):\n # return the cleaned version of name\n pass","solutionCode":"def clean_name(name):\n return name.strip().title()"},"ci-2":{"title":"Build a summary with helpers","prompt":"Split this job into two helpers. `word_count(text)` should return the number of words, and `summary(text)` should call that helper and return a string like `Words: 3`.","hint":"Read the task \"Build a summary with helpers\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def word_count(text):\n # return the number of words\n pass\n\n\ndef summary(text):\n # return a string like: Words: 3\n pass","solutionCode":"def word_count(text):\n return len(text.split())\n\n\ndef summary(text):\n count = word_count(text)\n return f\"Words: {count}\""},"ci-3":{"title":"Refactor repeated math into helpers","prompt":"Finish `double(number)` and `triple(number)`, then use those helper functions inside `combined_total(a, b)` instead of repeating the math there.","hint":"Read the task \"Refactor repeated math into helpers\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def double(number):\n pass\n\n\ndef triple(number):\n pass\n\n\ndef combined_total(a, b):\n # use the helper functions here\n pass","solutionCode":"def double(number):\n return number * 2\n\n\ndef triple(number):\n return number * 3\n\n\ndef combined_total(a, b):\n return double(a) + triple(b)"},"try-decomposition-and-refactoring-checkpoint":{"title":"Use a helper function","prompt":"Define `clean_title(text)` that strips spaces and title-cases the text. Print the cleaned version of `\" python helper \"`.","hint":"Use `.strip().title()` inside a helper function.","help":{"concept":"Decomposition means moving one clear step into a helper function.","hint_1":"Use `.strip().title()` inside a helper function.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def clean_title(text):\n # Return the cleaned title.\n pass\n\nprint(clean_title(\" python helper \"))\n","solutionCode":"def clean_title(text):\n return text.strip().title()\n\nprint(clean_title(\" python helper \"))\n"},"try-decomposition-and-refactoring-sketch0":{"title":"Refactor repeated name cleanup","prompt":"This program already produces the correct output, but it repeats whitespace trimming followed by title-case normalization for both names. Refactor it without changing the output: define `clean_name(name)` so it returns the cleaned name, then replace both repeated cleanup expressions with calls to `clean_name`.","hint":"The finished program should still print the same two cleaned names; only the structure changes.","help":{"concept":"A refactor can preserve output while moving repeated logic into one reusable helper.","hint_1":"Define `clean_name(name)` once using `name.strip().title()`.","hint_2":"Use `clean_name(first)` and `clean_name(second)` instead of repeating the method chain."},"starterCode":"first = input()\nsecond = input()\n\nfirst_clean = first.strip().title()\nsecond_clean = second.strip().title()\n\nprint(first_clean)\nprint(second_clean)\n","solutionCode":"def clean_name(name):\n return name.strip().title()\n\nfirst = input()\nsecond = input()\n\nfirst_clean = clean_name(first)\nsecond_clean = clean_name(second)\n\nprint(first_clean)\nprint(second_clean)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `clean_name(...)` because that function call is explicitly required by the prompt."},"2":{"message":"Call `clean_name(...)` because that function call is explicitly required by the prompt."}}},"try-decomposition-and-refactoring-sketch1":{"title":"Extract word counting from the main flow","prompt":"This working program counts words directly in the main flow. Refactor it without changing its output: create `word_count(text)` that returns the number of words, then use that helper to compute `count`.","hint":"Move the split-and-count responsibility into `word_count(text)` and leave formatting in the main flow.","help":{"concept":"Decomposition can move one responsibility into a helper while the rest of the program keeps its original job.","hint_1":"Inside `word_count`, return `len(text.split())`.","hint_2":"Replace the inline counting lines with `count = word_count(text)`."},"starterCode":"text = input()\nwords = text.split()\ncount = len(words)\nprint(f\"Words: {count}\")\n","solutionCode":"def word_count(text):\n return len(text.split())\n\ntext = input()\ncount = word_count(text)\nprint(f\"Words: {count}\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `word_count(...)` because that function call is explicitly required by the prompt."}}},"try-decomposition-and-refactoring-sketch2":{"title":"Replace duplicated cleanup with a helper call","prompt":"`clean_name(name)` already owns the cleanup rule. `build_badge(name)` currently duplicates that rule. Refactor `build_badge` so it calls `clean_name(name)` and returns `\"Badge: \" + nice_name`. Keep the program's output unchanged.","hint":"The goal is not a new result; it is to make `build_badge` reuse the existing helper.","help":{"concept":"When one helper already owns a responsibility, another helper should call it instead of copying the same implementation.","hint_1":"Inside `build_badge`, assign `nice_name = clean_name(name)`.","hint_2":"Then return `\"Badge: \" + nice_name`."},"starterCode":"def clean_name(name):\n return name.strip().title()\n\ndef build_badge(name):\n nice_name = name.strip().title()\n return \"Badge: \" + nice_name\n\nname = input()\nprint(build_badge(name))\n","solutionCode":"def clean_name(name):\n return name.strip().title()\n\ndef build_badge(name):\n nice_name = clean_name(name)\n return \"Badge: \" + nice_name\n\nname = input()\nprint(build_badge(name))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"sc-refactor-goal":{"title":"What refactoring should preserve","prompt":"What is the main goal when refactoring code that already works?","hint":"The structure may improve, but the program should still do the same job for the same inputs.","help":{"concept":"Refactoring changes code structure without intentionally changing observable behavior.","hint_1":"Function names and line layout may change.","hint_2":"The same inputs should still produce the same intended results."},"options":{"a":"Improve the structure while preserving the program's behavior","b":"Change the output so the refactor is easy to notice","c":"Remove every function from the program","d":"Keep every original line in exactly the same place"}},"sc-extract-repetition":{"title":"Spot a helper candidate","prompt":"A program uses `name.strip().title()` in four different places. Which refactor best reduces that duplication?","hint":"Move the repeated transformation into one named operation.","help":{"concept":"Repeated logic is a strong candidate for a helper function.","hint_1":"The cleanup should have one definition.","hint_2":"Each old duplicate can then be replaced by a helper call."},"options":{"a":"Create `clean_name(name)` and call it from each place","b":"Copy the cleanup into four more places","c":"Rename all four variables but keep the duplicate cleanup","d":"Add extra print statements around each copy"}},"sc-one-responsibility":{"title":"Give a helper one clear job","prompt":"Which helper has the clearest single responsibility in a program that reads text, counts words, and formats a report?","hint":"A helper is easiest to understand when its name describes one focused task.","help":{"concept":"Decomposition separates distinct jobs so each function has a clear responsibility.","hint_1":"Counting words is one focused transformation.","hint_2":"Reading input, counting, formatting, and printing all at once mixes several responsibilities."},"options":{"a":"`word_count(text)` returns the number of words","b":"`do_everything()` reads input, counts, formats, and prints","c":"`stuff(x)` performs several unrelated actions","d":"`run()` duplicates the whole program twice"}},"sc-helper-reuse":{"title":"Reuse an existing helper","prompt":"`clean_name(name)` already returns a cleaned name. Inside `build_badge(name)`, which line best reuses that existing responsibility?","hint":"Call the helper instead of rewriting its `.strip().title()` logic.","help":{"concept":"Once a responsibility has a helper, other functions should call that helper instead of duplicating its implementation.","hint_1":"The helper call should receive `name`.","hint_2":"Store or use the value returned by `clean_name(name)`."},"options":{"a":"nice_name = clean_name(name)","b":"nice_name = name.strip().title()","c":"clean_name = name","d":"print = clean_name"}}},"tryIt":{"try_decomposition_and_refactoring_checkpoint":{"title":"Try it yourself","prompt":"Define `clean_title(text)` that strips spaces and title-cases the text. Print the cleaned version of `\" python helper \"`."},"try_decomposition_and_refactoring_sketch0":{"title":"Try it yourself","prompt":"This program already produces the correct output, but it repeats whitespace trimming followed by title-case normalization for both names. Refactor it without changing the output: define `clean_name(name)` so it returns the cleaned name, then replace both repeated cleanup expressions with calls to `clean_name`."},"try_decomposition_and_refactoring_sketch1":{"title":"Try it yourself","prompt":"Move one responsibility from the main flow into a helper without changing behavior."},"try_decomposition_and_refactoring_sketch2":{"title":"Try it yourself","prompt":"Replace duplicated helper logic with a call to the helper that already owns that responsibility."},"allowReveal":true}},"defining-and-calling-functions":{"label":"Defining and Calling Functions","summary":"Define reusable no-argument functions, call them after their definitions, and reuse a function by calling it more than once.","cards":{"sketch0":{"title":"Defining a function and calling it"},"sketch1":{"title":"Calling the same function more than once"},"sketch2":{"title":"Putting several statements inside a function"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-function-call":{"title":"Recognize a function call","prompt":"Which line calls a function named `greet`?","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"def greet():","b":"greet()","c":"print = greet","d":"return greet"}},"sc-parameter-meaning":{"title":"Understand a parameter","prompt":"In `def greet(name):`, what is `name`?","hint":"Reject any choice that changes the named values, branch order, or output.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"A printed message","b":"A parameter","c":"A return value","d":"A list"}},"mc-valid-calls":{"title":"Pick the valid function calls","prompt":"A function is defined as `def greet(name):`. Which calls are valid? Choose all correct answers.","hint":"The function expects exactly one argument.","help":{"concept":"When a function has one parameter, each call must provide one argument inside the parentheses.","hint_1":"Check how many values each call passes to `greet(...)`.","hint_2":"Valid calls have exactly one value between the parentheses, not zero and not two."},"options":{"a":"greet(\"Ava\")","b":"greet()","c":"greet(\"Ava\", \"Leo\")","d":"greet(\"Mina\")"}},"mc-return-uses":{"title":"Ways to use a returned value","prompt":"A function `double(x)` returns a number. Which lines use that returned value correctly? Choose all correct answers.","hint":"A returned value can be stored or printed.","help":{"concept":"When a function returns a value, you can place the call anywhere a normal value can be used, such as in an assignment or inside `print(...)`.","hint_1":"Look for lines where `double(4)` is treated like a value.","hint_2":"The correct lines either store the result in a variable or pass the result into another function like `print`."},"options":{"a":"result = double(4)","b":"print(double(4))","c":"return = double(4)","d":"def double(4):"}},"dr-define-then-call":{"title":"Order a simple function program","prompt":"Put these lines in the correct order to define a function and then call it.","hint":"The function must be defined before it is called.","help":{"concept":"Python reads code from top to bottom. A function definition comes first, its body stays indented under it, and the call comes after the definition.","hint_1":"Start with the `def` line, then place the indented body line under it.","hint_2":"After the two definition lines are together, put the function call last."},"tokens":{"t1":"def say_hi():","t2":"print(\"Hi\")","t3":"say_hi()"}},"dr-call-with-argument":{"title":"Order a function with one parameter","prompt":"Arrange the lines to define `show_name` and call it with `\"Ava\"`.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"def show_name(name):","t2":"print(name)","t3":"show_name(\"Ava\")"}},"fb-def-keyword":{"title":"Complete a function definition","prompt":"Choose the word that starts a function definition.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"[blank1] greet():","choices":["def","print","call","return"]},"fb-call-argument":{"title":"Fill in the argument","prompt":"Choose the value that completes the function call.","hint":"The function call should pass the name shown in quotes.","help":{"concept":"An argument is the value placed inside the parentheses when calling a function.","hint_1":"Look at the quotes already shown in the call.","hint_2":"The missing part is the exact text value between the parentheses, including the capital letter."},"template":"greet([blank1])","choices":["\"Ava\"","name","greet","print"]},"ci-make-greeting":{"title":"Write a greeting function","prompt":"Write `make_greeting(name)` so it returns a greeting string for that name.","hint":"Read the task \"Write a greeting function\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_greeting(name):\n # return a greeting string\n pass","solutionCode":"def make_greeting(name):\n return \"Hello, \" + name"},"ci-square-number":{"title":"Return the square","prompt":"Write `square(number)` so it returns the square of `number`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def square(number):\n # return the square of number\n pass","solutionCode":"def square(number):\n return number * number"},"ci-full-name":{"title":"Combine first and last name","prompt":"Write `full_name(first, last)` so it returns the first and last name joined into one string.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def full_name(first, last):\n # return the full name as one string\n pass","solutionCode":"def full_name(first, last):\n return first + \" \" + last"},"try-defining-and-calling-functions-checkpoint":{"title":"Define and call a function","prompt":"Define `say_hello()` so it prints `Hello from a function!`, then call it.","hint":"Put the `print()` inside the function body, then call the function below it.","help":{"concept":"A function groups statements that can be run by calling the function name.","hint_1":"Put the `print()` inside the function body, then call the function below it.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"# Define say_hello() below.\n\n","solutionCode":"def say_hello():\n print(\"Hello from a function!\")\n\nsay_hello()\n","sourceChecks":{"0":{"message":"Define a function named say_hello()."},"1":{"message":"Call say_hello() after defining it."}}},"try-defining-and-calling-functions-sketch0":{"title":"Define and call a message function","prompt":"Define a no-argument function named `show_message()`. Inside the function, print exactly `Functions are reusable!`. After the definition, call `show_message()` once.","hint":"Write the `def` line, indent the `print()` inside it, then place the call after the function body.","help":{"concept":"Defining the function creates the reusable block; calling the function is what makes its body run.","hint_1":"Your first line should be `def show_message():`.","hint_2":"After the indented print line, call `show_message()` with no arguments."},"starterCode":"# Define show_message() so its body prints: Functions are reusable!\n# Then call show_message() once.\n","solutionCode":"def show_message():\n print(\"Functions are reusable!\")\n\nshow_message()\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-defining-and-calling-functions-sketch1":{"title":"Call one function three times","prompt":"The starter already defines `ring_bell()` so one call prints `Ding!`. Below the definition, call `ring_bell()` exactly three times so the program prints three `Ding!` lines.","hint":"Do not copy the `print()` statement. Reuse the function by writing three calls.","help":{"concept":"A function can be reused by calling its name again instead of repeating the statements inside its body.","hint_1":"Leave the function definition unchanged.","hint_2":"Add three separate `ring_bell()` calls below the definition."},"starterCode":"def ring_bell():\n print(\"Ding!\")\n\n# Call ring_bell() exactly three times below.\n","solutionCode":"def ring_bell():\n print(\"Ding!\")\n\nring_bell()\nring_bell()\nring_bell()\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-defining-and-calling-functions-sketch2":{"title":"Put a loop inside a function","prompt":"Define a no-argument function named `show_colors()`. Inside it, create a list named `colors` containing `red`, `blue`, and `green` in that order, loop through `colors`, and print each color. After the definition, call `show_colors()` once.","hint":"The list and the `for` loop both belong inside the indented function body.","help":{"concept":"A function body can contain several statements, including list creation and loops you already know.","hint_1":"Indent both `colors = [...]` and the `for color in colors:` loop under `def show_colors():`.","hint_2":"After the function body ends, call `show_colors()` once."},"starterCode":"# Define show_colors().\n# Inside it, create colors = [\"red\", \"blue\", \"green\"].\n# Loop through colors and print each color.\n# Then call show_colors() once.\n","solutionCode":"def show_colors():\n colors = [\"red\", \"blue\", \"green\"]\n for color in colors:\n print(color)\n\nshow_colors()\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"sc-definition-vs-call":{"title":"Definition or call?","prompt":"Which line calls an already-defined function named `greet`?","hint":"A call uses the function name followed by parentheses, without the `def` keyword.","help":{"concept":"A function definition creates the named block of code; a function call runs that block.","hint_1":"`def greet():` starts the definition.","hint_2":"To run the function later, write `greet()`."},"options":{"a":"def greet():","b":"greet()","c":"print = greet","d":"return greet"}},"sc-function-body-indent":{"title":"Identify the function body","prompt":"Which line correctly belongs inside the body of `def show_message():`?","hint":"Statements inside a function body are indented under the `def` line.","help":{"concept":"Indentation tells Python which statements belong to the function body.","hint_1":"The body line must be indented.","hint_2":"The call itself belongs after the definition, not inside its body."},"options":{"a":" print(\"Ready\")","b":"def print(\"Ready\")","c":"show_message():","d":"return = \"Ready\""}},"sc-call-count":{"title":"Count function calls","prompt":"A function `ping()` prints `Ping` once. If the program contains `ping()` on two separate lines, how many times is `Ping` printed?","hint":"Each function call runs the function body once.","help":{"concept":"Calling the same function repeatedly reuses the same body each time.","hint_1":"The first call runs the print once.","hint_2":"The second call runs that same print once again."},"options":{"a":"Two times","b":"One time","c":"Zero times","d":"The function can only be called once"}},"sc-define-before-call":{"title":"Place the call after the definition","prompt":"Which program order correctly defines `cheer()` before trying to call it?","hint":"Python runs top-level statements from top to bottom.","help":{"concept":"The function name must already be defined by the time Python reaches the call.","hint_1":"Put the `def cheer():` block first.","hint_2":"Place `cheer()` after the indented function body."},"options":{"a":"define `cheer()`, then call `cheer()`","b":"call `cheer()`, then define `cheer()`","c":"call `cheer()` without defining it","d":"put the call before the indented body"}}},"tryIt":{"try_defining_and_calling_functions_checkpoint":{"title":"Try it yourself","prompt":"Define `say_hello()` so it prints `Hello from a function!`, then call it."},"try_defining_and_calling_functions_sketch0":{"title":"Try it yourself","prompt":"Define a no-argument function, put its work in the indented body, and call it once."},"try_defining_and_calling_functions_sketch1":{"title":"Try it yourself","prompt":"Reuse one already-defined function by calling it exactly three times."},"try_defining_and_calling_functions_sketch2":{"title":"Try it yourself","prompt":"Define a no-argument function named `show_colors()`. Inside it, create a list named `colors` containing `red`, `blue`, and `green` in that order, loop through `colors`, and print each color. After the definition, call `show_colors()` once."},"allowReveal":true}},"docstrings-and-function-contracts":{"label":"Docstrings and Function Contracts","summary":"Write real function docstrings as the first statement in a function, use them to describe inputs and returned results, and keep implementation behavior consistent with the documented contract.","cards":{"sketch0":{"title":"A docstring is the function's first statement"},"sketch1":{"title":"A contract explains inputs and returned results"},"sketch2":{"title":"The implementation must match the contract"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-docstring-location":{"title":"Where a docstring goes","prompt":"Where should a function's docstring be placed?","hint":"Look for the string that appears immediately inside the function.","help":{"concept":"A function docstring is the first string literal inside the function body, directly under the `def` line.","hint_1":"It is not placed before the function definition or after the return statement.","hint_2":"Choose the option where the triple-quoted string comes right after `def ...:`."},"options":{"a":"Directly under the function definition as the first statement","b":"Inside the parameter list","c":"After the return statement","d":"Only at the end of the program"}},"sc-contract-purpose":{"title":"What a function contract explains","prompt":"What is the main purpose of a function contract?","hint":"Think about inputs and outputs.","help":{"concept":"A function contract tells other programmers what values a function expects and what result or behavior it provides.","hint_1":"A contract is about how to use the function correctly, not about changing Python syntax.","hint_2":"Pick the option that mentions expected arguments and returned result."},"options":{"a":"It explains what inputs the function expects and what it returns","b":"It automatically fixes bugs in the function","c":"It makes the function run faster","d":"It replaces the need for function names"}},"mc-good-docstring-features":{"title":"Features of a helpful docstring","prompt":"Which statements describe a helpful function docstring? Choose all that apply.","hint":"Look for statements that make the function easier to use correctly.","help":{"concept":"Helpful docstrings are specific, match the code, and explain the function's behavior clearly enough for someone to call it correctly.","hint_1":"Good docstrings usually mention what the function returns or does with its inputs.","hint_2":"Select the choices that are clear and accurate, not vague or unrelated."},"options":{"a":"It clearly says what the function returns or does","b":"It matches the actual behavior of the code","c":"It should be as vague as possible so it works for any function","d":"It can mention important input expectations"}},"mc-return-vs-print-contract":{"title":"Return vs print in a contract","prompt":"A docstring says a function returns a value. Which code patterns fit that contract? Choose all that apply.","hint":"Look for functions that send a value back to the caller.","help":{"concept":"When a contract says a function returns a value, the function should use `return` so the caller can store or reuse the result.","hint_1":"Printing shows output, but it does not give the caller a reusable value.","hint_2":"Choose the options that use `return` to produce the result."},"options":{"a":"`return a + b`","b":"`return name.upper()`","c":"`print(a + b)`","d":"`print(\"Done\")`"}},"dr-docstring-order":{"title":"Order of a documented function","prompt":"Put these parts in the correct order for a simple documented function.","hint":"Start with the function header, then the docstring, then the body.","help":{"concept":"A documented function is written in a standard order: definition line first, docstring next, then the executable code.","hint_1":"The docstring belongs inside the function, not before the `def` line.","hint_2":"After the docstring, place the statement that computes or returns the result."},"tokens":{"t1":"`def double(number):`","t2":"`\"\"\"Return twice number.\"\"\"`","t3":"`return number * 2`"}},"dr-contract-reading":{"title":"Read a function contract in order","prompt":"Arrange these ideas in a sensible order for understanding a function contract.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"Inputs the function expects","t2":"What the function does","t3":"Value the function returns"}},"fb-return-word":{"title":"Complete the docstring wording","prompt":"Choose the word that best completes the docstring.","hint":"The sentence describes giving a value back to the caller.","help":{"concept":"A docstring should describe the value sent back to the caller when the function does not merely print.","hint_1":"Choose the verb used in function documentation for a value sent back to the caller.","hint_2":"Pick the choice that means the function gives a result back to the caller."},"template":"`\"\"\"[blank1] the sum of two numbers.\"\"\"`","choices":["Return","Print","Loop through","Import"]},"fb-docstring-position":{"title":"Complete the function example","prompt":"Choose the line that correctly fills the blank.","hint":"The missing line should be the docstring, not code that runs the calculation.","help":{"concept":"The docstring is a descriptive string placed as the first statement inside the function body.","hint_1":"The blank comes right after the function header.","hint_2":"Choose the triple-quoted string that describes the function's result."},"template":"```python\ndef square(number):\n [blank1]\n return number * number\n```","choices":["`\"\"\"Return the square of number.\"\"\"`","`print(number * number)`","`number * number`","`square(number)`"]},"ci-add-docstring":{"title":"Add a matching docstring","prompt":"Add a docstring under `make_lower(text)` that clearly says what the function returns.","hint":"Read the task \"Add a matching docstring\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_lower(text):\n # Add a docstring below.\n return text.lower()","solutionCode":"def make_lower(text):\n \"\"\"Return the lowercase version of text.\"\"\"\n return text.lower()"},"ci-write-contract-function":{"title":"Write a documented function with a clear contract","prompt":"Write `repeat_word(word, times)` so it returns the repeated text, and add a docstring that explains that contract clearly.","hint":"Read the task \"Write a documented function with a clear contract\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def repeat_word(word, times):\n # Add a docstring and return the repeated word.\n pass","solutionCode":"def repeat_word(word, times):\n \"\"\"Return word repeated times times.\"\"\"\n return word * times"},"ci-fix-print-vs-return":{"title":"Fix the contract mismatch","prompt":"The docstring says `total_price(price, tax)` should return the total, but the starter code prints it instead. Fix the function so its behavior matches the docstring.","hint":"Read the task \"Fix the contract mismatch\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def total_price(price, tax):\n \"\"\"Return the total of price and tax.\"\"\"\n print(price + tax)","solutionCode":"def total_price(price, tax):\n \"\"\"Return the total of price and tax.\"\"\"\n return price + tax"},"try-docstrings-and-function-contracts-checkpoint":{"title":"Write a documented helper","prompt":"Define `square(number)` with a docstring and return the square of the number. Print `square(5)`.","hint":"Place a triple-quoted string as the first line inside the function.","help":{"concept":"A docstring describes the function contract for readers and tools.","hint_1":"Place a triple-quoted string as the first line inside the function.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def square(number):\n # Add a docstring and return the square.\n pass\n\nprint(square(5))\n","solutionCode":"def square(number):\n \"\"\"Return number multiplied by itself.\"\"\"\n return number * number\n\nprint(square(5))\n"},"try-docstrings-and-function-contracts-sketch0":{"title":"Add a real docstring to a working function","prompt":"The function already works. Add the docstring `\"\"\"Return text stripped and title-cased.\"\"\"` as the first statement inside `normalize_city(text)`. Do not change the function's behavior.","hint":"Place the triple-quoted string directly under `def normalize_city(text):`, before the return statement.","help":{"concept":"A real function docstring is the first string literal in the function body.","hint_1":"Do not turn the requested docstring into a `#` comment.","hint_2":"Keep the existing `return text.strip().title()` behavior unchanged."},"starterCode":"def normalize_city(text):\n return text.strip().title()\n\ncity = input()\nprint(normalize_city(city))\n","solutionCode":"def normalize_city(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n\ncity = input()\nprint(normalize_city(city))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-docstrings-and-function-contracts-sketch1":{"title":"Fix code that breaks its return contract","prompt":"`total_price(price, tax)` already has the contract `\"\"\"Return price plus tax.\"\"\"`, but the implementation prints the total instead of returning it. Fix the function so the caller receives the value. Keep the existing docstring.","hint":"Replace the display-only behavior inside the function with a return statement.","help":{"concept":"If a contract promises a returned value, the implementation must give that value back to the caller.","hint_1":"Inside the function, use `return price + tax`.","hint_2":"Do not replace or remove the existing docstring."},"starterCode":"def total_price(price, tax):\n \"\"\"Return price plus tax.\"\"\"\n print(price + tax)\n\nprice = int(input())\ntax = int(input())\nresult = total_price(price, tax)\nprint(result)\n","solutionCode":"def total_price(price, tax):\n \"\"\"Return price plus tax.\"\"\"\n return price + tax\n\nprice = int(input())\ntax = int(input())\nresult = total_price(price, tax)\nprint(result)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-docstrings-and-function-contracts-sketch2":{"title":"Implement a function from its contract","prompt":"`is_passing(score)` already documents its contract: `\"\"\"Return True when score is 70 or higher.\"\"\"`. Complete the function so its returned Boolean value matches that contract for every score.","hint":"The phrase '70 or higher' translates to a greater-than-or-equal comparison.","help":{"concept":"A contract can be read as a precise requirement for the implementation.","hint_1":"Return a Boolean expression rather than printing a message.","hint_2":"Use `return score >= 70` so 70 itself is included."},"starterCode":"def is_passing(score):\n \"\"\"Return True when score is 70 or higher.\"\"\"\n pass\n\nscore = int(input())\nprint(is_passing(score))\n","solutionCode":"def is_passing(score):\n \"\"\"Return True when score is 70 or higher.\"\"\"\n return score >= 70\n\nscore = int(input())\nprint(is_passing(score))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"sc-real-docstring":{"title":"Identify a real function docstring","prompt":"Which placement makes a string the docstring for `clean(text)`?","hint":"Python recognizes the first string literal in the function body as its docstring.","help":{"concept":"A function docstring is a string literal used as the first statement inside that function.","hint_1":"A comment does not become the function's docstring.","hint_2":"The triple-quoted string belongs directly under the `def` line, before executable statements."},"options":{"a":"def clean(text):\n \"\"\"Return cleaned text.\"\"\"\n return text.strip()","b":"\"\"\"Return cleaned text.\"\"\"\ndef clean(text):\n return text.strip()","c":"def clean(text):\n return text.strip()\n \"\"\"Return cleaned text.\"\"\"","d":"def clean(text):\n # \"\"\"Return cleaned text.\"\"\"\n return text.strip()"}},"sc-contract-content":{"title":"What a useful contract explains","prompt":"Which docstring most clearly describes the contract of `double(number)`?","hint":"A useful beginner contract says what input the function works with and what result comes back.","help":{"concept":"A clear contract describes the function's expected input and the result or behavior it provides.","hint_1":"Avoid vague wording such as 'Do something with a number.'","hint_2":"The best choice states that the function returns twice the given number."},"options":{"a":"\"\"\"Return twice the given number.\"\"\"","b":"\"\"\"Do something.\"\"\"","c":"\"\"\"This is Python code.\"\"\"","d":"\"\"\"Print anything eventually.\"\"\""}},"sc-contract-match":{"title":"Match code to the contract","prompt":"The docstring says `\"\"\"Return the uppercase version of text.\"\"\"`. Which function body matches that contract?","hint":"The caller must receive the uppercase string as a value.","help":{"concept":"Documentation is useful only when it agrees with the implementation.","hint_1":"The contract says `Return`, so printing alone is not enough.","hint_2":"Return `text.upper()`."},"options":{"a":"return text.upper()","b":"print(text.upper())","c":"input(text.upper())","d":"text = \"upper\""}},"sc-read-contract":{"title":"Implement from a stated contract","prompt":"A function's docstring says `\"\"\"Return True when score is 70 or higher.\"\"\"`. Which expression should the function return?","hint":"Translate the documented condition directly into a Boolean expression.","help":{"concept":"A contract can guide implementation by stating exactly what result is expected.","hint_1":"The boundary value 70 should count as True.","hint_2":"Use a greater-than-or-equal comparison."},"options":{"a":"score >= 70","b":"score > 70","c":"score == 70","d":"print(score)"}}},"tryIt":{"try_docstrings_and_function_contracts_checkpoint":{"title":"Try it yourself","prompt":"Define `square(number)` with a docstring and return the square of the number. Print `square(5)`."},"try_docstrings_and_function_contracts_sketch0":{"title":"Try it yourself","prompt":"Add a real function docstring without changing already-correct behavior."},"try_docstrings_and_function_contracts_sketch1":{"title":"Try it yourself","prompt":"Fix an implementation that prints even though its documented contract promises a returned value."},"try_docstrings_and_function_contracts_sketch2":{"title":"Try it yourself","prompt":"Read an existing function contract and implement the exact behavior it describes."},"allowReveal":true}},"module-6-name-badge-package":{"label":"Module Project: Build a Name Badge App","summary":"Refactor a working single-file badge program into focused sibling modules, document the helper contracts, and connect the returned values into one polished welcome message.","cards":{"sketch0":{"title":"Start from one working badge program"},"project":{"title":"Name Badge App"}},"projectSteps":{"mp_1":{"title":"Move name cleanup into names.py"},"mp_2":{"title":"Move badge formatting into badges.py"},"mp_3":{"title":"Document and refine the helper contracts"},"mp_4":{"title":"Add the final welcome-message helper"}},"quiz":{"mp-1-create-clean-name-module":{"title":"Create the name cleaner module","prompt":"Start the badge app by moving name cleanup into its own helper file. Create `tools/names.py` with `clean_name(text)`, import it in `main.py`, read one name from input, and print the cleaned result.","hint":"Put the reusable cleaning logic in `tools/names.py`, then let `main.py` call it.","help":{"concept":"A helper module keeps reusable logic out of `main.py`, which makes the badge app easier to grow.","hint_1":"In `tools/names.py`, define `clean_name(text)` and return `text.strip().title()`.","hint_2":"In `main.py`, import `clean_name`, read input, and print the cleaned name."},"starterCode":"raw_name = input()\n\n# Start the badge app by moving name cleanup into tools/names.py.\n# Import clean_name, then print the cleaned version of raw_name.\n","solutionFiles":{"main_py":{"content":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Import from tools.names."},"1":{"message":"Define clean_name(text) inside tools/names.py."},"2":{"message":"clean_name should strip whitespace."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"mp-2-add-badge-helper":{"title":"Add the badge helper module","prompt":"Keep the working `clean_name` helper from the last step. Now add `tools/badges.py` with `make_badge(name, role)`, import it in `main.py`, read a role too, and print the finished badge.","hint":"Leave `tools/names.py` working, add one new helper file, then connect it in `main.py`.","help":{"concept":"This step adds a second helper file so each module has one clear job: names clean names, badges format badge text.","hint_1":"Create `tools/badges.py` with `make_badge(name, role)`.","hint_2":"In `main.py`, clean the name first, then pass `name` and `role` into `make_badge(...)`."},"starterCode":"from tools.names import clean_name\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\n\n# Keep the name cleaner working, then add tools.badges.\n# Import make_badge and print the finished badge for this cleaned name and role.\n","starterFiles":{"tools_init_py":{"content":""},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"# Add make_badge(name, role) here.\n# Return one formatted string for the badge.\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Import from tools.badges."},"1":{"message":"Define make_badge in tools/badges.py."},"2":{"message":"make_badge should uppercase the role."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"mp-3-document-badge-helper":{"title":"Document and clean the badge helper","prompt":"Start from the working two-helper badge app. Keep the output the same, but improve `tools/badges.py` by adding a docstring and cleaning the role before uppercasing it.","hint":"This step refines the helper in place instead of changing the overall app flow.","help":{"concept":"Small helper functions are easier to maintain when they explain themselves and handle messy input cleanly.","hint_1":"Add a triple-quoted docstring under `def make_badge(name, role):`.","hint_2":"Store `role.strip().upper()` in a variable before returning the badge text."},"starterCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n\n# Keep this badge flow working.\n# Add the next improvement inside tools/badges.py.\n","starterFiles":{"tools_init_py":{"content":""},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n # Add a docstring that explains what this helper returns.\n # Then clean role before uppercasing it so extra spaces do not reach the badge.\n return f\"{role.upper()} badge: {name}\"\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return a formatted badge label for a cleaned name and role.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Add a docstring to make_badge in tools/badges.py."},"1":{"message":"Clean the role before uppercasing it."},"2":{"message":"Uppercase the role in make_badge."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"mp-4-package-welcome-message":{"title":"Print the final welcome badge","prompt":"Start from the documented badge app. Keep both helpers, store the badge in a variable, and replace the direct badge print with one friendly final line that begins with `Welcome!`.","hint":"Reuse the existing helper flow, but make the final output feel like a polished handoff.","help":{"concept":"The final app uses small helper modules to make the main program read like a simple story: get input, clean it, build the badge, print the welcome message.","hint_1":"Use `badge = make_badge(name, role)` after cleaning the name.","hint_2":"Print one line that starts with `Welcome!` and includes the badge text."},"starterCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n\n# Replace the line above with one polished welcome message.\n# Store the badge in a variable, then print a line that starts with Welcome!.\n","starterFiles":{"tools_init_py":{"content":""},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return a formatted badge label for a cleaned name and role.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(f\"Welcome! {badge}\")\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return a formatted badge label for a cleaned name and role.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Build the badge with make_badge() instead of hard-coding the final text."},"1":{"message":"Print the final welcome message."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(f\"Welcome! {badge}\")\n"},"try-module-6-name-badge-package-sketch0":{"title":"Complete the single-file badge starting point","prompt":"Complete `clean_name(text)` so the starting badge program works in one file. Return the name with surrounding spaces removed and title-cased. Do not move functions into helper files yet—the project steps will refactor this working version.","hint":"Return `text.strip().title()` from `clean_name`.","help":{"concept":"The project begins with working single-file behavior so later steps can focus on refactoring structure without losing correctness.","hint_1":"Replace `pass` with `return text.strip().title()`.","hint_2":"Keep `make_badge`, input handling, and the final print unchanged."},"starterCode":"def clean_name(text):\n # Return text stripped and title-cased.\n pass\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Define clean_name in tools/names.py."},"2":{"message":"clean_name should strip spaces."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"def clean_name(text):\n # Return text stripped and title-cased.\n pass\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"}}},"mp-1-move-name-helper":{"title":"Move name cleanup into names.py","prompt":"Start from the working single-file badge program. Refactor it without changing the output: move `clean_name(text)` into a new sibling file named `names.py`, then import it in `main.py` with a from-import that brings `clean_name` in from the `names` module. Keep `make_badge` in `main.py` for this step.","hint":"Only the name-cleaning responsibility moves in this step.","help":{"concept":"A refactor can move one helper into its own module while preserving the app's existing behavior.","hint_1":"Create `names.py` with the existing `clean_name(text)` function.","hint_2":"Remove that function definition from `main.py` and import it from `names`."},"starterCode":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"def clean_name(text):\n return text.strip().title()\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"}},"solutionCode":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `clean_name` from `names`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"mp-2-move-badge-helper":{"title":"Move badge formatting into badges.py","prompt":"Continue from the previous exact project state. Move `make_badge(name, role)` out of `main.py` into a new sibling file `badges.py`, import it with a from-import that brings `make_badge` in from the `badges` module, and keep the same badge output.","hint":"After this step, `main.py` should coordinate the two imported helpers instead of defining either one.","help":{"concept":"Different sibling modules can own different responsibilities while `main.py` connects their returned values.","hint_1":"Create `badges.py` and move the existing `make_badge` behavior there.","hint_2":"Import both `clean_name` and `make_badge` in `main.py`."},"starterCode":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"from names import clean_name\n\ndef make_badge(name, role):\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.strip().upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `make_badge` from `badges`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Call `make_badge(...)` because that function call is explicitly required by the prompt."}}},"mp-3-document-helper-contracts":{"title":"Document and refine the helper contracts","prompt":"Keep the two-module badge app behavior unchanged. Add the exact docstring `\"\"\"Return text stripped and title-cased.\"\"\"` as the first statement in `clean_name`. Add the exact docstring `\"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"` as the first statement in `make_badge`. In `make_badge`, store `role.strip().upper()` in local variable `clean_role` before returning the badge.","hint":"This step changes documentation and internal structure, not the app's output.","help":{"concept":"A documented helper should have a real function docstring that matches its behavior, and local variables can make intermediate work clearer.","hint_1":"Put each requested triple-quoted string directly under its `def` line.","hint_2":"In `badges.py`, create `clean_role = role.strip().upper()` and build the returned badge from `clean_role`."},"starterCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.strip().upper()} badge: {name}\"\n"}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Use `upper()` because that method is explicitly required by the prompt."}}},"mp-4-add-welcome-helper":{"title":"Add the final welcome-message helper","prompt":"Continue from the documented two-helper app. Create a sibling module `messages.py` with `welcome_message(badge)`. Give it the docstring `\"\"\"Return a welcome message containing the badge.\"\"\"` and return `\"Welcome! \" + badge`. Import it in `main.py` and print the returned welcome message.","hint":"The new helper owns only the final message; keep name cleanup and badge formatting in their existing modules.","help":{"concept":"The finished app decomposes three responsibilities across three small sibling modules while `main.py` coordinates their returned values.","hint_1":"Create `messages.py` with a documented `welcome_message(badge)` function.","hint_2":"Import it with `from messages import welcome_message` and print `welcome_message(badge)`."},"starterCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n","starterFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(badge)\n"},"names_py":{"content":"def clean_name(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\nfrom messages import welcome_message\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(welcome_message(badge))\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\nfrom messages import welcome_message\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(welcome_message(badge))\n"},"names_py":{"content":"def clean_name(text):\n \"\"\"Return text stripped and title-cased.\"\"\"\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n \"\"\"Return an uppercase-role badge for the cleaned name.\"\"\"\n clean_role = role.strip().upper()\n return f\"{clean_role} badge: {name}\"\n"},"messages_py":{"content":"def welcome_message(badge):\n \"\"\"Return a welcome message containing the badge.\"\"\"\n return \"Welcome! \" + badge\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}}},"tryIt":{"try_module_6_name_badge_package_sketch0":{"title":"Try it yourself","prompt":"Complete the working single-file badge baseline that the project will refactor."},"allowReveal":true}},"parameters-and-return-values":{"label":"Parameters and Return Values","summary":"Use parameters to receive argument values, pass multiple arguments in the correct order, and return results that the caller can store or use.","cards":{"sketch0":{"title":"Parameters receive argument values"},"sketch1":{"title":"Functions can receive more than one parameter"},"quiz":{"title":"Check your understanding"},"sketch2":{"title":"Return sends a result back to the caller"}},"quiz":{"sc-parameter-role":{"title":"What a parameter does","prompt":"In `def greet(name):`, what is `name`?","hint":"Look at the value that gets passed into the function call.","help":{"concept":"A parameter is a variable in a function definition that receives a value when the function is called.","hint_1":"`name` appears inside the parentheses of the function definition, so it is part of the function's input.","hint_2":"Ask which choice describes a placeholder that gets its value from a call like `greet(\"Ava\")`."},"options":{"a":"A parameter that receives an argument value","b":"A printed output line","c":"A list method","d":"A return statement"}},"sc-return-purpose":{"title":"Why use return","prompt":"What does `return` do in a Python function?","hint":"Think about how a function sends a result back to the code that called it.","help":{"concept":"The `return` statement ends the function call and gives a value back to the caller.","hint_1":"Unlike `print`, `return` does not mainly display text in the output panel.","hint_2":"Choose the option about sending a result out of the function so it can be stored or used later."},"options":{"a":"It repeats the function automatically","b":"It sends a value back to the caller","c":"It creates a new parameter","d":"It renames the function"}},"mc-return-uses":{"title":"Ways to use a returned value","prompt":"Which statements correctly use a function's returned value? Choose all that apply.","hint":"A returned value can be stored, printed, or used inside another expression.","help":{"concept":"Returned values behave like regular values, so they can be assigned, printed, or combined in expressions.","hint_1":"Look for lines where the function call appears where a normal value could appear.","hint_2":"A function call that returns a number can go on the right side of `=` or inside `print(...)`."},"options":{"a":"`total = add(2, 3)`","b":"`print(add(2, 3))`","c":"`return = add(2, 3)`","d":"`def add = (2, 3)`"}},"mc-print-vs-return":{"title":"Print versus return","prompt":"Which statements about `print` and `return` are true? Choose all that apply.","hint":"One shows output now, and the other gives a value back to the caller.","help":{"concept":"`print` displays text in the output panel, while `return` passes a value back from the function.","hint_1":"Think about whether the result can be reused later in another variable or expression.","hint_2":"Choose the statements that match these roles: visible output for `print`, reusable result for `return`."},"options":{"a":"`print` sends visible text to the output panel","b":"`return` can give a result back to the caller","c":"`print` and `return` always do exactly the same job","d":"`return` can only be used outside functions"}},"dr-function-flow":{"title":"Order of a function call","prompt":"Put these steps in the correct order for what happens when a function with parameters is called.","hint":"Start with the call, then think about values entering the function and a result coming back.","help":{"concept":"A function call follows a sequence: call the function, pass arguments into parameters, run the body, then return a result.","hint_1":"The function body cannot run until the arguments have been matched to the parameters.","hint_2":"The returned value comes after the body finishes its calculation."},"tokens":{"t1":"Call the function with argument values","t2":"Those values are assigned to the parameters","t3":"The function body runs using those parameter values","t4":"The function returns a result to the caller"}},"dr-build-function":{"title":"Build a simple return function","prompt":"Arrange these lines to make a function that takes one parameter and returns double the value.","hint":"The function header comes first, then the return line, then the call that uses the result.","help":{"concept":"A basic function definition needs a header, an indented body, and then any code that calls the function.","hint_1":"The `return` line must be inside the function, so it belongs directly under the `def` line.","hint_2":"The line that prints the result should come after the function has been defined."},"tokens":{"t1":"def double(number):","t2":"return number * 2","t3":"result = double(5)","t4":"print(result)"}},"fb-call-argument":{"title":"Fill the argument","prompt":"Complete the function call so the function receives the number 7.","hint":"The blank is the value being passed into the function call.","help":{"concept":"An argument is the actual value you place inside the parentheses when calling a function.","hint_1":"The function name is already written, so the missing part is the value inside the parentheses.","hint_2":"Choose the number that would be passed into `show_score` as its input."},"template":"show_score([blank1])","choices":["show_score","7","return"]},"fb-return-expression":{"title":"Complete the return line","prompt":"Choose the expression that makes the function return the sum of `price` and `tax`.","hint":"The blank should be the value expression after `return`.","help":{"concept":"A return statement can send back the result of an expression, such as adding two parameters together.","hint_1":"Both `price` and `tax` are already available as parameter names in the function.","hint_2":"Pick the choice that adds the two parameter values instead of naming a keyword or only one variable."},"template":"return [blank1]","choices":["price + tax","def","price"]},"ci-make-label":{"title":"Return a label string","prompt":"Write `make_label(item, count)` so it returns a label string like `Apples: 3`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_label(item, count):\n # return a string like \"Apples: 3\"\n pass","solutionCode":"def make_label(item, count):\n return item + \": \" + str(count)"},"ci-calculate-tip":{"title":"Return a tip amount","prompt":"Write `calculate_tip(bill, percent)` so it returns just the tip amount for that bill and percent.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def calculate_tip(bill, percent):\n # return the tip amount\n pass","solutionCode":"def calculate_tip(bill, percent):\n return bill * percent / 100"},"ci-first-item":{"title":"Return the first list item","prompt":"Write `first_item(items)` so it returns the first element from the list.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def first_item(items):\n # return the first element from the list\n pass","solutionCode":"def first_item(items):\n return items[0]"},"try-parameters-and-return-values-checkpoint":{"title":"Return a doubled number","prompt":"Define `double(number)` so it returns twice the input. Print `double(7)`.","hint":"Use `return number * 2`.","help":{"concept":"A return value sends a result back to the caller.","hint_1":"Use `return number * 2`.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def double(number):\n # Return twice the number.\n pass\n\nprint(double(7))\n","solutionCode":"def double(number):\n return number * 2\n\nprint(double(7))\n"},"try-parameters-and-return-values-sketch0":{"title":"Reuse one parameter with different arguments","prompt":"Complete `make_badge(name)` so it returns `Badge: ` followed by `name`. The program reads two names. Keep the two calls so the same function produces one badge for each input name.","hint":"The parameter `name` receives a different argument on each call.","help":{"concept":"One parameter lets the same function body work with different argument values.","hint_1":"Inside the function, return `\"Badge: \" + name`.","hint_2":"Leave the calls `make_badge(name1)` and `make_badge(name2)` in place."},"starterCode":"def make_badge(name):\n # Return \"Badge: \" followed by name.\n pass\n\nname1 = input()\nname2 = input()\nprint(make_badge(name1))\nprint(make_badge(name2))\n","solutionCode":"def make_badge(name):\n return \"Badge: \" + name\n\nname1 = input()\nname2 = input()\nprint(make_badge(name1))\nprint(make_badge(name2))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `make_badge(...)` because that function call is explicitly required by the prompt."}}},"try-parameters-and-return-values-sketch1":{"title":"Use two parameters in order","prompt":"Complete `difference(high, low)` so it returns `high - low`. The program reads two integers and prints the value returned by `difference(high, low)`.","hint":"The first argument becomes `high`; the second becomes `low`.","help":{"concept":"With multiple positional parameters, argument order determines which value each parameter receives.","hint_1":"Return `high - low` inside the function.","hint_2":"Keep the call in the same order: `difference(high, low)`."},"starterCode":"def difference(high, low):\n # Return high minus low.\n pass\n\nhigh = int(input())\nlow = int(input())\nprint(difference(high, low))\n","solutionCode":"def difference(high, low):\n return high - low\n\nhigh = int(input())\nlow = int(input())\nprint(difference(high, low))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `difference(...)` because that function call is explicitly required by the prompt."}}},"sc-parameter-vs-argument":{"title":"Parameter versus argument","prompt":"Given `def greet(name):` and the call `greet(\"Ava\")`, which statement is correct?","hint":"Look separately at the function definition and the function call.","help":{"concept":"A parameter is the variable named in the definition; an argument is the actual value supplied by a call.","hint_1":"`name` is written in `def greet(name):`, so it is the parameter.","hint_2":"`\"Ava\"` is supplied by `greet(\"Ava\")`, so it is the argument."},"options":{"a":"`name` is the parameter and `\"Ava\"` is the argument","b":"`\"Ava\"` is the parameter and `name` is the argument","c":"Both are return values","d":"Neither one provides input to the function"}},"sc-argument-order":{"title":"Match arguments to parameters","prompt":"Given `def subtract(first, second): return first - second`, what does `subtract(10, 3)` return?","hint":"The first argument goes into `first`; the second argument goes into `second`.","help":{"concept":"Positional arguments are matched to parameters from left to right.","hint_1":"For this call, `first` becomes `10`.","hint_2":"`second` becomes `3`, so evaluate `10 - 3`."},"options":{"a":"7","b":"-7","c":"13","d":"3"}},"sc-valid-two-argument-call":{"title":"Call a two-parameter function","prompt":"A function is defined as `def show_pair(left, right):`. Which call supplies both required arguments?","hint":"There are two parameters, so the call needs two argument values.","help":{"concept":"A normal call must supply the required number of positional arguments.","hint_1":"Look for two comma-separated values inside the parentheses.","hint_2":"The function name in the call must still be `show_pair`."},"options":{"a":"show_pair()","b":"show_pair(\"A\")","c":"show_pair(\"A\", \"B\")","d":"def show_pair(\"A\", \"B\")"}},"sc-returned-value":{"title":"Use a returned value","prompt":"If `double(5)` returns `10`, what value is stored by `result = double(5)`?","hint":"The returned value replaces the function call in the assignment.","help":{"concept":"A returned value can be assigned to a variable just like another computed value.","hint_1":"`double(5)` produces the value `10`.","hint_2":"That value is assigned to `result`."},"options":{"a":"5","b":"10","c":"double","d":"Nothing is stored"}},"try-parameters-and-return-values-sketch2":{"title":"Store a returned result","prompt":"Complete `rectangle_area(width, height)` so it returns `width * height`. Then keep the caller code that stores the returned value in `area` and prints `area`.","hint":"The function should return the calculation; the assignment outside the function stores that returned value.","help":{"concept":"A return value travels back to the call site, where it can be assigned to a variable and used later.","hint_1":"Inside the function, write `return width * height`.","hint_2":"Outside the function, `area = rectangle_area(width, height)` stores the returned number."},"starterCode":"def rectangle_area(width, height):\n # Return the rectangle's area.\n pass\n\nwidth = int(input())\nheight = int(input())\narea = rectangle_area(width, height)\nprint(area)\n","solutionCode":"def rectangle_area(width, height):\n return width * height\n\nwidth = int(input())\nheight = int(input())\narea = rectangle_area(width, height)\nprint(area)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `rectangle_area(...)` because that function call is explicitly required by the prompt."}}}},"tryIt":{"try_parameters_and_return_values_checkpoint":{"title":"Try it yourself","prompt":"Define `double(number)` so it returns twice the input. Print `double(7)`."},"try_parameters_and_return_values_sketch0":{"title":"Try it yourself","prompt":"Use one parameter with two different argument values and return a result for each call."},"try_parameters_and_return_values_sketch1":{"title":"Try it yourself","prompt":"Use two parameters in order and return a calculation based on both values."},"allowReveal":true,"try_parameters_and_return_values_sketch2":{"title":"Try it yourself","prompt":"Return a computed result and store that returned value in a caller-side variable."}}},"print-vs-return":{"label":"Print vs Return","summary":"Distinguish display-only functions from functions that return reusable data, understand why printing a print-only call shows `None`, and fix code that prints when the caller needs a value.","cards":{"sketch0":{"title":"Printing displays a value but returns None"},"sketch1":{"title":"Returned values can be stored and reused"},"sketch2":{"title":"Fix a function that prints when it should return"},"quiz":{"title":"Check your understanding"}},"quiz":{"pvrs-sc-1":{"title":"Which statement describes return?","prompt":"Which statement best describes what `return` does in a function?","hint":"Think about whether the value is only shown or sent back to the code that called the function.","help":{"concept":"`return` gives a result back to the caller so it can be stored, reused, or combined with other values.","hint_1":"A returned value can be assigned to a variable like `result = my_function()`.","hint_2":"Look for the option about sending a value back from the function, not just displaying it."},"options":{"a":"It sends a value back from the function to the caller.","b":"It always prints a value in the output panel.","c":"It repeats the function from the beginning.","d":"It creates a new parameter automatically."}},"pvrs-sc-2":{"title":"Which function result can be reused?","prompt":"A function should calculate a number and let later code multiply that number by 10. Which approach is best?","hint":"The later code needs the function's result as a value, not just visible output.","help":{"concept":"When later code must keep using a result, the function should return that result instead of only printing it.","hint_1":"If the function only prints, another expression cannot directly use that printed value in a calculation.","hint_2":"Choose the option where the function gives the number back so another line can store it and multiply it."},"options":{"a":"Use `return` inside the function and store the result in a variable.","b":"Use `print()` inside the function and assume later code can multiply the printed text.","c":"Add more parameters until the function becomes reusable.","d":"Put the multiplication inside the function even if other code needs the original result."}},"pvrs-mc-1":{"title":"Choose the true statements","prompt":"Which statements about `print()` and `return` are true? Choose all that apply.","hint":"Separate what the user sees in the output panel from what the rest of the program can keep using.","help":{"concept":"`print()` is for display, while `return` is for producing a value that calling code can use.","hint_1":"A returned value can be assigned to a variable; printed output is just displayed.","hint_2":"Pick the options that describe display versus reusable results correctly."},"options":{"a":"`print()` displays output for the user to see.","b":"`return` can send a value back to the code that called the function.","c":"A function can never use both `print()` and `return`.","d":"If a function only prints a value, that printed value is automatically stored in a variable."}},"pvrs-mc-2":{"title":"Ways to use a returned value","prompt":"A function `make_label(name)` returns a string. Which lines use that returned value correctly? Choose all that apply.","hint":"Look for lines where the function call becomes part of another expression or is stored for later use.","help":{"concept":"A returned value behaves like any other value, so it can be stored, printed, or combined with other strings.","hint_1":"If the function returns text, valid uses include assignment and string concatenation.","hint_2":"Choose the lines where the function call is treated like a string value produced by the function."},"options":{"a":"`label = make_label(\"Mia\")`","b":"`print(make_label(\"Mia\"))`","c":"`message = make_label(\"Mia\") + \"!\"`","d":"`return = make_label(\"Mia\")`"}},"pvrs-dr-1":{"title":"Order the return flow","prompt":"Put these steps in the correct order for code that returns a value and then prints it.","hint":"Start with the function call, then think about what the function sends back, then what gets displayed.","help":{"concept":"When a function returns a value, the call runs first, the value comes back to the caller, it can be stored, and then it may be printed.","hint_1":"The function must run before a variable can receive its returned value.","hint_2":"The displayed output happens after the returned value has already come back and been used by the calling code."},"tokens":{"t1":"Call the function.","t2":"The function computes a result.","t3":"The function returns the value.","t4":"The caller stores or uses that value.","t5":"`print()` can display it."}},"pvrs-dr-2":{"title":"Build a reusable pattern","prompt":"Arrange these code pieces into a sensible pattern for using a returned value.","hint":"First define the function, then call it, then store the result, then display or reuse it.","help":{"concept":"A common pattern is define a function with `return`, call it, save the returned value, and then use that value later.","hint_1":"The function definition must come before the call that uses it.","hint_2":"After the call returns a value, that value should be assigned before a later `print()` uses the variable."},"tokens":{"t1":"`def add_one(n):`","t2":"` return n + 1`","t3":"`result = add_one(4)`","t4":"`print(result)`"}},"pvrs-fb-1":{"title":"Complete the keyword","prompt":"Choose the word that correctly completes the function so it sends a value back.","hint":"The missing word should give the result back to the caller.","help":{"concept":"A function uses a dedicated statement to send a computed value back to its caller.","hint_1":"`print` shows output, but this blank needs the keyword that hands the value back.","hint_2":"Choose the Python keyword used before an expression like `n * 2` when a function should produce a reusable result."},"template":"def double(n):\n [blank1] n * 2","choices":["print","return","input","def"]},"pvrs-fb-2":{"title":"Complete the display line","prompt":"Choose the code that displays the returned value from `get_name()` in the output panel.","hint":"The function already returns the value, so the missing part should show that value.","help":{"concept":"If a function returns a value and you want to display it, wrap the function call in `print()`.","hint_1":"The blank is not inside the function definition; it is the line that shows the returned result.","hint_2":"Choose the option that calls the function and sends its result to the output panel."},"template":"[blank1]","choices":["print(get_name())","return get_name()","def get_name()","get_name = print()"]},"pvrs-code-1":{"title":"Return a doubled value","prompt":"Write `double_number(n)` so it returns double the input instead of printing it.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def double_number(n):\n # return double the input\n pass","solutionCode":"def double_number(n):\n return n * 2"},"pvrs-code-2":{"title":"Return a greeting string","prompt":"Write `make_greeting(name)` so it returns a greeting string like `Hello, Ava`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_greeting(name):\n # return a greeting like Hello, Ava\n pass","solutionCode":"def make_greeting(name):\n return \"Hello, \" + name"},"pvrs-code-3":{"title":"Return a total instead of printing it","prompt":"Write `add_prices(price1, price2)` so it returns the total of the two prices instead of printing it.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def add_prices(price1, price2):\n # return the total of the two prices\n pass","solutionCode":"def add_prices(price1, price2):\n return price1 + price2"},"try-print-vs-return-checkpoint":{"title":"Return, then print","prompt":"Define `add(a, b)` so it returns the sum. Then print `add(3, 4)`.","hint":"The function should return the value; the call site should print it.","help":{"concept":"Returning a value and printing a value are separate actions.","hint_1":"The function should return the value; the call site should print it.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def add(a, b):\n # Return the sum.\n pass\n\n# Print the result of add(3, 4).\n","solutionCode":"def add(a, b):\n return a + b\n\nprint(add(3, 4))\n"},"try-print-vs-return-sketch0":{"title":"Call a display-only function directly","prompt":"The starter defines `show_status(text)` as a display-only function: it prints the text and returns no value. The final line incorrectly wraps the call in `print(...)`, which would display an extra `None`. Change only the caller behavior so the status is displayed exactly once.","hint":"Because `show_status` already prints, call `show_status(status)` directly.","help":{"concept":"A display-only function should usually be called directly rather than wrapped in another `print()`.","hint_1":"Keep `print(text)` inside `show_status`.","hint_2":"Replace `print(show_status(status))` with a standalone `show_status(status)` call."},"starterCode":"def show_status(text):\n print(text)\n\nstatus = input()\nprint(show_status(status))\n","solutionCode":"def show_status(text):\n print(text)\n\nstatus = input()\nshow_status(status)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `show_status(...)` because that function call is explicitly required by the prompt."}}},"try-print-vs-return-sketch1":{"title":"Store and reuse a returned number","prompt":"The starter defines `double(number)` so it returns twice the number. Read the existing input into `number`, store `double(number)` in a variable named `result`, then print `result + 1`.","hint":"The returned number can be saved first and used in a later expression.","help":{"concept":"A returned value can be assigned to a variable and then reused in additional calculations.","hint_1":"Write `result = double(number)`.","hint_2":"Then print `result + 1`."},"starterCode":"def double(number):\n return number * 2\n\nnumber = int(input())\n# Store double(number) in result.\n# Then print result + 1.\n","solutionCode":"def double(number):\n return number * 2\n\nnumber = int(input())\nresult = double(number)\nprint(result + 1)\n","sourceChecks":{"0":{"message":"Call `double(...)` because that function call is explicitly required by the prompt."}}},"try-print-vs-return-sketch2":{"title":"Fix a function that prints instead of returning","prompt":"The starter's `make_label(item)` prints the label, but the caller needs to store that label and add `!`. Fix `make_label` so it returns `\"Item: \" + item` instead of printing it. Keep the caller-side assignment and final print.","hint":"The caller needs a string value in `label`, so the function must return the string.","help":{"concept":"Printing inside the function is not enough when the caller must store and transform the result.","hint_1":"Replace the function body's `print(...)` with `return \"Item: \" + item`.","hint_2":"Leave `label = make_label(item)` and `print(label + \"!\")` outside the function."},"starterCode":"def make_label(item):\n print(\"Item: \" + item)\n\nitem = input()\nlabel = make_label(item)\nprint(label + \"!\")\n","solutionCode":"def make_label(item):\n return \"Item: \" + item\n\nitem = input()\nlabel = make_label(item)\nprint(label + \"!\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `make_label(...)` because that function call is explicitly required by the prompt."}}},"sc-print-only-result":{"title":"What does the caller receive?","prompt":"A function contains `print(\"Ready\")` but no `return`. What value does the function call give back to its caller?","hint":"Visible output and a returned value are separate things.","help":{"concept":"A function with no explicit `return` gives the caller `None`, even if the function prints something.","hint_1":"`print(\"Ready\")` displays text in the output panel.","hint_2":"Because there is no `return`, the call itself evaluates to `None`."},"options":{"a":"\"Ready\"","b":"None","c":"print","d":"The function name"}},"sc-display-only-call":{"title":"Call a display-only function","prompt":"`show_status(text)` prints its text and does not return a value. Which line displays `Ready` once without also displaying `None`?","hint":"If the function already prints, call it directly.","help":{"concept":"Wrapping a display-only function call in another `print()` prints the function's implicit `None` result too.","hint_1":"`show_status(\"Ready\")` already causes the function body to print `Ready`.","hint_2":"Avoid `print(show_status(\"Ready\"))` when the function itself is responsible for display."},"options":{"a":"show_status(\"Ready\")","b":"print(show_status(\"Ready\"))","c":"return show_status(\"Ready\")","d":"show_status = \"Ready\""}},"sc-reuse-returned-value":{"title":"Reuse a function result","prompt":"`double(6)` returns `12`. Which code correctly stores that returned value and then uses it in another calculation?","hint":"Store the function call on the right side of an assignment.","help":{"concept":"A returned value behaves like another value: it can be assigned to a variable and used later.","hint_1":"First save `double(6)` in a variable.","hint_2":"Then use that variable in the later expression."},"options":{"a":"result = double(6)\nprint(result + 1)","b":"print = double(6)\nresult + 1","c":"double = 6\nprint(double + 1)","d":"return double(6)\nprint(result)"}},"sc-fix-print-return-bug":{"title":"Fix a print-versus-return bug","prompt":"The caller does `label = make_label(\"Book\")` and then needs `label + \"!\"`. Inside `make_label`, which statement should produce the label text?","hint":"The caller needs to receive a string value, not just see it displayed.","help":{"concept":"When later code must store or combine a function result, the function should return that result.","hint_1":"Printing the label would display it but leave `label` as `None`.","hint_2":"Return the string so the caller can concatenate `\"!\"`."},"options":{"a":"print(\"Item: \" + item)","b":"return \"Item: \" + item","c":"input(\"Item: \" + item)","d":"def \"Item: \" + item"}}},"tryIt":{"try_print_vs_return_checkpoint":{"title":"Try it yourself","prompt":"Define `add(a, b)` so it returns the sum. Then print `add(3, 4)`."},"try_print_vs_return_sketch0":{"title":"Try it yourself","prompt":"Call a display-only function directly so its implicit `None` result is not printed."},"try_print_vs_return_sketch1":{"title":"Try it yourself","prompt":"Store a returned number and reuse it in another expression."},"try_print_vs_return_sketch2":{"title":"Try it yourself","prompt":"Fix a function that prints when its caller needs a returned string."},"allowReveal":true}},"scope-and-local-variables":{"label":"Scope and Local Variables","summary":"Use local variables safely inside functions, recognize that parameters are local names, keep same-named outside values separate, and return local results when the caller needs them.","cards":{"sketch0":{"title":"Local variables belong to the function call"},"sketch1":{"title":"Parameters are local, even when names match outside"},"sketch2":{"title":"Return local results to the caller"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-q1":{"title":"Find the local variable","prompt":"In this code, which name is local to the function?\n\n```python\ncolor = \"blue\"\n\ndef paint():\n shade = \"dark\"\n return color + \" \" + shade\n```","hint":"Look for the name created inside `paint()`.","help":{"concept":"A local variable is created inside a function and is meant to be used only during that function call.","hint_1":"`color` is assigned before the function starts. Check which name is assigned inside the function body.","hint_2":"The local name is the one introduced on the line `... = \"dark\"` inside `paint()`."},"options":{"a":"color","b":"paint","c":"shade","d":"return"}},"sc-q2":{"title":"Parameter scope","prompt":"What is true about a parameter like `name` in `def greet(name):`?","hint":"Think about where the parameter can be used directly.","help":{"concept":"Parameters are local names created for a function call, so they belong to that function's scope.","hint_1":"A parameter gets its value when the function is called, not everywhere in the program.","hint_2":"Ask whether `name` is meant to exist only inside `greet(...)` or in all code automatically."},"options":{"a":"It exists only inside the function call unless returned or passed elsewhere.","b":"It automatically becomes a global variable.","c":"It can only store numbers.","d":"It disappears before the function starts."}},"mc-q1":{"title":"Choose the local names","prompt":"Which names are local in this code? Choose all that apply.\n\n```python\ntax = 5\n\ndef total(price):\n fee = 2\n final_price = price + fee + tax\n return final_price\n```","hint":"Reject any choice that changes the named values, branch order, or output.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"tax","b":"price","c":"fee","d":"final_price"}},"mc-q2":{"title":"Why local scope helps","prompt":"Why are local variables useful? Choose all correct answers.","hint":"Think about how functions stay organized and avoid name mix-ups.","help":{"concept":"Local scope helps functions stay independent, readable, and safer because temporary names do not leak into the rest of the program.","hint_1":"A good answer should mention keeping function work separate or preventing accidental reuse of temporary names.","hint_2":"Look for benefits like reducing conflicts and making each function manage its own temporary data."},"options":{"a":"They help prevent temporary names inside one function from interfering with other code.","b":"They make it easier for a function to keep its own working values.","c":"They force every variable in a program to have the same name.","d":"They automatically print returned values."}},"dr-q1":{"title":"Order a function call","prompt":"Put these steps in the correct order for what happens when `double(4)` runs in a function that returns `number * 2`.","hint":"Start with the call, then the parameter gets a value, then the calculation happens, then the result is returned.","help":{"concept":"A function call gives values to parameters, runs the function body, computes a result, and then returns that result.","hint_1":"The parameter cannot be used until the function is called with an argument.","hint_2":"After `number` gets `4`, the multiplication happens before the value is sent back."},"tokens":{"t1":"Call `double(4)`","t2":"Set local parameter `number` to `4`","t3":"Compute `number * 2`","t4":"Return the result"}},"dr-q2":{"title":"Trace local variable creation","prompt":"Arrange the steps to describe this function call correctly.\n\n```python\ndef greet(person):\n message = \"Hi \" + person\n return message\n```","hint":"The argument fills the parameter first, then the local variable is built, then the function returns it.","help":{"concept":"During a function call, the argument becomes the parameter value, local variables are created from that value, and the return statement sends the final result back.","hint_1":"`person` gets its value before `message` can be created.","hint_2":"The returned value comes last, after the string has been built inside the function."},"tokens":{"t1":"Pass an argument into `person`","t2":"Create local variable `message`","t3":"Build the text `\"Hi \" + person`","t4":"Return `message`"}},"fb-q1":{"title":"Complete the local assignment","prompt":"Choose the missing word to make `score` a local variable inside the function.","hint":"The blank should be the variable name being assigned inside the function.","help":{"concept":"A variable assigned inside a function becomes local to that function call.","hint_1":"The line is creating a new name inside the function body.","hint_2":"Match the blank to the variable described as belonging only to the function call."},"template":"def show_score():\n [blank1] = 10\n return score","choices":["score","return","show_score","def"]},"fb-q2":{"title":"Complete the parameter use","prompt":"Fill the blank with the correct local name.","hint":"Use the parameter name from the function header.","help":{"concept":"A parameter is a local name, so code inside the function should use that parameter name directly.","hint_1":"The function header already tells you the local name to use.","hint_2":"Look at the parameter position inside the function header and choose the same name used by the function body."},"template":"def triple(value):\n return [blank1] * 3","choices":["value","triple","return","3"]},"code-q1":{"title":"Return a local calculation","prompt":"Write `add_tax(price)` so it calculates `price + 5`, stores that result in a local variable named `total`, and then returns `total`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def add_tax(price):\n # store the result in a local variable named total\n # then return it\n pass","solutionCode":"def add_tax(price):\n total = price + 5\n return total","checks":{"0":{"message":"add_tax should return price plus 5."},"1":{"message":"add_tax should work for a different number too."},"2":{"message":"Return the value instead of printing it."}}},"code-q2":{"title":"Use a parameter as a local name","prompt":"Write `make_label(word)` so it builds the finished string in a local variable named `label`, then returns `label`.","hint":"Read the task \"Use a parameter as a local name\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def make_label(word):\n # create a local variable named label\n # return the finished string\n pass","solutionCode":"def make_label(word):\n label = \"Item: \" + word\n return label","checks":{"0":{"message":"make_label should prefix the word with `Item: `."},"1":{"message":"make_label should work with another input word."},"2":{"message":"Return the string instead of printing it."}}},"code-q3":{"title":"Compute with two local variables","prompt":"Write `rectangle_area(width, height)` so it computes the area, stores it in a local variable named `area`, and returns `area`.","hint":"Read the task \"Compute with two local variables\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def rectangle_area(width, height):\n # create a local variable named area\n # return the area\n pass","solutionCode":"def rectangle_area(width, height):\n area = width * height\n return area","checks":{"0":{"message":"rectangle_area should multiply width by height."},"1":{"message":"rectangle_area should work for another pair of numbers."},"2":{"message":"Return the area instead of printing it."}}},"try-scope-and-local-variables-checkpoint":{"title":"Use a local variable","prompt":"Define `make_message(name)` with a local variable named `message`, then return it. Print the result for `Ava`.","hint":"Create the message inside the function.","help":{"concept":"A local variable exists inside the function where it is created.","hint_1":"Create the message inside the function.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"def make_message(name):\n # Create a local variable named message.\n pass\n\nprint(make_message(\"Ava\"))\n","solutionCode":"def make_message(name):\n message = f\"Hello, {name}!\"\n return message\n\nprint(make_message(\"Ava\"))\n"},"try-scope-and-local-variables-sketch0":{"title":"Create and return a local calculation","prompt":"Complete `add_fee(price)`. Inside the function, create the local variable a local variable named `total` that stores the result of increasing `price` by 3, then return `total`. The caller already reads a price and prints the returned result.","hint":"Both the `total` assignment and `return total` belong inside the function body.","help":{"concept":"A local variable can hold an intermediate result while the function is running.","hint_1":"Create `total = price + 3` under the `def` line.","hint_2":"Return that local value with `return total`."},"starterCode":"def add_fee(price):\n # Create local variable total = price + 3.\n # Then return total.\n pass\n\nprice = int(input())\nprint(add_fee(price))\n","solutionCode":"def add_fee(price):\n total = price + 3\n return total\n\nprice = int(input())\nprint(add_fee(price))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-scope-and-local-variables-sketch1":{"title":"Keep an outside value separate from a parameter","prompt":"The program reads an outside variable named `count`. Complete `next_count(count)` so it creates local variable a local variable named `updated` that stores `count` increased by 1 and returns `updated`. The program must print the returned next count and then print the original outside `count`, which should remain unchanged.","hint":"The parameter named `count` is local to `next_count`; calculate a new local `updated` value instead of changing the outside assignment.","help":{"concept":"A parameter can have the same name as an outside variable without turning that outside variable into the function's local storage.","hint_1":"Inside the function, write `updated = count + 1`.","hint_2":"Return `updated`; do not add another top-level assignment to `count`."},"starterCode":"count = int(input())\n\ndef next_count(count):\n # Create local variable updated = count + 1.\n # Return updated.\n pass\n\nprint(next_count(count))\nprint(count)\n","solutionCode":"count = int(input())\n\ndef next_count(count):\n updated = count + 1\n return updated\n\nprint(next_count(count))\nprint(count)\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}}},"try-scope-and-local-variables-sketch2":{"title":"Return a local value to the caller","prompt":"The starter creates local variable `message` inside `make_message(name)`, but then incorrectly tries to use `message` outside the function. Fix the program by returning the local `message`, storing the returned value in a caller-side variable named `result`, and printing `result`.","hint":"The outside code cannot reach the function's local `message` directly; send its value back with `return`.","help":{"concept":"Returning a local value does not expose the local variable itself; it gives the caller a value that the caller can store under its own name.","hint_1":"Inside the function, add `return message`.","hint_2":"Outside the function, use `result = make_message(name)` and then `print(result)`."},"starterCode":"def make_message(name):\n message = \"Hello, \" + name\n # Return the local message so the caller can use its value.\n pass\n\nname = input()\nmake_message(name)\nprint(message)\n","solutionCode":"def make_message(name):\n message = \"Hello, \" + name\n return message\n\nname = input()\nresult = make_message(name)\nprint(result)\n","sourceChecks":{"0":{"message":"Call `make_message(...)` because that function call is explicitly required by the prompt."}}},"sc-local-variable":{"title":"Identify a local variable","prompt":"In `def total(price): fee = 2; return price + fee`, which name is created locally inside the function body?","hint":"Look for the assignment that happens inside the function.","help":{"concept":"A name assigned inside a function is local to that function call unless Python is explicitly told otherwise.","hint_1":"`price` is a parameter; it receives its value when the function is called.","hint_2":"`fee = 2` creates a working variable inside the function body."},"options":{"a":"fee","b":"total","c":"return","d":"def"}},"sc-local-outside":{"title":"Use a local name outside the function","prompt":"A function creates `message = \"Ready\"` inside its body but does not return it. What happens if code after the function call tries `print(message)`?","hint":"The name was created only inside the function.","help":{"concept":"A local variable is not directly available to unrelated code after the function call finishes.","hint_1":"Displaying or returning a value is different from making the local variable itself available outside.","hint_2":"The outside code does not have its own `message` assignment."},"options":{"a":"It prints Ready","b":"Python reports that `message` is not defined there","c":"It automatically calls the function again","d":"It turns `message` into a parameter"}},"sc-parameter-local":{"title":"Parameter scope","prompt":"What is true about `count` in `def add_one(count):`?","hint":"A parameter is a name that receives an argument for one function call.","help":{"concept":"Parameters are local names inside the function call.","hint_1":"The caller supplies an argument value.","hint_2":"Inside the function, that value is available through the local parameter name `count`."},"options":{"a":"It is local to the function call","b":"It automatically changes every outside variable named count","c":"It can only hold integers","d":"It exists before the function is called"}},"sc-same-name-separate":{"title":"Same name, separate value","prompt":"Suppose `count = 5` exists outside a function and `def add_one(count): return count + 1`. After `print(add_one(count))`, what is the outside `count` still equal to?","hint":"The parameter receives the value 5, but the function does not assign to the outside variable.","help":{"concept":"A parameter can have the same spelling as an outside variable while still being a separate local name.","hint_1":"The call returns `6`.","hint_2":"Nothing in the function changes the caller's `count = 5` assignment."},"options":{"a":"5","b":"6","c":"None","d":"The function name"}}},"tryIt":{"try_scope_and_local_variables_checkpoint":{"title":"Try it yourself","prompt":"Define `make_message(name)` with a local variable named `message`, then return it. Print the result for `Ava`."},"try_scope_and_local_variables_sketch0":{"title":"Try it yourself","prompt":"Complete `add_fee(price)`. Inside the function, create the local variable a local variable named `total` that stores the result of increasing `price` by 3, then return `total`. The caller already reads a price and prints the returned result."},"try_scope_and_local_variables_sketch1":{"title":"Try it yourself","prompt":"The program reads an outside variable named `count`. Complete `next_count(count)` so it creates local variable a local variable named `updated` that stores `count` increased by 1 and returns `updated`. The program must print the returned next count and then print the original outside `count`, which should remain unchanged."},"try_scope_and_local_variables_sketch2":{"title":"Try it yourself","prompt":"Return a local result and store that value under a caller-side variable."},"allowReveal":true}},"using-imports-and-helper-files":{"label":"Using Imports and Helper Files","summary":"Move reusable functions into sibling Python module files, import those functions into `main.py`, and connect multiple focused modules without changing the program's behavior.","cards":{"sketch0":{"title":"A Python file can be imported as a module"},"sketch1":{"title":"One module can hold related helpers"},"sketch2":{"title":"main.py can connect multiple helper modules"},"quiz":{"title":"Check your understanding"}},"quiz":{"q1":{"title":"Why split code into files?","prompt":"Why would a Python project put reusable functions in files such as `tools/names.py` instead of putting every line in `main.py`?","hint":"Think about keeping the main app readable and reusing the same logic later.","help":{"concept":"A module file can hold reusable functions. `main.py` can stay focused on the app flow: read input, call functions, and print results.","hint_1":"Look for the option about organization and reuse.","hint_2":"The goal is not to make more work. The goal is to keep each file responsible for a clear job."},"options":{"a":"It keeps reusable code organized and lets `main.py` import it","b":"It makes Python ignore errors in the imported file","c":"It means the project can only run with one input value","d":"It prevents functions from returning values"}},"q2":{"title":"Choose the direct import","prompt":"You created `tools/names.py` with a function named `clean_name`. Which line imports that function into `main.py`?","hint":"The path uses the folder name, then the file name without `.py`, then the function name.","help":{"concept":"To import from a module inside a folder, use `from folder.file import function`. For `tools/names.py`, the module path is `tools.names`.","hint_1":"Do not include `.py` in the import line.","hint_2":"The correct form starts with `from tools.names import ...`."},"options":{"a":"from tools.names import clean_name","b":"from tools/names.py import clean_name","c":"import clean_name from tools.names","d":"from clean_name import tools.names"}},"q3":{"title":"Good module responsibilities","prompt":"Choose all examples that are good jobs for a small module file in this lesson.","hint":"Pick jobs that are reusable and focused.","help":{"concept":"Good module files usually hold related functions, such as text cleanup, formatting, scoring, or report building.","hint_1":"A module should have a clear purpose.","hint_2":"Avoid choices that put unrelated random code into one file."},"options":{"a":"`tools/names.py` cleans and formats names","b":"`tools/badges.py` builds badge text from a name and role","c":"`tools/random_everything.py` mixes unrelated code with no clear job","d":"`main.py` must copy every function from every module before it can run"}},"q4":{"title":"Valid imported calls","prompt":"Which calls are valid after the matching import? Choose all correct answers.","hint":"Match the call style to the import style.","help":{"concept":"After `from tools.names import clean_name`, call `clean_name(...)` directly. After `import tools.badges as badges`, call `badges.make_badge(...)`.","hint_1":"Direct imports use the function name directly.","hint_2":"Alias imports use the alias before the dot."},"options":{"a":"After `from tools.names import clean_name`, use `clean_name(\" ava \")`","b":"After `import tools.badges as badges`, use `badges.make_badge(\"Ava\", \"coder\")`","c":"After `from tools.names import clean_name`, use `tools.names.clean_name(\"Ava\")` without importing `tools`","d":"After `import tools.badges as badges`, use `make_badge.badges(\"Ava\")`"}},"q5":{"title":"Order the module workflow","prompt":"Put these steps in the order you would use when adding your own module file to a small app.","hint":"Create the file before importing from it.","help":{"concept":"Python can import a module only after the file exists in the expected folder path. Then `main.py` can call functions from that file.","hint_1":"The folder and file come before the import.","hint_2":"The function call happens after the import line."},"tokens":{"t1":"Create the `tools` folder","t2":"Create a module file such as `tools/names.py`","t3":"Define a function inside that module file","t4":"Import and call the function from `main.py`"}},"q6":{"title":"Build the import flow","prompt":"Arrange these lines so `main.py` imports a formatter and prints the returned result.","hint":"Import first, then call, then print.","help":{"concept":"A main file usually imports the function it needs, calls it with data, and prints or stores the returned value.","hint_1":"The import line must run before the function call.","hint_2":"Print the stored message after the function returns it."},"tokens":{"t1":"from tools.reports import mission_report","t2":"message = mission_report(\"SCOUT badge: Zoe\", 18)","t3":"print(message)"}},"q7":{"title":"Complete the function import","prompt":"Fill in the missing function name to import it from `tools.names`.","hint":"This is the function that cleans extra spaces and capitalization.","help":{"concept":"`from tools.names import clean_name` imports the `clean_name` function from the `names.py` file inside the `tools` folder.","hint_1":"The missing word is the function name, not the folder name.","hint_2":"Choose the name that describes cleaning a name."},"template":"from tools.names import [blank1]","choices":["clean_name","tools","names.py","input"]},"q8":{"title":"Complete the module path","prompt":"Fill in the missing folder name in this import line.","hint":"The module files for this project live inside one folder.","help":{"concept":"The import path `tools.badges` means Python should look for `badges.py` inside the `tools` folder.","hint_1":"Do not type `.py` in the import path.","hint_2":"Choose the folder that contains `badges.py`."},"template":"from [blank1].badges import make_badge","choices":["tools","badges.py","main","print"]},"q9":{"title":"Create a name-cleaning module","prompt":"Practice creating and importing a small helper module. Create a `tools` folder, add `tools/names.py`, and define `clean_name(text)` there. Then import `clean_name` from `tools.names` in `main.py`, clean the input name, and print it. For input `aVA`, the output should be `Ava`.","hint":"The required path is `tools/names.py`. The import line in `main.py` should be `from tools.names import clean_name`.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"# Create a folder named tools.\n# Inside it, create tools/names.py.\n# Define clean_name(text) in that file.\n\nraw_name = input()\n\n# Import clean_name from tools.names.\n# Print the cleaned name.\n","solutionFiles":{"main_py":{"content":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Import from tools.names."},"1":{"message":"Define clean_name(text) inside tools/names.py."},"2":{"message":"clean_name should strip whitespace."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"q10":{"title":"Add a badge module","prompt":"The helper folder needs one more tool. Create `tools/badges.py`, import `make_badge` from `tools.badges`, clean the input name, build the badge text, and print it.\n\nFor example, if the inputs are `lina` and `artist`, your program should print:\n`ARTIST badge: Lina`.","hint":"Create `tools/badges.py`, then import with `from tools.badges import make_badge`.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"from tools.names import clean_name\n\nraw_name = input()\nrole = input()\n\n# Create tools/badges.py.\n# Import make_badge from tools.badges.\n# Clean the name, build the badge, and print it.\n","starterFiles":{"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Import from tools.badges."},"1":{"message":"Define make_badge in tools/badges.py."},"2":{"message":"make_badge should uppercase the role."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"q11":{"title":"Build a mission report module","prompt":"Practice connecting helper modules into one report. Create `tools/reports.py`, import `mission_report` from `tools.reports`, and print the finished mission report. For inputs `zoe`, `scout`, and `18`, the output should be `Mission report: SCOUT badge: Zoe has 18 points`.","hint":"This step combines three files: `tools/names.py`, `tools/badges.py`, and your new `tools/reports.py`.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\n\nraw_name = input()\nrole = input()\npoints = int(input())\n\n# Create tools/reports.py.\n# Import mission_report from tools.reports.\n# Print the final mission report.\n","starterFiles":{"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"solutionFiles":{"main_py":{"content":"from tools.names import clean_name\nfrom tools.badges import make_badge\nfrom tools.reports import mission_report\n\nraw_name = input()\nrole = input()\npoints = int(input())\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(mission_report(badge, points))\n"},"tools_init_py":{"content":"# Tools package for this mini app.\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"},"tools_reports_py":{"content":"def mission_report(badge, points):\n return f\"Mission report: {badge} has {points} points\"\n"}},"sourceChecks":{"0":{"message":"Import from tools.reports."},"1":{"message":"Define mission_report in tools/reports.py."},"2":{"message":"Call mission_report() from main.py."}},"solutionCode":"from tools.names import clean_name\nfrom tools.badges import make_badge\nfrom tools.reports import mission_report\n\nraw_name = input()\nrole = input()\npoints = int(input())\nname = clean_name(raw_name)\nbadge = make_badge(name, role)\nprint(mission_report(badge, points))\n"},"try-using-imports-and-helper-files-checkpoint":{"title":"Import from a helper file","prompt":"Build this as a small two-file program.\n\n1. Create `tools/names.py`.\n2. In `tools/names.py`, define `clean_name(text)`.\n3. In `main.py`, import `clean_name` with `from tools.names import clean_name`.\n4. Read one name with `input()`, clean it, and print the result.","hint":"Create `tools/names.py` first, then import `clean_name` in `main.py`.","help":{"concept":"A helper module lets `main.py` stay short while another file handles one focused job.","hint_1":"Put `clean_name(text)` in `tools/names.py`.","hint_2":"In `main.py`, import `clean_name`, call it with the raw input, and print the cleaned name."},"starterCode":"raw_name = input()\n\n# Import clean_name from tools.names.\n# Print the cleaned name.\n","solutionFiles":{"main_py":{"content":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Import from tools.names."},"1":{"message":"Define clean_name(text) inside tools/names.py."},"2":{"message":"clean_name should strip whitespace."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from tools.names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"try-using-imports-and-helper-files-sketch0":{"title":"Move a helper into names.py","prompt":"This program already works, but `clean_name` is still defined inside `main.py`. Refactor it without changing the output: move `clean_name(text)` into a new sibling file named `names.py`, then import it in `main.py` with a from-import that brings `clean_name` in from the `names` module.","hint":"The function body moves to `names.py`; `main.py` keeps the input and output flow.","help":{"concept":"A Python helper file becomes a module that another file can import.","hint_1":"Create `names.py` beside `main.py` and put `clean_name(text)` there.","hint_2":"Remove the local definition from `main.py` and add `from names import clean_name`."},"starterCode":"def clean_name(text):\n return text.strip().title()\n\nraw_name = input()\nprint(clean_name(raw_name))\n","solutionFiles":{"main_py":{"content":"from names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `clean_name` from `names`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"clean_name should strip spaces."},"3":{"message":"clean_name should title-case the name."}},"solutionCode":"from names import clean_name\n\nraw_name = input()\nprint(clean_name(raw_name))\n","starterFiles":{"main_py":{"content":"def clean_name(text):\n return text.strip().title()\n\nraw_name = input()\nprint(clean_name(raw_name))\n"}}},"try-using-imports-and-helper-files-sketch1":{"title":"Move related helpers into text_tools.py","prompt":"This working program defines two related text helpers in `main.py`. Refactor it without changing the output: move both `clean_word(text)` and `make_label(word)` into a sibling file named `text_tools.py`. In `main.py`, import both functions with one from-import that brings both `clean_word` and `make_label` in from the `text_tools` module.","hint":"Both related helper functions move to the same module; the input and print stay in `main.py`.","help":{"concept":"One module can expose several related helper functions.","hint_1":"Create `text_tools.py` with both function definitions.","hint_2":"In `main.py`, import both names from `text_tools` and keep calling them in the existing flow."},"starterCode":"def clean_word(text):\n return text.strip().lower()\n\ndef make_label(word):\n return \"Word: \" + word\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n","solutionFiles":{"main_py":{"content":"from text_tools import clean_word, make_label\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"},"text_tools_py":{"content":"def clean_word(text):\n return text.strip().lower()\n\ndef make_label(word):\n return \"Word: \" + word\n"}},"sourceChecks":{"0":{"message":"Use the requested import for `clean_word` from `text_tools`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"solutionCode":"from text_tools import clean_word, make_label\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n","starterFiles":{"main_py":{"content":"def clean_word(text):\n return text.strip().lower()\n\ndef make_label(word):\n return \"Word: \" + word\n\nraw_word = input()\nword = clean_word(raw_word)\nprint(make_label(word))\n"}}},"try-using-imports-and-helper-files-sketch2":{"title":"Connect two existing helper modules","prompt":"`names.py` already defines `clean_name(text)` and `badges.py` already defines `make_badge(name, role)`. `main.py` currently duplicates both jobs inline. Refactor only the main flow so it imports both helpers, cleans the input name with `clean_name`, then builds the badge with `make_badge`. The program's output must stay the same.","hint":"The helper files are already complete; `main.py` should import and connect them.","help":{"concept":"A main file can coordinate multiple focused modules by passing one helper's returned value into another.","hint_1":"Import `clean_name` from `names` and `make_badge` from `badges`.","hint_2":"Use `name = clean_name(raw_name)` and then `print(make_badge(name, role))`."},"starterCode":"raw_name = input()\nrole = input()\n\nname = raw_name.strip().title()\nprint(f\"{role.upper()} badge: {name}\")\n","solutionFiles":{"main_py":{"content":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\n\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n"},"tools_names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"tools_badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}},"sourceChecks":{"0":{"message":"Import the sibling `names` helper module in `main.py` as the prompt requires."},"1":{"message":"Import the sibling `badges` helper module in `main.py` as the prompt requires."},"2":{"message":"Call `clean_name(...)` because that function call is explicitly required by the prompt."},"3":{"message":"Call `make_badge(...)` because that function call is explicitly required by the prompt."},"4":{"message":"Call clean_name in main.py."},"5":{"message":"Call make_badge in main.py."}},"solutionCode":"from names import clean_name\nfrom badges import make_badge\n\nraw_name = input()\nrole = input()\n\nname = clean_name(raw_name)\nprint(make_badge(name, role))\n","starterFiles":{"main_py":{"content":"raw_name = input()\nrole = input()\n\nname = raw_name.strip().title()\nprint(f\"{role.upper()} badge: {name}\")\n"},"names_py":{"content":"def clean_name(text):\n return text.strip().title()\n"},"badges_py":{"content":"def make_badge(name, role):\n return f\"{role.upper()} badge: {name}\"\n"}}},"sc-file-to-module":{"title":"Import from a sibling file","prompt":"`names.py` is beside `main.py` and defines `clean_name`. Which line imports that function into `main.py`?","hint":"Use the Python file name without the `.py` extension.","help":{"concept":"A sibling file such as `names.py` can be imported by its module name `names`.","hint_1":"The module part is `names`, not `names.py`.","hint_2":"A direct function import uses `from names import clean_name`."},"options":{"a":"from names import clean_name","b":"from names.py import clean_name","c":"from clean_name import names","d":"import clean_name from names"}},"sc-direct-call":{"title":"Call a directly imported function","prompt":"After `from names import clean_name`, which expression calls the imported function with `raw_name`?","hint":"A directly imported function is called by its function name.","help":{"concept":"With `from module import function`, the imported function name is available directly in the importing file.","hint_1":"You do not include `.py` when calling the function.","hint_2":"Use `clean_name(raw_name)`."},"options":{"a":"clean_name(raw_name)","b":"names.py.clean_name(raw_name)","c":"import clean_name(raw_name)","d":"from clean_name(raw_name)"}},"sc-module-responsibility":{"title":"Choose a focused helper module","prompt":"Which file responsibility is the clearest fit for a small helper module?","hint":"Keep related reusable functions together.","help":{"concept":"A helper module is easiest to understand when its functions serve one related responsibility.","hint_1":"Name-related cleanup functions belong naturally together.","hint_2":"Avoid a file that mixes unrelated input, math, formatting, and random experiments."},"options":{"a":"`names.py` contains functions for cleaning and formatting names","b":"`everything.py` contains unrelated code from the entire program","c":"`main.py` copies every helper function before using it","d":"`random.py` stores unrelated temporary experiments"}},"sc-main-role":{"title":"What main.py should do","prompt":"After name cleanup lives in `names.py` and badge formatting lives in `badges.py`, what is a good responsibility for `main.py`?","hint":"The main file can coordinate the app instead of duplicating helper logic.","help":{"concept":"`main.py` can read input, call imported helpers, and connect their returned values into the program flow.","hint_1":"The helper modules already own cleanup and badge formatting.","hint_2":"The main file should import and call them rather than rewrite them."},"options":{"a":"Read input and connect the imported helper functions","b":"Copy the full contents of every helper file","c":"Rename every imported function before it can run","d":"Avoid calling any helper function"}}},"tryIt":{"try_using_imports_and_helper_files_checkpoint":{"title":"Try it yourself","prompt":"Build this as a small two-file program.\n\n1. Create `tools/names.py`.\n2. In `tools/names.py`, define `clean_name(text)`.\n3. In `main.py`, import `clean_name` with `from tools.names import clean_name`.\n4. Read one name with `input()`, clean it, and print the result."},"try_using_imports_and_helper_files_sketch0":{"title":"Try it yourself","prompt":"This program already works, but `clean_name` is still defined inside `main.py`. Refactor it without changing the output: move `clean_name(text)` into a new sibling file named `names.py`, then import it in `main.py` with a from-import that brings `clean_name` in from the `names` module."},"try_using_imports_and_helper_files_sketch1":{"title":"Try it yourself","prompt":"This working program defines two related text helpers in `main.py`. Refactor it without changing the output: move both `clean_word(text)` and `make_label(word)` into a sibling file named `text_tools.py`. In `main.py`, import both functions with one from-import that brings both `clean_word` and `make_label` in from the `text_tools` module."},"try_using_imports_and_helper_files_sketch2":{"title":"Try it yourself","prompt":"Refactor `main.py` to connect two existing sibling helper modules."},"allowReveal":true}}},"python-7-files-exceptions-and-data-cleaning":{"module-7-clean-student-records":{"label":"Module Project: Clean Student Records","summary":"Turn a messy student CSV export into a validated clean CSV by combining DictReader, cleaning functions, specific exception handling, lists, and text-file writing, while keeping row-cleaning logic in a reusable helper module.","cards":{"sketch0":{"title":"A messy student export needs a reliable cleaner"},"project":{"title":"Clean Student Records"}},"projectSteps":{"mp_1":{"title":"Build the cleaning helper"},"mp_2":{"title":"Collect only valid student records"},"mp_3":{"title":"Write the cleaned CSV file"},"mp_4":{"title":"Verify the saved clean CSV"}},"quiz":{"mp-1-read-student-file":{"title":"Build the cleaning helper","prompt":"Start from the CSV preview. Create a sibling helper file named `cleaning.py` and define `clean_row(row)` there. In `main.py`, import it with `from cleaning import clean_row`. Clean the name with whitespace trimming followed by title-case normalization and the score text with `strip()`. Return `None` for an empty cleaned name, invalid integer score text, or a score outside 0 through 100. Otherwise return `{\"name\": name, \"score\": score}`. Then print `clean_row(row)` for every imported row so you can inspect which rows are accepted or rejected.","hint":"Put the reusable row-cleaning function in `cleaning.py`; keep CSV orchestration in `main.py` and import the helper directly.","help":{"concept":"The helper should produce one dependable result: a cleaned dictionary for valid input or `None` for rejected input.","hint_1":"Check `name == \"\"` before attempting the score conversion.","hint_2":"Catch exactly `ValueError`, then apply the 0-through-100 range check."},"starterCode":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n"},"output_clean_students_csv":{"content":"old export\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Use the explicitly requested dictionary field `name`."},"2":{"message":"Use the explicitly requested dictionary field `score`."},"3":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"4":{"message":"Use `title()` because that method is explicitly required by the prompt."},"5":{"message":"Import `clean_row` from the sibling `cleaning.py` helper as the project requires."}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"mp-2-clean-one-row":{"title":"Collect only valid student records","prompt":"Keep `clean_row(row)` exactly as it works now. Replace the row-by-row preview with a `records` list. Loop through `csv.DictReader`, call `clean_row(row)` once per row, and append only results that are not `None`. Print `records` after the loop. Keep `clean_row(row)` in the sibling `cleaning.py` file and keep importing it into `main.py`; do not copy the helper back into the entry file.","hint":"The cleaner already decides whether a row is valid; this step should only collect accepted results.","help":{"concept":"Separating row validation from record collection keeps each responsibility small and reusable.","hint_1":"Store the helper result in `record` instead of calling the function several times.","hint_2":"Append only when `record is not None`."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","sourceChecks":{"0":{"message":"Use a `for` loop as the prompt requests."},"1":{"message":"Call `clean_row(...)` because that function call is explicitly required by the prompt."},"2":{"message":"Print the completed `records` list itself after the collection loop."},"3":{"message":"Keep the required `clean_row(row)` function in `cleaning.py`."}}},"mp-3-skip-bad-rows":{"title":"Write the cleaned CSV file","prompt":"Keep the valid-record builder. Replace the list preview with a deliverable file. Open `output/clean_students.csv` in write mode, write the header `name,score`, then write one cleaned `name,score` line for every record. Finally print `Wrote <count> clean records`. The supplied output file contains old text so write mode must replace it. Keep `clean_row(row)` in the sibling `cleaning.py` file and keep importing it into `main.py`; do not copy the helper back into the entry file.","hint":"Use the `records` list as the source for the final file instead of cleaning the CSV a second time.","help":{"concept":"Write mode should replace the old export, then one `file.write(...)` call can write each cleaned record.","hint_1":"Write the header first: `name,score\\n`.","hint_2":"Loop through `records` and write each name and numeric score on one line."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Keep the required `clean_row(row)` function in `cleaning.py`."}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n"},"mp-4-write-clean-records":{"title":"Verify the saved clean CSV","prompt":"Keep the working cleaner and output writer. After the completion message, reopen `output/clean_students.csv` in read mode and print exactly what was saved. The final output should show the completion message followed by the header and the three accepted records. Keep `clean_row(row)` in the sibling `cleaning.py` file and keep importing it into `main.py`; do not copy the helper back into the entry file.","hint":"The saved file is the deliverable, so verify the artifact itself instead of trusting only the in-memory list.","help":{"concept":"Reopen the same path after the write block has finished.","hint_1":"Print `file.read()` with `end=\"\"` so the file contents appear exactly as saved.","hint_2":"The output file should contain only the header and accepted cleaned rows."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n","starterFiles":{"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n\nwith open(\"output/clean_students.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n"}},"sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Keep the required `clean_row(row)` function in `cleaning.py`."}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nwith open(\"output/clean_students.csv\", \"w\") as file:\n file.write(\"name,score\\n\")\n for record in records:\n file.write(record[\"name\"] + \",\" + str(record[\"score\"]) + \"\\n\")\n\nprint(\"Wrote \" + str(len(records)) + \" clean records\")\n\nwith open(\"output/clean_students.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"try-module-7-clean-student-records-sketch0":{"title":"Inspect the student export","prompt":"Open `data/students.csv` in read mode with `csv.DictReader`. Loop through every row and print `name:score` using the named CSV columns. Do not clean or reject anything yet; this preview is only for seeing the imported data.","hint":"Start with the file exactly as it arrived so you can see which rows need cleaning.","help":{"concept":"A data-cleaning project begins by reading the real source file and understanding its shape before transforming it.","hint_1":"Create `reader = csv.DictReader(file)` inside the open-file block.","hint_2":"Loop through `reader` and use `row[\"name\"]` and `row[\"score\"]` rather than hard-coded output."},"starterCode":"import csv\n\n# Open data/students.csv in read mode.\n# Use csv.DictReader and print each row as name:score.\n","solutionCode":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n","sourceChecks":{"0":{"message":"Use the requested import involving `csv`."},"1":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"2":{"message":"Use a `for` loop as the prompt requests."},"3":{"message":"Title-case the student name."}},"starterFiles":{"main_py":{"content":"import csv\n\n# Open data/students.csv in read mode.\n# Use csv.DictReader and print each row as name:score.\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nwith open(\"data/students.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n"},"data_students_csv":{"content":"name,score\n Ava ,92\nMia,not-a-score\n ,75\nZoe,87\n leo ,74\nNia,105\n"},"output_clean_students_csv":{"content":"old export\n"}}}},"tryIt":{"try_module_7_clean_student_records_sketch0":{"title":"Try it yourself","prompt":"Inspect the student export with `csv.DictReader` before the project starts."},"allowReveal":true}},"reading-text-files":{"label":"Reading Text Files","summary":"Open existing text files with `with open(..., \"r\")`, read a whole file with `.read()` or process it one line at a time, and use relative paths for files inside the workspace.","cards":{"sketch0":{"title":"Open and read a whole text file"},"sketch1":{"title":"Process a file one line at a time"},"sketch2":{"title":"Read a file from a relative path"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-read-mode":{"title":"Read mode","prompt":"Which file mode is used to open a text file for reading?","hint":"Use the question wording and the lesson example to narrow the choices.","help":{"concept":"This question checks a specific idea from the lesson, not general test-taking strategy.","hint_1":"Compare each option to the exact topic named in the question.","hint_2":"Remove options that do not match the concept or evidence named in the question."},"options":{"a":"r","b":"w","c":"a","d":"x"}},"sc-relative-path":{"title":"Relative path example","prompt":"Which path correctly refers to a file named `story.txt` inside a folder named `data`?","hint":"Use the folder name, then the file name.","help":{"concept":"A relative path describes a file's location from the current workspace location using folder names separated by `/`.","hint_1":"The folder should come before the file name.","hint_2":"Choose the option that looks like folder slash file."},"options":{"a":"story.txt/data","b":"data/story.txt","c":"/data/story.txt","d":"data-story.txt"}},"mc-with-open-benefits":{"title":"Why use with open","prompt":"Choose all true statements about using `with open(...) as file:` when reading text files.","hint":"Think about what `with` does for the file resource and how you access the file inside the block.","help":{"concept":"`with open(...) as file:` creates a managed file block. You use the file variable inside the block, and Python handles closing the file afterward.","hint_1":"Look for statements about automatic closing and using the variable after `as`.","hint_2":"Two statements are correct: one about cleanup and one about the file variable name."},"options":{"a":"It helps make sure the file is closed after the block ends.","b":"It creates a variable like `file` that you can call `.read()` on.","c":"It always writes new text into the file before reading.","d":"It only works for files in the same folder, not nested folders."}},"mc-read-methods":{"title":"Reading methods","prompt":"Choose all statements that are true about `read()` and `readlines()`.","hint":"One returns a single string, and the other returns a list of lines.","help":{"concept":"`read()` gets the whole file as one string, while `readlines()` returns a list where each item is a line, often including newline characters.","hint_1":"Look for the options describing one big string and a list of lines.","hint_2":"Two options are correct: one mentions a single string, and one mentions newline characters in line items."},"options":{"a":"`read()` can return the whole file as one string.","b":"`readlines()` returns a list of lines.","c":"`read()` always removes every newline character automatically.","d":"`readlines()` returns one number for each line."}},"dr-read-file-steps":{"title":"Order the reading steps","prompt":"Put these steps in the correct order for reading and printing a file's contents.","hint":"Start by opening the file, then read, then print.","help":{"concept":"A basic file-reading flow is: open the file, read its contents into a variable, then use that value such as by printing it.","hint_1":"The file must be opened before `.read()` can be used.","hint_2":"After reading into a variable, the last step is showing the result in the output panel."},"tokens":{"t1":"Open the file with `with open(..., \"r\") as file:`","t2":"Read the text with `file.read()`","t3":"Store the result in a variable","t4":"Print the variable"}},"dr-build-path":{"title":"Build a relative path","prompt":"Arrange the tokens to make the relative path to `report.txt` inside the `data` folder.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"data","t2":"/","t3":"report.txt"}},"fb-read-call":{"title":"Complete the read call","prompt":"Fill in the missing method name to read all text from an open file.","hint":"Check every option against the complete behavior described in the question.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"template":"text = file.[blank1]()","choices":["read","write","close","open"]},"fb-open-mode":{"title":"Complete the open mode","prompt":"Fill in the missing mode so the file is opened for reading.","hint":"Focus on the missing concept rather than the exact missing term.","help":{"concept":"The blank should be completed with the term that fits the job being described.","hint_1":"Think about what the missing part needs to do in the statement.","hint_2":"Choose the term that best completes the meaning of the statement."},"template":"with open(\"notes.txt\", \"[blank1]\") as file:","choices":["r","w","a","x"]},"ci-read-and-print":{"title":"Print a file's contents","prompt":"Open `data/message.txt`, read the file's contents, and print the text you find there.\n\nYour output should be exactly:\n`Hello from file reading!`.","hint":"Read the task \"Print a file's contents\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/message.txt\", \"r\") as file:\n # read the file and print its contents\n pass","solutionCode":"with open(\"data/message.txt\", \"r\") as file:\n text = file.read()\n print(text)","sourceChecks":{"0":{"message":"Open data/message.txt to read the file."}}},"ci-first-line":{"title":"Print only the first line","prompt":"Open `data/notes.txt`, read only the first line, and print it without the ending newline character.\n\nYour output should be exactly:\n`Apples`.","hint":"Read the task \"Print only the first line\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/notes.txt\", \"r\") as file:\n # read the first line only\n # print it without the ending newline\n pass","solutionCode":"with open(\"data/notes.txt\", \"r\") as file:\n first = file.readline().rstrip(\"\\n\")\n print(first)","sourceChecks":{"0":{"message":"Open data/notes.txt to read the file."}}},"ci-count-lines":{"title":"Count lines in a text file","prompt":"Open `data/list.txt`, count how many lines are in the file, and print that number.\n\nYour output should be exactly:\n`3`.","hint":"Read the task \"Count lines in a text file\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/list.txt\", \"r\") as file:\n # count the lines and print the number\n pass","solutionCode":"with open(\"data/list.txt\", \"r\") as file:\n lines = file.readlines()\n print(len(lines))","sourceChecks":{"0":{"message":"Open data/list.txt to count the lines."}}},"try-reading-text-files-checkpoint":{"title":"Read a text file","prompt":"Read `data/note.txt` and print its contents without adding extra text.","hint":"Use `with open(\"data/note.txt\") as file:` and `file.read()`.","help":{"concept":"Open the file, read the text, and print exactly what was stored there.","hint_1":"Use `with open(\"data/note.txt\") as file:`.","hint_2":"Call `file.read()` and print the result without adding extra words."},"starterCode":"# Read data/note.txt and print its contents.\n","starterFiles":{"data_note_txt":{"content":"Hello from a file!\n"}},"solutionFiles":{"main_py":{"content":"with open(\"data/note.txt\") as file:\n print(file.read(), end=\"\")\n"},"data_note_txt":{"content":"Hello from a file!\n"}},"sourceChecks":{"0":{"message":"Open data/note.txt instead of typing the file contents."}},"solutionCode":"with open(\"data/note.txt\") as file:\n print(file.read(), end=\"\")\n"},"try-reading-text-files-sketch0":{"title":"Read the whole message file","prompt":"Open `message.txt` in read mode. Read all of its text into a variable named `message`, then print `message`. Print only the text that came from the file. Read the entire file with the `read()` method, store the returned text in a variable named `message`, and print that variable. Do not hard-code the file contents.","hint":"Use `with open(\"message.txt\", \"r\") as file:` and `message = file.read()`.","help":{"concept":"Use `.read()` when you want the complete text file as one string.","hint_1":"Store the result of `file.read()` in `message`.","hint_2":"Print the variable instead of typing the file's contents into your program."},"starterCode":"# Open message.txt in read mode.\n# Read all of its text into message, then print message.\n","starterFiles":{"note_txt":{"content":"Hello from a file\n"},"main_py":{"content":"# Open message.txt in read mode.\n# Read all of its text into message, then print message.\n"},"message_txt":{"content":"Keep learning."}},"solutionFiles":{"main_py":{"content":"with open(\"message.txt\", \"r\") as file:\n message = file.read()\n\nprint(message)\n"},"note_txt":{"content":"Hello from a file\n"},"message_txt":{"content":"Keep learning."}},"sourceChecks":{"0":{"message":"Read from the supplied `message.txt` file."},"1":{"message":"Use `read()` to obtain the file's text."},"2":{"message":"Store the result of `file.read()` in the explicitly requested variable `message`."},"3":{"message":"Print the `message` variable itself after reading the file into it."}},"solutionCode":"with open(\"message.txt\", \"r\") as file:\n message = file.read()\n\nprint(message)\n"},"try-reading-text-files-sketch1":{"title":"Process names one line at a time","prompt":"Open `names.txt` in read mode. Loop directly through the open file with a `for` loop that iterates directly over the opened file object and print each name with surrounding whitespace removed.","hint":"Inside the `with` block, use `for line in file:` and `print(line.strip())`.","help":{"concept":"Iterating over an open file lets you process one line at a time without first reading the whole file into one string.","hint_1":"The loop iterable should be the open variable `file`.","hint_2":"Use `line.strip()` before printing so the stored newline does not create extra blank lines."},"starterCode":"# Open names.txt in read mode.\n# Loop through the open file and print each stripped line.\n","starterFiles":{"names_txt":{"content":" Ava \nMia\n Noah\n"},"main_py":{"content":"# Open names.txt in read mode.\n# Loop through the open file and print each stripped line.\n"}},"solutionFiles":{"main_py":{"content":"with open(\"names.txt\", \"r\") as file:\n for line in file:\n print(line.strip())\n"},"names_txt":{"content":" Ava \nMia\n Noah\n"}},"sourceChecks":{"0":{"message":"Use a `for` loop over `file` as the prompt requests."}},"solutionCode":"with open(\"names.txt\", \"r\") as file:\n for line in file:\n print(line.strip())\n"},"try-reading-text-files-sketch2":{"title":"Read and clean text from a data folder","prompt":"The file `data/city.txt` contains one city name with inconsistent spaces and capitalization. Open that relative path in read mode, read the file text, remove surrounding whitespace, convert it to title case, and print the cleaned city name. Read the text from `data/city.txt`, remove surrounding whitespace with `strip()`, then convert the cleaned city text to title case with `title()`. Do not hard-code the cleaned city name.","hint":"Open `data/city.txt`, then use `.read().strip().title()` on the open file.","help":{"concept":"A relative path can point to a file inside a workspace folder, and the string returned by `.read()` can be processed like any other string.","hint_1":"The path is exactly `data/city.txt`.","hint_2":"Read the text first, then apply `.strip()` and `.title()` before printing."},"starterCode":"# Read data/city.txt in read mode.\n# Clean the file text with strip() and title(), then print it.\n","starterFiles":{"names_txt":{"content":"Ava\nMia\n"},"main_py":{"content":"# Read data/city.txt in read mode.\n# Clean the file text with strip() and title(), then print it.\n"},"data_city_txt":{"content":" seAttle \n"}},"solutionFiles":{"main_py":{"content":"with open(\"data/city.txt\", \"r\") as file:\n city = file.read().strip().title()\n\nprint(city)\n"},"names_txt":{"content":"Ava\nMia\n"},"data_city_txt":{"content":" seAttle \n"}},"sourceChecks":{"0":{"message":"Open the supplied relative path `data/city.txt`."},"1":{"message":"Read the city text from the file with `read()`."},"2":{"message":"Remove surrounding whitespace with `strip()`."},"3":{"message":"Convert the cleaned city text to title case with `title()`."}},"solutionCode":"with open(\"data/city.txt\", \"r\") as file:\n city = file.read().strip().title()\n\nprint(city)\n"},"sc-open-read":{"title":"Open a nested file for reading","prompt":"Which line safely opens `data/story.txt` for reading and gives the open file the name `file`?","hint":"Use a `with` block, the relative path, and read mode `r`.","help":{"concept":"`with open(path, \"r\") as file:` opens an existing text file for reading and closes it automatically when the block ends.","hint_1":"The relative path keeps the folder before the file name: `data/story.txt`.","hint_2":"Read mode is written as `\"r\"`."},"options":{"a":"with open(\"data/story.txt\", \"r\") as file:","b":"with open(\"story.txt/data\", \"w\") as file:","c":"open.read(\"data/story.txt\") as file:","d":"with read(\"data/story.txt\") as file:"}},"sc-read-all":{"title":"What .read() returns","prompt":"What does `file.read()` give you when `file` is an open text file?","hint":"Think about reading the complete contents at once.","help":{"concept":"For a text file, `.read()` returns the remaining file contents as one string.","hint_1":"It does not return one number per line.","hint_2":"Choose the option describing one string containing the file text."},"options":{"a":"One string containing the remaining text","b":"A new file on disk","c":"Only the file name","d":"The number of lines in the file"}},"sc-line-loop":{"title":"Read one line at a time","prompt":"Which pattern processes an open text file one line at a time?","hint":"An open file can be used directly in a `for` loop.","help":{"concept":"`for line in file:` gives the loop one line from the open file at a time.","hint_1":"You do not need `.read()` when you want to iterate through the file directly.","hint_2":"Look for the `for line in file:` pattern."},"options":{"a":"for line in file:","b":"for file in line:","c":"line = file.read()","d":"while file = line:"}},"sc-with-cleanup":{"title":"Why use with open","prompt":"What happens to the file when execution leaves a `with open(...) as file:` block?","hint":"The `with` statement manages the file resource for you.","help":{"concept":"The `with` statement closes the file automatically when the block ends, even though you did not call `file.close()` yourself.","hint_1":"The file is not deleted or rewritten.","hint_2":"The managed file is closed after the block."},"options":{"a":"Python closes the file automatically","b":"Python deletes the file","c":"Python changes the file to write mode","d":"Python keeps the file open forever"}}},"tryIt":{"try_reading_text_files_checkpoint":{"title":"Try it yourself","prompt":"Read `data/note.txt` and print its contents without adding extra text."},"try_reading_text_files_sketch0":{"title":"Try it yourself","prompt":"Open `message.txt` in read mode. Read all of its text into a variable named `message`, then print `message`. Print only the text that came from the file. Read the entire file with the `read()` method, store the returned text in a variable named `message`, and print that variable. Do not hard-code the file contents."},"try_reading_text_files_sketch1":{"title":"Try it yourself","prompt":"Open `names.txt` in read mode. Loop directly through the open file with a `for` loop that iterates directly over the opened file object and print each name with surrounding whitespace removed."},"try_reading_text_files_sketch2":{"title":"Try it yourself","prompt":"The file `data/city.txt` contains one city name with inconsistent spaces and capitalization. Open that relative path in read mode, read the file text, remove surrounding whitespace, convert it to title case, and print the cleaned city name. Read the text from `data/city.txt`, remove surrounding whitespace with `strip()`, then convert the cleaned city text to title case with `title()`. Do not hard-code the cleaned city name."},"allowReveal":true}},"simple-csv-processing":{"label":"Simple CSV Processing","summary":"Read CSV files with `csv.DictReader`, access values by header name, clean and convert row values, and keep valid rows moving through a simple processing loop.","cards":{"sketch0":{"title":"Read CSV rows by column name"},"sketch1":{"title":"Clean and convert CSV values"},"sketch2":{"title":"Process valid rows and reject bad data safely"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-import-csv":{"title":"Why import csv?","prompt":"Why do you write `import csv` before using `csv.DictReader`?","hint":"Think about where `DictReader` comes from.","help":{"concept":"`DictReader` is part of Python's standard library `csv` module, so the module must be imported before you can use `csv.DictReader`.","hint_1":"Look for the choice that says the code is making CSV tools available from a module.","hint_2":"Without the import, Python does not know what `csv` refers to."},"options":{"a":"It makes the `csv` module available so you can use `csv.DictReader`.","b":"It automatically cleans spaces from every CSV value.","c":"It turns every CSV value into an integer.","d":"It creates a new CSV file if one does not exist."}},"sc-dictreader-row-type":{"title":"What does DictReader produce?","prompt":"When you loop through `csv.DictReader(file)`, what is each `row` most like?","hint":"Think about accessing values with column names like `row[\"name\"]`.","help":{"concept":"`csv.DictReader` uses the header row as keys, so each row behaves like a dictionary mapping column names to text values.","hint_1":"If you can use a column name inside square brackets, the row is key-based.","hint_2":"The header labels become keys such as `name` and `score`."},"options":{"a":"A dictionary that maps column names to values","b":"A single integer from the row","c":"A list of file names","d":"A function that cleans the row"}},"mc-clean-score-steps":{"title":"Clean a score value","prompt":"A CSV row has `row[\"score\"] == \" 12 \"`. Which steps correctly prepare it for math? Choose all that apply.","hint":"You need a number, not spaced text.","help":{"concept":"CSV values are read as strings. To use a numeric field in math, remove extra spaces if needed and convert the cleaned text to an integer.","hint_1":"One correct step removes surrounding spaces, and another converts text to a number.","hint_2":"Methods like `.strip()` clean text, while `int(...)` changes the type."},"options":{"a":"Use `.strip()` on the score text","b":"Use `int(...)` on the cleaned score text","c":"Leave it as text and add 1 directly","d":"Use `dict(row)` to turn the score into a number"}},"mc-good-csv-processing":{"title":"Useful CSV processing patterns","prompt":"Which snippets are good beginner patterns for simple CSV processing? Choose all that apply.","hint":"Look for patterns that use the csv module and column names clearly.","help":{"concept":"Good beginner CSV processing uses `import csv`, `csv.DictReader`, and clear access by header names. Printing `dict(row)` is also useful for inspecting a row safely.","hint_1":"One correct option reads rows with `csv.DictReader`, and another prints a full row dictionary for inspection.","hint_2":"Avoid choices that claim CSV values become numbers automatically or that skip importing the module."},"options":{"a":"`import csv` followed by `reader = csv.DictReader(file)`","b":"`print(dict(row))` inside a loop to inspect each row","c":"Using `row[\"score\"]` to access a named column","d":"Assuming `row[\"score\"]` is already an integer without conversion"}},"dr-read-csv-order":{"title":"Order the CSV reading steps","prompt":"Put these steps in the correct order for reading a CSV file with `DictReader` and printing one column.","hint":"Start by making the csv tools available, then open the file, then create the reader.","help":{"concept":"A CSV-reading script usually follows a sequence: import the module, open the file, create a `DictReader`, loop through rows, then access values by column name.","hint_1":"The loop happens after the reader is created.","hint_2":"Accessing `row[\"name\"]` must happen inside the loop, after a row exists."},"tokens":{"t1":"print(row[\"name\"])","t2":": for row in reader","t3":"reader = csv.DictReader(file)","t4":"with open(\"names.csv\") as file","t5":"import csv"}},"dr-clean-row-order":{"title":"Order the row-cleaning steps","prompt":"Arrange these actions in the order that cleans a score and then uses it in math.","hint":"Get the text first, clean it, convert it, then calculate.","help":{"concept":"When cleaning numeric CSV data, first read the text value, then strip spaces, then convert to `int`, and only after that use it in arithmetic.","hint_1":"Arithmetic should happen after conversion to an integer.","hint_2":"`.strip()` belongs before `int(...)`, because it cleans the text that `int` will read."},"tokens":{"t1":"add 1 to the integer score","t2":"convert the cleaned text with `int(...)`","t3":"read `row[\"score\"]`","t4":"remove spaces with `.strip()`"}},"fb-dictreader-name":{"title":"Choose the CSV reader tool","prompt":"Complete the code so rows can be accessed by column name.","hint":"Use the csv tool that creates dictionary-like rows.","help":{"concept":"Choose the csv reader that uses the header row as dictionary keys for every later record.","hint_1":"The missing value is the reader class name after `csv.`.","hint_2":"It is not `reader` or `split`; it is the CSV helper that starts with `Dict`."},"template":"reader = csv.[blank1](file)","choices":["DictReader","reader","split","Writer"]},"fb-strip-choice":{"title":"Choose the cleaning method","prompt":"Fill in the missing method to remove spaces around a CSV value.","hint":"This string method removes spaces from both ends.","help":{"concept":"Choose the string-cleaning method that removes whitespace from both ends before conversion.","hint_1":"The missing method is called on a string like `row[\"name\"]`.","hint_2":"It is the method that turns `\" Ava \"` into `\"Ava\"`."},"template":"clean_name = row[\"name\"].[blank1]()","choices":["strip","append","write","read"]},"ci-print-clean-names":{"title":"Print cleaned names from a CSV file","prompt":"Read `students.csv` with `csv.DictReader`, clean each name as you loop through the rows, and print the cleaned names.\n\nYour output should be exactly:\n`Ava`\n`Ben`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"import csv\n\nwith open(\"students.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n # print the cleaned name\n pass","solutionCode":"import csv\n\nwith open(\"students.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"].strip())","sourceChecks":{"0":{"message":"Strip each CSV name before printing it."}}},"ci-sum-valid-scores":{"title":"Sum valid scores from CSV","prompt":"Read `scores.csv`, clean each score, try to convert it to an integer, and add only the valid numbers to `total`. Print `total` after the loop.\n\nYour output should be exactly:\n`16`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"import csv\n\ntotal = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n # try to convert the cleaned score and add it to total\n pass\n\nprint(total)","solutionCode":"import csv\n\ntotal = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n try:\n total += int(row[\"score\"].strip())\n except ValueError:\n pass\n\nprint(total)","sourceChecks":{"0":{"message":"Use try/except for invalid score values."},"1":{"message":"Convert score text with int()."}}},"ci-write-summary-file":{"title":"Write a CSV summary file","prompt":"Build a short report from `scores.csv`. As you loop, update `valid_rows` and `total_score` for rows with valid integer scores, then write those results to `summary.txt` and print the file contents.\n\nYour output should be exactly:\n`valid_rows: 2`\n`total_score: 16`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"import csv\n\nvalid_rows = 0\ntotal_score = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n # update valid_rows and total_score for rows with valid integer scores\n pass\n\n# write summary.txt, then print its contents","solutionCode":"import csv\n\nvalid_rows = 0\ntotal_score = 0\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n try:\n score = int(row[\"score\"].strip())\n valid_rows += 1\n total_score += score\n except ValueError:\n pass\n\nwith open(\"summary.txt\", \"w\") as file:\n file.write(f\"valid_rows: {valid_rows}\\n\")\n file.write(f\"total_score: {total_score}\\n\")\n\nwith open(\"summary.txt\") as file:\n print(file.read(), end=\"\")","sourceChecks":{"0":{"message":"Use try/except for invalid score values."},"1":{"message":"Write the summary to summary.txt."}}},"try-simple-csv-processing-checkpoint":{"title":"Read the first CSV row","prompt":"Open `scores.csv` with `csv.DictReader`, read the first row, and print the name on one line and the score on the next line.","hint":"Import `csv`, create `csv.DictReader(file)`, then use the first row.","help":{"concept":"This card starts the lesson with a real CSV file instead of a hard-coded string row.","hint_1":"Use `import csv` and `with open(\"scores.csv\") as file:`.","hint_2":"Create `reader = csv.DictReader(file)`, get the first row, and print `row[\"name\"]` and `row[\"score\"]`."},"starterCode":"import csv\n\n# Open scores.csv with csv.DictReader.\n# Print the first row name, then the first row score.\n","solutionCode":"import csv\n\nwith open(\"scores.csv\") as file:\n reader = csv.DictReader(file)\n row = next(reader)\n print(row[\"name\"])\n print(row[\"score\"])\n","sourceChecks":{"0":{"message":"Use csv.DictReader to read scores.csv."},"1":{"message":"Open scores.csv for this step."}}},"try-simple-csv-processing-sketch0":{"title":"Read rows by header name","prompt":"Read a CSV filename from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Open that file in read mode, create a `csv.DictReader` created for the opened file, loop through every row, and print each row as `name:score` using `row[\"name\"]` and `row[\"score\"]`. The workspace provides `data/class_a.csv` and `data/class_b.csv`.","hint":"Use the CSV header names instead of splitting each line manually.","help":{"concept":"`csv.DictReader` turns each data row into a dictionary-like object whose keys come from the header row.","hint_1":"Create `reader = csv.DictReader(file)` inside the open-file block.","hint_2":"Use a `for row in reader:` loop and access both named columns from `row`."},"starterCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Open path in read mode with csv.DictReader.\n# Loop through every row and print name:score using the named columns.\n","solutionCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use a `for` loop as the prompt requests."},"2":{"message":"Use the explicitly requested dictionary field `name`."},"3":{"message":"Use the explicitly requested dictionary field `score`."}},"starterFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Open path in read mode with csv.DictReader.\n# Loop through every row and print name:score using the named columns.\n"},"data_class_a_csv":{"content":"name,score\nAva,92\nBen,85\n"},"data_class_b_csv":{"content":"name,score\nMia,78\nNoah,88\nLiam,91\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \":\" + row[\"score\"])\n"},"data_class_a_csv":{"content":"name,score\nAva,92\nBen,85\n"},"data_class_b_csv":{"content":"name,score\nMia,78\nNoah,88\nLiam,91\n"}}},"try-simple-csv-processing-sketch1":{"title":"Clean and convert CSV fields","prompt":"Read a CSV filename from input. Open `data/<filename>` with `csv.DictReader`. For every row, clean the name with whitespace trimming followed by title-case normalization, clean and convert the score with integer conversion of the `score` field after removing its surrounding whitespace, then print `Name:score`. The supplied files contain valid numeric score text with inconsistent whitespace and capitalization.","hint":"CSV field values are strings, so clean the text before converting the score.","help":{"concept":"This step combines named-column access with the cleaning and integer-conversion skills you already know.","hint_1":"Store a cleaned `name` and numeric `score` inside the row loop.","hint_2":"Do not hard-code the displayed names or scores; use the values from each CSV row."},"starterCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Read every row with csv.DictReader.\n# Clean the name with strip().title(), convert the cleaned score with int(),\n# and print Name:score for each row.\n","solutionCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score = int(row[\"score\"].strip())\n print(name + \":\" + str(score))\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use the explicitly requested dictionary field `score`."},"2":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"3":{"message":"Use `title()` because that method is explicitly required by the prompt."},"4":{"message":"Call `int(...)` because that function call is explicitly required by the prompt."}},"starterFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\n# Read every row with csv.DictReader.\n# Clean the name with strip().title(), convert the cleaned score with int(),\n# and print Name:score for each row.\n"},"data_clean_a_csv":{"content":"name,score\n aVA , 92 \n ben lee , 85\n"},"data_clean_b_csv":{"content":"name,score\n mIA , 70 \n NOAH , 100 \n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score = int(row[\"score\"].strip())\n print(name + \":\" + str(score))\n"},"data_clean_a_csv":{"content":"name,score\n aVA , 92 \n ben lee , 85\n"},"data_clean_b_csv":{"content":"name,score\n mIA , 70 \n NOAH , 100 \n"}}},"try-simple-csv-processing-sketch2":{"title":"Summarize only valid CSV rows","prompt":"Read a CSV filename from input and process `data/<filename>` with `csv.DictReader`. Clean each name and score field. Count and sum only rows whose cleaned name is not empty and whose score converts to an integer from 0 through 100. After the loop, print exactly `valid_rows: <count>` and `total_score: <sum>`. Invalid rows should not stop later rows from being processed.","hint":"Apply the 7.5 validation rules inside the CSV row loop.","help":{"concept":"A CSV row is accepted only after the name, conversion, and range checks all succeed.","hint_1":"Catch exactly `ValueError` and set `score = None` so invalid numeric text has an explicit rejection value.","hint_2":"Increment `valid_rows` and `total_score` only inside the valid 0-through-100 branch."},"starterCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\n# Read every CSV row.\n# Clean the name and score text.\n# Count and sum only rows with a non-empty name and an integer score from 0..100.\n# Print valid_rows and total_score after the loop.\n","solutionCode":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name != \"\":\n try:\n score = int(score_text)\n except ValueError:\n score = None\n\n if score is not None and 0 <= score <= 100:\n valid_rows += 1\n total_score += score\n\nprint(\"valid_rows: \" + str(valid_rows))\nprint(\"total_score: \" + str(total_score))\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Loop through the CSV rows instead of hard-coding the total."},"2":{"message":"Convert the score text with int()."},"3":{"message":"Add each numeric score into total."}},"starterFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\n# Read every CSV row.\n# Clean the name and score text.\n# Count and sum only rows with a non-empty name and an integer score from 0..100.\n# Print valid_rows and total_score after the loop.\n"},"data_mixed_a_csv":{"content":"name,score\n Ava ,92\n ,75\nLeo,ten\nMia,105\nNoah,80\n"},"data_mixed_b_csv":{"content":"name,score\n kai ,0\nLena,100\nOmar,-2\nIvy,55\nNia,oops\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nfilename = input().strip()\npath = \"data/\" + filename\nvalid_rows = 0\ntotal_score = 0\n\nwith open(path, \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n name = row[\"name\"].strip().title()\n score_text = row[\"score\"].strip()\n\n if name != \"\":\n try:\n score = int(score_text)\n except ValueError:\n score = None\n\n if score is not None and 0 <= score <= 100:\n valid_rows += 1\n total_score += score\n\nprint(\"valid_rows: \" + str(valid_rows))\nprint(\"total_score: \" + str(total_score))\n"},"data_mixed_a_csv":{"content":"name,score\n Ava ,92\n ,75\nLeo,ten\nMia,105\nNoah,80\n"},"data_mixed_b_csv":{"content":"name,score\n kai ,0\nLena,100\nOmar,-2\nIvy,55\nNia,oops\n"}}},"sc-dictreader-purpose":{"title":"Why use DictReader?","prompt":"What is the main beginner benefit of `csv.DictReader(file)` when the CSV has a header row such as `name,score`?","hint":"Think about how you access `row[\"name\"]`.","help":{"concept":"`csv.DictReader` uses the header row as keys, so later rows can be accessed by meaningful column names.","hint_1":"The header labels become names such as `name` and `score`.","hint_2":"Choose the answer about dictionary-like rows and named columns."},"options":{"a":"Each row can be accessed with keys such as `row[\"name\"]` and `row[\"score\"]`","b":"Every value is automatically converted to an integer","c":"The CSV file is rewritten with cleaner spacing","d":"The header row is deleted from disk"}},"sc-csv-value-type":{"title":"CSV values start as text","prompt":"If a CSV row contains `Ava,92`, what kind of value is `row[\"score\"]` when it first comes from `csv.DictReader`?","hint":"Reading CSV data does not automatically perform numeric conversion.","help":{"concept":"`csv.DictReader` reads field values as strings. Numeric-looking text must still be converted before numeric calculations.","hint_1":"The characters `92` came from a text file.","hint_2":"Choose the string value rather than the integer value."},"options":{"a":"The string `\"92\"`","b":"The integer `92`","c":"The float `92.0`","d":"A dictionary containing only the score"}},"sc-clean-convert-order":{"title":"Clean before numeric conversion","prompt":"A CSV score field is `\" 92 \"`. Which expression correctly removes surrounding spaces and converts it to an integer?","hint":"Clean the string first, then pass the cleaned text to `int(...)`.","help":{"concept":"CSV values are strings, so a common numeric-field pattern is `int(row[\"score\"].strip())`.","hint_1":"`.strip()` removes surrounding whitespace.","hint_2":"`int(...)` performs the numeric conversion after cleaning."},"options":{"a":"int(row[\"score\"].strip())","b":"row[\"score\"].int().strip()","c":"row[\"score\"] + 1","d":"csv.int(row[\"score\"])"}},"sc-bad-row-policy":{"title":"Reject one bad row without stopping later rows","prompt":"While processing many CSV rows, one cleaned score contains `\"oops\"`. What beginner pattern lets the program reject that row and continue processing later rows?","hint":"Use the specific conversion exception from the previous topics.","help":{"concept":"Catch `ValueError` around the integer conversion for that row, then continue the surrounding row-processing logic.","hint_1":"The problem is invalid integer text, not a missing file.","hint_2":"Choose the pattern that handles `ValueError` rather than crashing the whole CSV loop."},"options":{"a":"Use `try` around `int(...)` and catch `ValueError` for that row","b":"Assume every score is already valid","c":"Catch `FileNotFoundError` around the integer conversion","d":"Convert every bad score to 0 automatically"}}},"tryIt":{"try_simple_csv_processing_checkpoint":{"title":"Try it yourself","prompt":"Open `scores.csv` with `csv.DictReader`, read the first row, and print the name on one line and the score on the next line."},"try_simple_csv_processing_sketch0":{"title":"Try it yourself","prompt":"Read a CSV filename from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Open that file in read mode, create a `csv.DictReader` created for the opened file, loop through every row, and print each row as `name:score` using `row[\"name\"]` and `row[\"score\"]`. The workspace provides `data/class_a.csv` and `data/class_b.csv`."},"try_simple_csv_processing_sketch1":{"title":"Try it yourself","prompt":"Read a CSV filename from input. Open `data/<filename>` with `csv.DictReader`. For every row, clean the name with whitespace trimming followed by title-case normalization, clean and convert the score with integer conversion of the `score` field after removing its surrounding whitespace, then print `Name:score`. The supplied files contain valid numeric score text with inconsistent whitespace and capitalization."},"try_simple_csv_processing_sketch2":{"title":"Try it yourself","prompt":"Process only valid CSV rows and summarize the accepted scores."},"allowReveal":true}},"try-except-basics":{"label":"Try/Except Basics","summary":"Protect an operation that may fail with `try`, catch the specific expected exception, and keep the program usable with a clear fallback instead of a crash.","cards":{"sketch0":{"title":"Catch ValueError from a risky conversion"},"sketch1":{"title":"Catch FileNotFoundError when opening a path"},"sketch2":{"title":"Continue after a handled exception"},"quiz":{"title":"Check your understanding"}},"quiz":{"q1":{"title":"What happens after a caught conversion error?","prompt":"A program runs this pattern:\n\n```python\ntry:\n number = int(text)\nexcept ValueError:\n print(\"Bad number\")\n```\n\nIf `text` is `\"cat\"`, what happens?","hint":"Think about what `int()` does with text that is not a valid whole number.","help":{"concept":"`except ValueError` handles failures from `int()` when text cannot be converted to an integer.","hint_1":"`int(\"cat\")` cannot produce a number, so Python raises a `ValueError`.","hint_2":"Because that specific error is caught, the program runs the `except` block instead of stopping immediately."},"options":{"a":"The `except` block runs and prints `Bad number`","b":"The `try` block prints the converted number","c":"Python ignores the bad text and uses 0","d":"The program always stops before reaching `except`"}},"q2":{"title":"Which error fits int conversion?","prompt":"Which exception type should you catch when `int(user_text)` might fail because the text is not a valid integer?","hint":"Work through the operation in Python terms, then select the matching option.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"NameError","b":"ValueError","c":"IndexError","d":"SyntaxError"}},"q3":{"title":"Why use try/except here?","prompt":"Choose all true reasons to use `try/except` around `int(text)` when cleaning messy input.","hint":"Look for benefits related to handling bad numeric text safely.","help":{"concept":"`try/except` is useful when some values may be invalid and you want the program to respond safely instead of crashing.","hint_1":"Think about what happens when one item is bad in a larger set of inputs.","hint_2":"Correct choices should mention graceful handling and continued program flow, not guaranteed conversion success."},"options":{"a":"It lets the program handle invalid numeric text without crashing immediately","b":"It can show a fallback message when conversion fails","c":"It guarantees every string will become an integer","d":"It can help a loop continue processing later values after one bad value"}},"q4":{"title":"Which inputs would trigger ValueError?","prompt":"Choose all values that would raise `ValueError` in `int(value)`.","hint":"Pick the strings that are not valid whole-number text.","help":{"concept":"`int()` accepts strings like `\"12\"` or `\"-3\"`, but rejects text with letters or decimal points in string form for plain integer conversion.","hint_1":"A minus sign with digits is still a valid integer string.","hint_2":"Look for values containing letters or a decimal point as text."},"options":{"a":"\"18\"","b":"\"blue\"","c":"\"4.5\"","d":"\"-2\""}},"q5":{"title":"Order of execution when conversion fails","prompt":"Put these steps in the order they happen when `int(text)` raises `ValueError` inside a `try/except` block.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"Python enters the `try` block","t2":"`int(text)` raises `ValueError`","t3":"The rest of the `try` block is skipped","t4":"The matching `except` block runs"}},"q6":{"title":"Build a basic try/except pattern","prompt":"Arrange these code pieces into a correct basic pattern that converts input text to an integer and handles bad input.","hint":"Arrange the code pieces in the order Python should run them.","help":{"concept":"The pieces should form valid Python code in the order it should run.","hint_1":"Start with the line that sets up the Python action.","hint_2":"Place lines that depend on earlier values after those values exist."},"tokens":{"t1":"try:","t2":"number = int(text)","t3":"print(number)","t4":"except ValueError:","t5":"print(\"Invalid input\")"}},"q7":{"title":"Name the catching keyword","prompt":"Complete the code keyword that handles the error after `try`.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"try:\n number = int(text)\n[blank1] ValueError:\n print(\"Bad input\")","choices":["except","return","while","import"]},"q8":{"title":"Choose the risky conversion","prompt":"Fill in the expression that can raise `ValueError` when the text is not a valid integer.","hint":"Use the built-in conversion from text to integer.","help":{"concept":"The risky step in this pattern is converting text with `int(...)`, because some strings are not valid integers.","hint_1":"The missing code should attempt to turn `user_text` into a whole number.","hint_2":"Choose the expression that calls Python's integer conversion function on the variable."},"template":"try:\n number = [blank1]\n print(number)\nexcept ValueError:\n print(\"Invalid\")","choices":["int(user_text)","print(user_text)","len(user_text)","str(user_text)"]},"q9":{"title":"Catch a bad integer input","prompt":"A number scanner might receive invalid text. Convert the input inside a `try` block, then print either the formatted number or an invalid message.\n\nFor example, if the input is `27`, your program should print:\n`Number: 27`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"text = input()\n\n# Convert the text to an integer inside try.\n# Print either the converted result or an invalid message.","solutionCode":"text = input()\n\ntry:\n number = int(text)\n print(f\"Number: {number}\")\nexcept ValueError:\n print(\"Invalid number\")","sourceChecks":{"0":{"message":"Use a try block for the conversion."},"1":{"message":"Convert the text with int()."}}},"q10":{"title":"Add two inputs safely","prompt":"Two score entries arrive as text. Convert both values inside `try`, then print the sum or an invalid message if either value cannot be turned into an integer.\n\nFor example, if the inputs are `8` and `5`, your program should print:\n`Sum: 13`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"first_text = input()\nsecond_text = input()\n\n# Convert both values inside try.\n# Print the sum or an invalid message.","solutionCode":"first_text = input()\nsecond_text = input()\n\ntry:\n first_number = int(first_text)\n second_number = int(second_text)\n print(f\"Sum: {first_number + second_number}\")\nexcept ValueError:\n print(\"Invalid input\")","sourceChecks":{"0":{"message":"Use a try block for the conversion."},"1":{"message":"Convert the text with int()."}}},"q11":{"title":"Count valid numbers","prompt":"A comma-separated list may contain bad entries. Loop through each part, try to convert it to `int`, count only the valid integers, and print the final count.\n\nFor example, if the input is `3,7,bad,10`, your program should print:\n`Valid count: 3`.","hint":"Read the code or question carefully and choose the option that creates the exact behavior the prompt asks for.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"parts = input().split(\",\")\nvalid_count = 0\n\n# Loop through each part.\n# Try to convert each one to int.\n# Count only the valid integers.\n# Print the final count.","solutionCode":"parts = input().split(\",\")\nvalid_count = 0\n\nfor part in parts:\n try:\n int(part)\n valid_count += 1\n except ValueError:\n pass\n\nprint(f\"Valid count: {valid_count}\")","sourceChecks":{"0":{"message":"Loop through each part."},"1":{"message":"Use try/except around the int conversion."},"2":{"message":"Convert each value with int()."}}},"try-try-except-basics-checkpoint":{"title":"Handle a bad number","prompt":"Read input and try to convert it to an integer. Print `Valid` if it works, otherwise print `Invalid`.","hint":"Use `try`, `except ValueError`.","help":{"concept":"A `try/except` block handles errors without crashing the program.","hint_1":"Use `try`, `except ValueError`.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"text = input()\n\n# Print Valid for an integer, otherwise Invalid.\n","solutionCode":"text = input()\ntry:\n int(text)\n print(\"Valid\")\nexcept ValueError:\n print(\"Invalid\")\n","sourceChecks":{"0":{"message":"Use a try block for the conversion."},"1":{"message":"Convert the text with int()."}}},"try-try-except-basics-sketch0":{"title":"Handle an invalid integer","prompt":"Read one line of text. Inside `try`, convert it with `int(text)` and print `Number: <value>`. Catch exactly `ValueError` and print `Invalid number` when conversion fails.","hint":"The conversion belongs inside `try`, and the handler should name `ValueError`.","help":{"concept":"`int(text)` can raise `ValueError`; catching that specific exception lets the program show a clear fallback instead of crashing.","hint_1":"Keep `number = int(text)` inside the `try` block.","hint_2":"Use `except ValueError:` followed by `print(\"Invalid number\")`."},"starterCode":"text = input().strip()\n\n# Convert text with int(...) inside try.\n# Print Number: <value> or Invalid number.\n","solutionCode":"text = input().strip()\n\ntry:\n number = int(text)\n print(\"Number: \" + str(number))\nexcept ValueError:\n print(\"Invalid number\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Call `int(...)` because that function call is explicitly required by the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"starterFiles":{"main_py":{"content":"text = input().strip()\n\n# Convert text with int(...) inside try.\n# Print Number: <value> or Invalid number.\n"}},"solutionFiles":{"main_py":{"content":"text = input().strip()\n\ntry:\n number = int(text)\n print(\"Number: \" + str(number))\nexcept ValueError:\n print(\"Invalid number\")\n"}}},"try-try-except-basics-sketch1":{"title":"Handle a missing data file","prompt":"Read a file name from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Try to open that path in read mode and print its stripped text. Catch exactly `FileNotFoundError` and print `Missing file` when the selected file does not exist. The workspace provides `data/note.txt`.","hint":"The risky operation is opening the selected path for reading.","help":{"concept":"A missing read path raises `FileNotFoundError`, which is different from the `ValueError` raised by a bad integer conversion.","hint_1":"Keep `with open(path, \"r\") as file:` inside `try`.","hint_2":"Use `except FileNotFoundError:` for the missing-file fallback."},"starterCode":"filename = input().strip()\npath = \"data/\" + filename\n\n# Try to open path in read mode and print its stripped text.\n# If the file is missing, print Missing file.\n","solutionCode":"filename = input().strip()\npath = \"data/\" + filename\n\ntry:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\nexcept FileNotFoundError:\n print(\"Missing file\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Convert the text with int()."}},"starterFiles":{"main_py":{"content":"filename = input().strip()\npath = \"data/\" + filename\n\n# Try to open path in read mode and print its stripped text.\n# If the file is missing, print Missing file.\n"},"data_note_txt":{"content":"Study exceptions carefully.\n"}},"solutionFiles":{"main_py":{"content":"filename = input().strip()\npath = \"data/\" + filename\n\ntry:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\nexcept FileNotFoundError:\n print(\"Missing file\")\n"},"data_note_txt":{"content":"Study exceptions carefully.\n"}}},"try-try-except-basics-sketch2":{"title":"Continue after one missing file","prompt":"Read two file names. Loop through `[first, second]`. For each name, try to open `data/<filename>` and print the stripped text. If that file is missing, catch exactly `FileNotFoundError`, print `Missing: <filename>`, and let the loop continue to the next name. The workspace provides `data/alpha.txt` and `data/beta.txt`.","hint":"Put the `try/except` inside the loop so one missing file does not stop the second attempt.","help":{"concept":"A handled exception ends that iteration's risky work, then normal loop execution continues with the next item.","hint_1":"Build `path = \"data/\" + filename` inside the loop.","hint_2":"Catch `FileNotFoundError` and print the missing filename instead of using `pass`."},"starterCode":"first = input().strip()\nsecond = input().strip()\n\n# Loop through [first, second].\n# For each filename, open data/<filename> and print its stripped text.\n# If that file is missing, print Missing: <filename> and continue.\n","solutionCode":"first = input().strip()\nsecond = input().strip()\n\nfor filename in [first, second]:\n path = \"data/\" + filename\n try:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\n except FileNotFoundError:\n print(\"Missing: \" + filename)\n","sourceChecks":{"0":{"message":"Use a `for` loop as the prompt requests."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Convert each value with int()."}},"starterFiles":{"main_py":{"content":"first = input().strip()\nsecond = input().strip()\n\n# Loop through [first, second].\n# For each filename, open data/<filename> and print its stripped text.\n# If that file is missing, print Missing: <filename> and continue.\n"},"data_alpha_txt":{"content":"Alpha file\n"},"data_beta_txt":{"content":"Beta file\n"}},"solutionFiles":{"main_py":{"content":"first = input().strip()\nsecond = input().strip()\n\nfor filename in [first, second]:\n path = \"data/\" + filename\n try:\n with open(path, \"r\") as file:\n text = file.read().strip()\n print(text)\n except FileNotFoundError:\n print(\"Missing: \" + filename)\n"},"data_alpha_txt":{"content":"Alpha file\n"},"data_beta_txt":{"content":"Beta file\n"}}},"sc-value-error":{"title":"Match the conversion error","prompt":"Which exception should handle `int(text)` when `text` might contain something like `\"apple\"`?","hint":"An invalid value is being passed to a valid conversion function.","help":{"concept":"`int(...)` raises `ValueError` when the text cannot represent a whole number.","hint_1":"The function name `int` exists, so this is not a `NameError`.","hint_2":"Choose the exception for a value that cannot be converted."},"options":{"a":"ValueError","b":"FileNotFoundError","c":"NameError","d":"IndexError"}},"sc-file-not-found":{"title":"Match the missing-file error","prompt":"Which exception should handle `open(\"data/missing.txt\", \"r\")` when the file does not exist?","hint":"The path points to a file that Python cannot find.","help":{"concept":"Opening a missing path for reading raises `FileNotFoundError`.","hint_1":"This is a file-location problem, not an integer-conversion problem.","hint_2":"Choose the exception whose name describes a missing file."},"options":{"a":"FileNotFoundError","b":"ValueError","c":"TypeError","d":"IndexError"}},"sc-matching-handler":{"title":"What happens after an exception is caught","prompt":"When code inside `try` raises a `ValueError` and the program has `except ValueError:`, what happens next?","hint":"Python stops the remaining statements in that `try` block and jumps to the matching handler.","help":{"concept":"A matching `except` block handles the raised exception; statements after the failing line inside `try` are skipped.","hint_1":"Python does not continue the rest of the `try` block after the exception.","hint_2":"Choose the option where the matching `except` block runs."},"options":{"a":"Python runs the matching `except ValueError` block","b":"Python ignores the error and continues the next line inside `try`","c":"Python changes the bad value to 0","d":"Python always stops before checking `except`"}},"sc-specific-exception":{"title":"Why catch a specific exception","prompt":"Why is `except ValueError:` better here than a broad bare `except:` when the risky operation is `int(text)`?","hint":"Handle the error you expect instead of hiding unrelated problems.","help":{"concept":"Catching the specific expected exception makes the program's intent clearer and avoids silently swallowing unrelated bugs.","hint_1":"The known risk is an invalid integer value.","hint_2":"Choose the answer about handling that known error while leaving unrelated errors visible."},"options":{"a":"It handles the expected conversion error without hiding every unrelated exception","b":"It guarantees every string becomes an integer","c":"It makes `try` unnecessary","d":"It turns all exceptions into `ValueError`"}}},"tryIt":{"try_try_except_basics_checkpoint":{"title":"Try it yourself","prompt":"Read input and try to convert it to an integer. Print `Valid` if it works, otherwise print `Invalid`."},"try_try_except_basics_sketch0":{"title":"Try it yourself","prompt":"Convert user input safely with `except ValueError`."},"try_try_except_basics_sketch1":{"title":"Try it yourself","prompt":"Read a file name from input and build a path stored in `path` by concatenating the `data/` prefix with `filename`. Try to open that path in read mode and print its stripped text. Catch exactly `FileNotFoundError` and print `Missing file` when the selected file does not exist. The workspace provides `data/note.txt`."},"try_try_except_basics_sketch2":{"title":"Try it yourself","prompt":"Keep processing a second file after the first filename is missing."},"allowReveal":true}},"validating-and-cleaning-input":{"label":"Validating and Cleaning Input","summary":"Clean raw text before using it, detect missing values after cleaning, validate integer ranges safely, and combine those rules in a reusable function.","cards":{"sketch0":{"title":"Clean text before validating it"},"sketch1":{"title":"Missing, invalid, and out-of-range values"},"sketch2":{"title":"Combine cleaning rules in a function"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-valid-row":{"title":"Which row is valid after cleaning?","prompt":"A program strips spaces from both fields, then requires a non-empty name and an age that can be converted with `int()`. Which row would be accepted?","hint":"Look for a row where spaces can be removed and the age text still becomes a whole number.","help":{"concept":"A row is valid only if cleaning with `strip()` leaves a real name and an age string that `int()` can convert.","hint_1":"Check each option after removing leading and trailing spaces from both values.","hint_2":"Reject rows with an empty cleaned name or an age like a word instead of digits."},"options":{"a":"[' Ava ', ' 12 ']","b":"[' ', '9']","c":"['Leo', 'ten']","d":"['Mia', '4.5']"}},"sc-except-flow":{"title":"What does except catch here?","prompt":"In a `try`/`except ValueError` block, what kind of problem is the `except` meant to handle during `int(age_text)`?","hint":"Think about what happens when text cannot be turned into an integer.","help":{"concept":"`ValueError` is raised when a conversion function like `int()` receives a value of the right general type but with unusable content.","hint_1":"`int()` works for strings like `'7'`, but not for strings that contain words or decimal text in this beginner context.","hint_2":"The problem is not a missing variable name or a syntax mistake in the code editor; it is bad input content during conversion."},"options":{"a":"A text value such as 'ten' that cannot be converted to an integer","b":"A missing `print()` statement","c":"A list index being too large","d":"A file path always being relative"}},"mc-clean-steps":{"title":"Useful cleaning steps","prompt":"Choose all steps that help clean a text row before validation.","hint":"Think about operations that remove formatting noise or standardize text values.","help":{"concept":"Cleaning prepares raw text for validation by removing extra spaces or making formatting more consistent before rule checks happen.","hint_1":"Methods like `strip()` and case normalization help; actions that only display data do not clean it.","hint_2":"Pick the options that change messy input into a more consistent form before checking whether it is valid."},"options":{"a":"Use `strip()` to remove extra spaces around a value","b":"Convert a name like 'aVA' to a consistent case such as title case","c":"Print the row without changing it","d":"Keep all spaces exactly as they were so validation sees the mess"}},"mc-reject-row":{"title":"Which rows should be rejected?","prompt":"A cleaned row is valid only when the name is not empty and the score is an integer from 0 to 100. Choose all rows that should be rejected.","hint":"Check each row after trimming spaces, then test both rules.","help":{"concept":"Validation can involve more than one rule: presence, type conversion, and allowed numeric range.","hint_1":"A row fails if the cleaned name is empty, if the score cannot become an integer, or if the integer is outside 0 to 100.","hint_2":"Look closely at the rows with only spaces for the name, word-based scores, and numbers above the allowed maximum."},"options":{"a":"['Ava', '90']","b":"[' ', '75']","c":"['Leo', 'ten']","d":"['Mia', '105']"}},"dr-clean-order":{"title":"Order the cleaning process","prompt":"Put these steps in a sensible order for cleaning and validating one text value that should become an integer.","hint":"Clean formatting before conversion, and only use the number after conversion succeeds.","help":{"concept":"A reliable cleaning flow removes extra spaces first, then attempts conversion, then uses the converted value for later checks.","hint_1":"If you try `int()` before removing spaces and checking the raw text, your code is harder to reason about.","hint_2":"Start with the original text, clean it, convert it, then continue with numeric validation."},"tokens":{"t1":"Read the text value","t2":"Remove extra spaces with `strip()`","t3":"Convert the cleaned text with `int()`","t4":"Use the integer in later checks"}},"dr-try-except-order":{"title":"Order the try/except flow","prompt":"Arrange these parts to show the usual flow when converting cleaned text to an integer safely.","hint":"The risky conversion belongs inside `try`, and the error handling comes after it.","help":{"concept":"`try` contains code that may fail, while `except` handles a specific error if that failure happens.","hint_1":"Place the conversion attempt after entering `try`, and place the fallback action inside `except ValueError`.","hint_2":"The successful path uses the converted number before the error-handling path appears."},"tokens":{"t1":"Start `try:`","t2":"Attempt `age = int(age_text)`","t3":"Use `age` if conversion worked","t4":"Handle bad input in `except ValueError:`"}},"fb-strip-name":{"title":"Fill the cleaning method","prompt":"Complete the code so it removes extra spaces around the name.","hint":"Use the string method that trims spaces from both ends.","help":{"concept":"Choose the string method that removes whitespace from both ends without changing internal spaces.","hint_1":"The missing value is a method name used like `name.[blank1]()` in Python.","hint_2":"It is the method that turns `' Ava '` into `'Ava'` without changing letters in the middle."},"template":"clean_name = name.[blank1]()","choices":["split","strip","append","write"]},"fb-empty-check":{"title":"Fill the missing comparison","prompt":"Complete the condition so it detects a missing cleaned value.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"if cleaned_name == [blank1]:","choices":["0","None","\"\"","False"]},"ci-clean-name":{"title":"Write a name cleaning function","prompt":"Write `clean_name(text)` so it returns a cleaned version of the name text.","hint":"Read the task \"Write a name cleaning function\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def clean_name(text):\n # return the cleaned name\n pass","solutionCode":"def clean_name(text):\n cleaned = text.strip()\n return cleaned.title()"},"ci-parse-age":{"title":"Parse an age safely","prompt":"Write `parse_age(text)` so it returns an `int` for valid age text and `None` when the text cannot be used as an age.","hint":"Read the task \"Parse an age safely\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def parse_age(text):\n # return an int or None\n pass","solutionCode":"def parse_age(text):\n cleaned = text.strip()\n try:\n return int(cleaned)\n except ValueError:\n return None"},"ci-clean-row":{"title":"Validate and clean one row","prompt":"Write `clean_row(row)` for rows shaped like `[name_text, score_text]`. Return a cleaned dictionary when both values are valid, or `None` when the row should be rejected.","hint":"Read the task \"Validate and clean one row\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"def clean_row(row):\n # row looks like [name_text, score_text]\n # return a cleaned dictionary or None\n pass","solutionCode":"def clean_row(row):\n name = row[0].strip()\n score_text = row[1].strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(score_text)\n except ValueError:\n return None\n\n return {\"name\": name.title(), \"score\": score}"},"try-validating-and-cleaning-input-checkpoint":{"title":"Clean and validate a name","prompt":"Read a name. Strip spaces and title-case it. If the cleaned name is empty, print `Missing`; otherwise print the cleaned name.","hint":"Use `.strip()` before checking whether the value is empty.","help":{"concept":"Cleaning input before validation helps programs handle messy text.","hint_1":"Use `.strip()` before checking whether the value is empty.","hint_2":"Run your code and compare the output with the expected result."},"starterCode":"name = input()\n\n# Clean and validate the name.\n","solutionCode":"name = input().strip().title()\nif name:\n print(name)\nelse:\n print(\"Missing\")\n","sourceChecks":{"0":{"message":"Strip whitespace from the name."},"1":{"message":"Title-case the cleaned name."}}},"try-validating-and-cleaning-input-sketch0":{"title":"Clean and validate a required name","prompt":"Read a name. Store a cleaned version of `raw_name` with surrounding whitespace removed and title case applied in `cleaned_name`. If an explicit comparison between `cleaned_name` and the empty string, print `Missing`; otherwise print the cleaned name.","hint":"Clean the text before checking whether anything meaningful remains.","help":{"concept":"A spaces-only required field becomes `\"\"` after `strip()`, so validation should check the cleaned value rather than the raw input.","hint_1":"Assign the cleaned result to `cleaned_name`.","hint_2":"Use the explicit comparison `cleaned_name == \"\"` for the missing-value branch."},"starterCode":"raw_name = input()\n\n# Clean raw_name with strip() and title().\n# Print Missing if the cleaned name is \"\"; otherwise print the cleaned name.\n","solutionCode":"raw_name = input()\ncleaned_name = raw_name.strip().title()\n\nif cleaned_name == \"\":\n print(\"Missing\")\nelse:\n print(cleaned_name)\n","sourceChecks":{"0":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"starterFiles":{"main_py":{"content":"raw_name = input()\n\n# Clean raw_name with strip() and title().\n# Print Missing if the cleaned name is \"\"; otherwise print the cleaned name.\n"}},"solutionFiles":{"main_py":{"content":"raw_name = input()\ncleaned_name = raw_name.strip().title()\n\nif cleaned_name == \"\":\n print(\"Missing\")\nelse:\n print(cleaned_name)\n"}}},"try-validating-and-cleaning-input-sketch1":{"title":"Validate integer text and range","prompt":"Read a score, remove surrounding whitespace, and safely convert it with `int()`. Print `Valid score` only when the integer is from 0 through 100. Print `Invalid score` when conversion raises `ValueError` or when the integer is outside that range.","hint":"A valid integer conversion and a valid numeric range are two separate checks.","help":{"concept":"Use `try/except ValueError` for bad integer text, then apply the 0-through-100 range rule to successfully converted values.","hint_1":"Keep `score = int(score_text)` inside `try`.","hint_2":"Check the inclusive range with `0 <= score <= 100`."},"starterCode":"score_text = input()\n\n# Strip score_text, convert it safely with int(),\n# and print Valid score only for integers from 0 through 100.\n# Print Invalid score for bad integer text or an out-of-range number.\n","solutionCode":"score_text = input().strip()\n\ntry:\n score = int(score_text)\n if 0 <= score <= 100:\n print(\"Valid score\")\n else:\n print(\"Invalid score\")\nexcept ValueError:\n print(\"Invalid score\")\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Check that the score is within 0 to 100."}},"starterFiles":{"main_py":{"content":"score_text = input()\n\n# Strip score_text, convert it safely with int(),\n# and print Valid score only for integers from 0 through 100.\n# Print Invalid score for bad integer text or an out-of-range number.\n"}},"solutionFiles":{"main_py":{"content":"score_text = input().strip()\n\ntry:\n score = int(score_text)\n if 0 <= score <= 100:\n print(\"Valid score\")\n else:\n print(\"Invalid score\")\nexcept ValueError:\n print(\"Invalid score\")\n"}}},"try-validating-and-cleaning-input-sketch2":{"title":"Clean and validate a record","prompt":"Complete `clean_record(name_text, score_text)`. Clean the name with whitespace trimming followed by title-case normalization and the score text with `strip()`. Return `None` for an empty cleaned name, invalid integer score text, or a score outside 0 through 100. Otherwise return `{\"name\": name, \"score\": score}`. The caller should print `Rejected` for `None`; otherwise print `Name:score`.","hint":"Apply the rules in order: clean, check the required name, convert safely, check the range, then return the cleaned dictionary.","help":{"concept":"A reusable cleaning function can return `None` for rejected input and structured cleaned data for accepted input.","hint_1":"Use `name == \"\"` for the missing-name rule and `except ValueError:` for bad score text.","hint_2":"Return the dictionary only after every rejection condition has been passed."},"starterCode":"def clean_record(name_text, score_text):\n # Return {\"name\": cleaned_name, \"score\": score} when both fields are valid.\n # Return None for a missing name, invalid integer text, or a score outside 0..100.\n pass\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\n# Print Rejected for None; otherwise print Name:score.\n","solutionCode":"def clean_record(name_text, score_text):\n name = name_text.strip().title()\n cleaned_score = score_text.strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(cleaned_score)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\nif record is None:\n print(\"Rejected\")\nelse:\n print(record[\"name\"] + \":\" + str(record[\"score\"]))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Split each row into name and score."},"2":{"message":"Strip spaces from each part."},"3":{"message":"Title-case each name."}},"starterFiles":{"main_py":{"content":"def clean_record(name_text, score_text):\n # Return {\"name\": cleaned_name, \"score\": score} when both fields are valid.\n # Return None for a missing name, invalid integer text, or a score outside 0..100.\n pass\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\n# Print Rejected for None; otherwise print Name:score.\n"}},"solutionFiles":{"main_py":{"content":"def clean_record(name_text, score_text):\n name = name_text.strip().title()\n cleaned_score = score_text.strip()\n\n if name == \"\":\n return None\n\n try:\n score = int(cleaned_score)\n except ValueError:\n return None\n\n if score < 0 or score > 100:\n return None\n\n return {\"name\": name, \"score\": score}\n\nname_text = input()\nscore_text = input()\nrecord = clean_record(name_text, score_text)\n\nif record is None:\n print(\"Rejected\")\nelse:\n print(record[\"name\"] + \":\" + str(record[\"score\"]))\n"}}},"sc-clean-before-check":{"title":"Clean before checking","prompt":"A required name arrives as `\" \"`. What should the program do before deciding whether the name is missing?","hint":"Whitespace can hide that nothing meaningful was entered.","help":{"concept":"Clean text first, then validate the cleaned value. `strip()` turns a spaces-only string into the empty string.","hint_1":"Checking the raw string would treat several spaces as non-empty text.","hint_2":"Choose the step that removes surrounding whitespace before the missing-value check."},"options":{"a":"Call `.strip()` and then check the cleaned value","b":"Convert the name with `int()`","c":"Append another space","d":"Write the value to a file first"}},"sc-empty-string":{"title":"Detect a missing cleaned value","prompt":"After `cleaned_name = raw_name.strip()`, which comparison directly checks whether the cleaned name is missing?","hint":"A spaces-only string becomes an empty string after `strip()`.","help":{"concept":"The empty string is written as `\"\"`. It is not the number `0`, `None`, or `False`.","hint_1":"Think about the exact value returned by `\" \".strip()`.","hint_2":"Choose the comparison against an empty string literal."},"options":{"a":"cleaned_name == \"\"","b":"cleaned_name == 0","c":"cleaned_name == None","d":"cleaned_name == False"}},"sc-invalid-integer":{"title":"Handle invalid numeric text","prompt":"A cleaned score is `\"ten\"`. What should a safe integer-validation step expect from `int(score_text)`?","hint":"This is the same conversion error handled in the previous topic.","help":{"concept":"`int(...)` raises `ValueError` when cleaned text still cannot represent a whole number.","hint_1":"Cleaning whitespace does not make the word `ten` numeric.","hint_2":"Choose the specific conversion exception introduced in Try/Except Basics."},"options":{"a":"It raises `ValueError`","b":"It returns 0","c":"It returns `None` automatically","d":"It changes the text to `\"10\"`"}},"sc-score-range":{"title":"Validate the allowed range","prompt":"A score successfully converts to the integer `105`. If valid scores must be from 0 through 100, how should the program classify it?","hint":"Successful conversion does not guarantee the number satisfies the rule.","help":{"concept":"Validation can have multiple stages: first confirm conversion works, then check the allowed numeric range.","hint_1":"105 is an integer, so conversion is not the problem.","hint_2":"Compare 105 with the maximum allowed score of 100."},"options":{"a":"Invalid because it is outside 0 through 100","b":"Valid because every integer is accepted","c":"Missing because it is greater than zero","d":"A `FileNotFoundError`"}}},"tryIt":{"try_validating_and_cleaning_input_checkpoint":{"title":"Try it yourself","prompt":"Read a name. Strip spaces and title-case it. If the cleaned name is empty, print `Missing`; otherwise print the cleaned name."},"try_validating_and_cleaning_input_sketch0":{"title":"Try it yourself","prompt":"Read a name. Store a cleaned version of `raw_name` with surrounding whitespace removed and title case applied in `cleaned_name`. If an explicit comparison between `cleaned_name` and the empty string, print `Missing`; otherwise print the cleaned name."},"try_validating_and_cleaning_input_sketch1":{"title":"Try it yourself","prompt":"Safely validate integer text and its allowed range."},"try_validating_and_cleaning_input_sketch2":{"title":"Try it yourself","prompt":"Complete `clean_record(name_text, score_text)`. Clean the name with whitespace trimming followed by title-case normalization and the score text with `strip()`. Return `None` for an empty cleaned name, invalid integer score text, or a score outside 0 through 100. Otherwise return `{\"name\": name, \"score\": score}`. The caller should print `Rejected` for `None`; otherwise print `Name:score`."},"allowReveal":true}},"working-with-paths":{"label":"Working With Paths","summary":"Use relative paths for same-folder and nested files, build path strings from pieces, and use `pathlib.Path` to join path components before opening a file.","cards":{"sketch0":{"title":"Relative paths describe where a file is"},"sketch1":{"title":"Build a path from folder and file-name pieces"},"sketch2":{"title":"Use pathlib.Path to build and open a path"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-relative-path-folder":{"title":"Choose the relative path","prompt":"A file named `input.txt` is inside a folder named `data`. Which path correctly refers to that file in this lesson?","hint":"Use the folder name first, then the file name.","help":{"concept":"A relative path names folders in order from the current workspace location to the target file.","hint_1":"The file is not in the same folder as the code; it is inside `data`.","hint_2":"Look for the choice that joins the folder and file with a forward slash."},"options":{"a":"input.txt/data","b":"data/input.txt","c":"/data/input.txt","d":"data-input.txt"}},"sc-same-folder-path":{"title":"Path for a nearby file","prompt":"Your code and a file named `notes.txt` are in the same folder. Which path should you use to open that file?","hint":"If the file is in the same folder, you do not need to name another folder.","help":{"concept":"A file in the same folder can be opened with just its file name as a relative path.","hint_1":"No extra folder name is needed here.","hint_2":"Choose the shortest valid path that names only the file itself."},"options":{"a":"data/notes.txt","b":"notes.txt","c":"./data/notes.txt","d":"folder/notes.txt"}},"mc-relative-path-benefits":{"title":"Why use relative paths here?","prompt":"Choose all true statements about using relative paths in this lesson.","hint":"Think about paths that work inside the provided workspace and folders.","help":{"concept":"Relative paths are useful because they describe file locations within the project structure instead of depending on one specific machine setup.","hint_1":"Look for statements about project folders and portability inside the lesson workspace.","hint_2":"Select the choices that describe starting from the current workspace and avoiding machine-specific locations."},"options":{"a":"They can point to files in folders like `data/input.txt`.","b":"They depend on one specific computer's full location.","c":"They help organize files by folder.","d":"They always require a full machine-specific location."}},"mc-open-path-examples":{"title":"Valid relative path examples","prompt":"Choose all paths that are valid relative path examples for this lesson's workspace style.","hint":"Reject any choice that changes the named values, branch order, or output.","help":{"concept":"This question checks whether you can connect the prompt to the Python concept from the lesson.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Try each option in the sentence or code line and keep the one that makes the example work exactly as described."},"options":{"a":"notes.txt","b":"data/input.txt","c":"folder -> input.txt","d":"name of the output panel"}},"dr-read-file-steps":{"title":"Order the file-reading steps","prompt":"Put these steps in the correct order for reading a file with a relative path and showing its contents.","hint":"Open first, then read, then display.","help":{"concept":"Reading a file follows a sequence: open the file, get its contents, then print the result.","hint_1":"You cannot read from the file before opening it.","hint_2":"After reading the text into a variable, the last step is to show it in the output panel."},"tokens":{"t1":"Open `data/input.txt` in read mode","t2":"Store the contents in a variable","t3":"Print the variable"}},"dr-build-nested-path":{"title":"Build the path in order","prompt":"Arrange the tokens to make the relative path to `report.txt` inside the `data` folder.","hint":"Folder name comes before the slash and file name.","help":{"concept":"A nested relative path is built as folder, slash, then file name.","hint_1":"Start with the folder that contains the file.","hint_2":"The slash separates the folder name from the file name."},"tokens":{"t1":"data","t2":"/","t3":"report.txt"}},"fb-folder-part":{"title":"Complete the folder path","prompt":"Fill in the missing folder name.","hint":"Read the complete relative path and include the folder that appears before the filename.","help":{"concept":"A relative path to a file inside a folder includes the folder name before the slash.","hint_1":"The missing part is the folder that contains `input.txt`.","hint_2":"Use the folder name shown throughout the lesson examples."},"template":"[blank1]/input.txt","choices":["data","input","files","read"]},"fb-same-folder-file":{"title":"Complete the same-folder path","prompt":"Fill in the missing file name for a file in the same folder.","hint":"No folder name is needed here.","help":{"concept":"When a file is in the same folder, the relative path is just the file name.","hint_1":"The blank should be the exact file name, not a folder.","hint_2":"Choose the option that is a plain file name ending with `.txt`."},"template":"[blank1]","choices":["data/notes.txt","notes.txt","/notes.txt","folder/notes.txt"]},"ci-read-nested-file":{"title":"Read from a nested relative path","prompt":"Open `data/input.txt`, read the text from that relative path, and print it.\n\nYour output should be exactly:\n`Hello paths!`.","hint":"Read the task \"Read from a nested relative path\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/input.txt\", \"r\") as file:\n # read the text and print it\n pass","solutionCode":"with open(\"data/input.txt\", \"r\") as file:\n text = file.read()\n\nprint(text)","sourceChecks":{"0":{"message":"Open data/input.txt to read the nested file."}}},"ci-copy-between-paths":{"title":"Copy text to another relative path","prompt":"Copy the text from `data/source.txt` into `data/copy.txt`, then print the copied text so we can confirm both files match.\n\nYour output should be exactly:\n`apple`\n`banana`.","hint":"Read the task \"Copy text to another relative path\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"# Read from data/source.txt\n# Write the same text to data/copy.txt\n# Print the copied text","solutionCode":"with open(\"data/source.txt\", \"r\") as source:\n text = source.read()\n\nwith open(\"data/copy.txt\", \"w\") as target:\n target.write(text)\n\nprint(text)","sourceChecks":{"0":{"message":"Read from data/source.txt."},"1":{"message":"Write to data/copy.txt."},"2":{"message":"Use file.write() to create the copy."}}},"ci-count-lines-in-folder":{"title":"Count lines from a file path","prompt":"Open `data/items.txt`, count how many lines it contains, and print the result.\n\nYour output should be exactly:\n`3`.","hint":"Read the task \"Count lines from a file path\" and identify the required result.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"with open(\"data/items.txt\", \"r\") as file:\n # count the lines and print the result\n pass","solutionCode":"with open(\"data/items.txt\", \"r\") as file:\n lines = file.readlines()\n\nprint(len(lines))","sourceChecks":{"0":{"message":"Open data/items.txt to count its lines."}}},"try-working-with-paths-checkpoint":{"title":"Use a relative path","prompt":"Use `Path` to read `data/names.txt`, then print the text without extra characters.","hint":"Use `Path(\"data\") / \"names.txt\"`.","help":{"concept":"Build the relative path first, then use it to read the file.","hint_1":"Create the path with `Path(\"data\") / \"names.txt\"`.","hint_2":"Read that path and print the file text without extra characters."},"starterCode":"from pathlib import Path\n\n# Build a path to data/names.txt and print its contents.\n","starterFiles":{"data_names_txt":{"content":"Ava\nMia\n"}},"solutionFiles":{"main_py":{"content":"from pathlib import Path\n\npath = Path(\"data\") / \"names.txt\"\nprint(path.read_text(), end=\"\")\n"},"data_names_txt":{"content":"Ava\nMia\n"}},"sourceChecks":{"0":{"message":"Use Path(...) to build the path."},"1":{"message":"Build the path with Path('data') / 'names.txt'."}},"solutionCode":"from pathlib import Path\n\npath = Path(\"data\") / \"names.txt\"\nprint(path.read_text(), end=\"\")\n"},"try-working-with-paths-sketch0":{"title":"Build a relative path from input","prompt":"Read a folder name and a file name from input. Build the relative path from those two variables using `folder + \"/\" + filename`, store it in `path`, and print `path`. Build a path string by concatenating `folder`, a forward slash, and `filename` in that order. Store the result in a variable named `path`, then print that variable.","hint":"Use both variables instead of typing a completed path.","help":{"concept":"A path string can be assembled from folder and file-name pieces that are already stored in variables.","hint_1":"Keep `folder` first and `filename` last.","hint_2":"Put the slash string between the two variables."},"starterCode":"folder = input().strip()\nfilename = input().strip()\n\n# Build the relative path from folder and filename, then print it.\n","solutionCode":"folder = input().strip()\nfilename = input().strip()\npath = folder + \"/\" + filename\nprint(path)\n","sourceChecks":{"0":{"message":"Build `path` from the two input variables with `folder + \"/\" + filename`."},"1":{"message":"Print the `path` variable itself."}},"starterFiles":{"main_py":{"content":"folder = input().strip()\nfilename = input().strip()\n\n# Build the relative path from folder and filename, then print it.\n"}},"solutionFiles":{"main_py":{"content":"folder = input().strip()\nfilename = input().strip()\npath = folder + \"/\" + filename\nprint(path)\n"}}},"try-working-with-paths-sketch1":{"title":"Join path pieces with pathlib.Path","prompt":"Read a folder name and file name from input. Use `Path(folder) / filename` to build the path, store it in `path`, and print `path`.","hint":"Use the imported `Path` class and the `/` operator between path components.","help":{"concept":"`Path(folder) / filename` joins path components while keeping the result as a path object.","hint_1":"Do not build the finished path by manually typing a slash string in this exercise.","hint_2":"Print the `path` object after joining the components."},"starterCode":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\n\n# Build a Path from folder and filename, then print it.\n","solutionCode":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\npath = Path(folder) / filename\nprint(path)\n","sourceChecks":{"0":{"message":"Call `Path(...)` because that function call is explicitly required by the prompt."},"1":{"message":"Print the constructed `path` object itself."}},"starterFiles":{"main_py":{"content":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\n\n# Build a Path from folder and filename, then print it.\n"}},"solutionFiles":{"main_py":{"content":"from pathlib import Path\n\nfolder = input().strip()\nfilename = input().strip()\npath = Path(folder) / filename\nprint(path)\n"}}},"try-working-with-paths-sketch2":{"title":"Open a file through a Path object","prompt":"Read a file name from input. Build a `Path` built from the `data` directory and `filename` with pathlib's path-join operator, stored in `path`, open that `path` in read mode, read the text, remove surrounding whitespace, and print it. The workspace provides `data/welcome.txt` and `data/reminder.txt`.","hint":"Build the path first, then pass the `path` variable directly to `open`.","help":{"concept":"A `Path` object can represent the nested relative location and can be passed directly to `open(...)`.","hint_1":"Use `Path(\"data\") / filename` so the input selects the supplied file.","hint_2":"Inside the `with open(path, \"r\")` block, read and strip the text before printing it."},"starterCode":"from pathlib import Path\n\nfilename = input().strip()\n\n# Build a Path inside the data folder.\n# Open that path in read mode and print the stripped text.\n","starterFiles":{"data_message_txt":{"content":"Nested hello\n"},"main_py":{"content":"from pathlib import Path\n\nfilename = input().strip()\n\n# Build a Path inside the data folder.\n# Open that path in read mode and print the stripped text.\n"},"data_welcome_txt":{"content":"Welcome to Python paths!\n"},"data_reminder_txt":{"content":"Remember to save your work.\n"}},"solutionFiles":{"main_py":{"content":"from pathlib import Path\n\nfilename = input().strip()\npath = Path(\"data\") / filename\n\nwith open(path, \"r\") as file:\n text = file.read().strip()\n\nprint(text)\n"},"data_message_txt":{"content":"Nested hello\n"},"data_welcome_txt":{"content":"Welcome to Python paths!\n"},"data_reminder_txt":{"content":"Remember to save your work.\n"}},"sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."}},"solutionCode":"from pathlib import Path\n\nfilename = input().strip()\npath = Path(\"data\") / filename\n\nwith open(path, \"r\") as file:\n text = file.read().strip()\n\nprint(text)\n"},"sc-same-vs-nested":{"title":"Same folder or nested folder","prompt":"Your program is in the workspace root. Which relative path points to `notes.txt` inside the `data` folder?","hint":"Put the containing folder before the file name.","help":{"concept":"A nested relative path names the folder first and then the file, separated by `/`.","hint_1":"`notes.txt` by itself would mean the file is beside `main.py`.","hint_2":"Choose the path that enters `data` before naming `notes.txt`."},"options":{"a":"data/notes.txt","b":"notes.txt/data","c":"/notes.txt","d":"data-notes.txt"}},"sc-path-from-pieces":{"title":"Build a path string from variables","prompt":"If `folder = \"records\"` and `filename = \"scores.txt\"`, which expression builds the relative path `records/scores.txt` from those variables?","hint":"Join folder, slash, and file name in that order.","help":{"concept":"A relative path string can be assembled from existing string variables instead of hard-coding the finished path.","hint_1":"The folder belongs before the slash.","hint_2":"Use both variables so the expression still works if either value changes."},"options":{"a":"folder + \"/\" + filename","b":"filename + \"/\" + folder","c":"\"records/scores.txt\"","d":"folder + filename"}},"sc-pathlib-join":{"title":"Join path parts with Path","prompt":"After `from pathlib import Path`, which expression builds a path from `folder` and `filename`?","hint":"`Path(...)` can be combined with another path part using `/`.","help":{"concept":"`Path(folder) / filename` joins path components without manually inserting a slash string.","hint_1":"Wrap the first path component in `Path(...)`.","hint_2":"Use `/` between the `Path` object and the file-name variable."},"options":{"a":"Path(folder) / filename","b":"Path(folder + filename)","c":"folder.read(filename)","d":"Path / folder / filename()"}},"sc-open-path-object":{"title":"Use a Path object with open","prompt":"If `path` is a `Path` object pointing to a text file, which line opens that path for reading?","hint":"`open(...)` can receive the path object directly.","help":{"concept":"A `Path` object can be passed directly to `open`, just like a relative path string.","hint_1":"Do not convert it to a machine-specific absolute path.","hint_2":"Use the existing `path` variable as the first argument to `open`."},"options":{"a":"with open(path, \"r\") as file:","b":"with path(\"r\") as file:","c":"with open(\"path\", \"r\") as file:","d":"with file.open(\"r\") as path:"}}},"tryIt":{"try_working_with_paths_checkpoint":{"title":"Try it yourself","prompt":"Use `Path` to read `data/names.txt`, then print the text without extra characters."},"try_working_with_paths_sketch0":{"title":"Try it yourself","prompt":"Read a folder name and a file name from input. Build the relative path from those two variables using `folder + \"/\" + filename`, store it in `path`, and print `path`. Build a path string by concatenating `folder`, a forward slash, and `filename` in that order. Store the result in a variable named `path`, then print that variable."},"try_working_with_paths_sketch1":{"title":"Try it yourself","prompt":"Use `Path` to join folder and file-name variables."},"try_working_with_paths_sketch2":{"title":"Try it yourself","prompt":"Read a file name from input. Build a `Path` built from the `data` directory and `filename` with pathlib's path-join operator, stored in `path`, open that `path` in read mode, read the text, remove surrounding whitespace, and print it. The workspace provides `data/welcome.txt` and `data/reminder.txt`."},"allowReveal":true}},"writing-text-files":{"label":"Writing Text Files","summary":"Create or replace text with write mode, preserve existing text with append mode, control line breaks with `\\n`, and reopen the file to verify what was saved.","cards":{"sketch0":{"title":"Write mode creates or replaces a file"},"sketch1":{"title":"Append mode keeps the existing text"},"sketch2":{"title":"Write multiple lines and verify the saved file"},"quiz":{"title":"Check your understanding"}},"quiz":{"sc-write-vs-append":{"title":"Choose the mode that replaces old text","prompt":"Which file mode should you use when you want to overwrite any existing text in a file with new text?","hint":"Use the question wording and the lesson example to narrow the choices.","help":{"concept":"This question checks a specific idea from the lesson, not general test-taking strategy.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Remove options that do not match the concept or evidence named in the question."},"options":{"a":"\"a\"","b":"\"w\"","c":"\"r\"","d":"\"x\""}},"sc-verify-written-text":{"title":"Best way to confirm saved text","prompt":"After writing text to a file in this lesson, what is the best way to make the result visible in the output panel?","hint":"Think about reopening the path and showing the saved contents.","help":{"concept":"File-writing exercises should produce observable output, so a common pattern is to reopen the file and print what was written.","hint_1":"Writing changes the file, but the output panel only shows text you print.","hint_2":"Choose the option that reads the saved text back and displays it."},"options":{"a":"Change the editor theme","b":"Reopen the file and print its contents","c":"Open the notes panel","d":"Rename the variable"}},"mc-append-true-statements":{"title":"Facts about append mode","prompt":"Choose all true statements about opening a file with append mode (`\"a\"`).","hint":"Append mode keeps old text and adds new text after it.","help":{"concept":"Append mode writes at the end of existing contents instead of clearing the file first.","hint_1":"Look for statements that describe keeping existing text.","hint_2":"Reject any option that says append mode erases the file before writing."},"options":{"a":"It keeps the existing contents.","b":"It adds new text at the end of the file.","c":"It always removes everything already in the file.","d":"It can be used to add another line to a log."}},"mc-good-writing-patterns":{"title":"Useful patterns when writing text files","prompt":"Choose all practices that fit this topic's file-writing workflow.","hint":"Think about writing text, then making the result observable.","help":{"concept":"Beginner file-writing programs often use `with open(...)` for safe access, newline characters for line breaks, and printed verification after writing.","hint_1":"Look for patterns involving `with open`, `\\n`, and printing saved text.","hint_2":"Avoid choices unrelated to writing or checking file contents."},"options":{"a":"Use `with open(...)` so the file is handled cleanly.","b":"Use `\\n` when you want the next text on a new line.","c":"Print the saved contents after writing so the result is visible.","d":"Change the notes panel before writing."}},"dr-write-file-steps":{"title":"Order the write-and-check steps","prompt":"Put these steps in the correct order for a simple program that writes text and then verifies it.","hint":"Write first, then reopen and display the saved text.","help":{"concept":"A common workflow is open in write mode, write text, reopen in read mode, then print the contents.","hint_1":"The file must be opened for writing before `write()` can happen.","hint_2":"Printing comes after reading the saved contents back."},"tokens":{"t1":"Open the path with mode \"w\"","t2":"Write the text","t3":"Open the same path for reading","t4":"Print the file contents"}},"dr-append-log-sequence":{"title":"Order the append workflow","prompt":"Arrange these actions to show how a program can create a starting log entry, append another entry, and then display the full log.","hint":"The first write creates the starting text before append adds more.","help":{"concept":"To demonstrate append mode clearly, first create initial contents, then append new text, then read the whole file back.","hint_1":"You need some starting text before the append step makes sense.","hint_2":"Reading and printing the full log should happen after both writes are finished."},"tokens":{"t1":"Open the log with mode \"w\" and write the first line","t2":"Open the log with mode \"a\" and add another line","t3":"Open the log for reading","t4":"Print the full log text"}},"fb-write-mode-code":{"title":"Fill the write mode","prompt":"Complete the mode so this code opens the file for overwriting text.","hint":"Focus on the missing concept rather than the exact missing term.","help":{"concept":"The blank should be completed with the term that fits the job being described.","hint_1":"Focus on what the blank or answer stands for: a value, a method, a key, an index, or a variable name.","hint_2":"Choose the term that best completes the meaning of the statement."},"template":"with open(\"report.txt\", [blank1]) as file:","choices":["\"r\"","\"a\"","\"w\"","\"x\""]},"fb-newline-choice":{"title":"Fill the line break","prompt":"Choose the text that starts a new line after `First line`.","hint":"Read the sentence around the blank and decide what role the missing word plays.","help":{"concept":"The blank needs the exact Python word or symbol that makes the line do what the prompt describes.","hint_1":"Look at the code around the blank to decide whether you need a keyword, a value, a method, or a key.","hint_2":"Choose the option that makes the full line valid Python and gives the result the prompt asks for."},"template":"file.write(\"First line[blank1]Second line\")","choices":["\\t","\\n","\\r"]},"ci-write-greeting-file":{"title":"Write a personalized greeting file","prompt":"Write a greeting into `greeting.txt` using the input name in title case, then open `greeting.txt` and print its contents.\n\nFor example, if the input is `zoe`, your program should print:\n`Hello, Zoe!`.","hint":"Use `input()` for the name, then write the formatted greeting into the file.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"name = input()\n\n# Write Hello, NAME! to greeting.txt.\n# Then open greeting.txt and print its contents.\n","solutionCode":"name = input().strip().title()\n\nwith open(\"greeting.txt\", \"w\") as file:\n file.write(f\"Hello, {name}!\")\n\nwith open(\"greeting.txt\") as file:\n print(file.read())\n","sourceChecks":{"0":{"message":"Write to greeting.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write greeting.txt."}}},"ci-overwrite-shopping-list":{"title":"Overwrite a shopping list from input","prompt":"A shopping list needs to be rewritten from fresh input. Write both items to `shopping.txt`, one per line and in title case, then print the file contents.\n\nFor example, if the inputs are `bread` and `apples`, your program should print:\n`Bread`\n`Apples`.","hint":"Opening a file with `\"w\"` replaces the old contents.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"first_item = input()\nsecond_item = input()\n\n# Write both items to shopping.txt, one per line.\n# Then print the file contents.\n","solutionCode":"first_item = input().strip().title()\nsecond_item = input().strip().title()\n\nwith open(\"shopping.txt\", \"w\") as file:\n file.write(first_item + \"\\n\")\n file.write(second_item + \"\\n\")\n\nwith open(\"shopping.txt\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Write to shopping.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write shopping.txt."}}},"ci-append-log-entry":{"title":"Append a log entry","prompt":"The log already starts with one line. Append the new input entry to `log.txt` on a new line, then print the full file.\n\nFor example, if the input is `Checked sensors`, your program should print:\n`Start shift`\n`Checked sensors`.","hint":"Opening a file with `\"a\"` keeps the old contents and adds new text at the end.","help":{"concept":"This project step is incremental: the starter code is a stable project state plus one new task to complete.","hint_1":"Do not delete working code from the previous step; add the new behavior requested in this step.","hint_2":"Run the program and compare the output to the expected example before checking your answer."},"starterCode":"entry = input()\n\n# Append the entry to log.txt on a new line, then print the full file.\n","solutionCode":"entry = input().strip()\n\nwith open(\"log.txt\", \"a\") as file:\n file.write(\"\\n\" + entry)\n\nwith open(\"log.txt\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Append to log.txt instead of only printing the answer."},"1":{"message":"Open log.txt in append mode."}}},"try-writing-text-files-checkpoint":{"title":"Write and read a text file","prompt":"Write `Hello from a file!` to `note.txt`, then read the file and print the saved text.","hint":"Open the file in write mode first, then reopen it for reading.","help":{"concept":"Write the file first, then reopen it so you can show exactly what was saved.","hint_1":"Open `note.txt` in write mode and save `Hello from a file!`.","hint_2":"Reopen `note.txt` in read mode and print the text you just wrote."},"starterCode":"# Write Hello from a file! to note.txt.\n# Then read note.txt and print it.\n","solutionCode":"with open(\"note.txt\", \"w\") as file:\n file.write(\"Hello from a file!\")\n\nwith open(\"note.txt\") as file:\n print(file.read())\n","sourceChecks":{"0":{"message":"Write to note.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write the file."}}},"try-writing-text-files-sketch0":{"title":"Replace an old status with fresh input","prompt":"`status.txt` already contains old text. Read one status from input, clean it with whitespace trimming followed by title-case normalization, open `status.txt` with mode `\"w\"`, and write the cleaned status followed by a newline. Then reopen `status.txt` in read mode and print exactly what is saved.","hint":"Write mode should replace the supplied old contents, not add after them.","help":{"concept":"Use mode `\"w\"` when the new text should replace whatever the file contained before.","hint_1":"Store `input().strip().title()` in `status`.","hint_2":"Write `status + \"\\n\"`, then reopen the same file with `\"r\"` and print its contents."},"starterCode":"status = input()\n\n# Clean status, replace status.txt with the new line,\n# then reopen the file and print what was saved.\n","solutionCode":"status = input().strip().title()\n\nwith open(\"status.txt\", \"w\") as file:\n file.write(status + \"\\n\")\n\nwith open(\"status.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Write to note.txt instead of only printing Done."},"1":{"message":"Use file.write() to write note.txt."}},"starterFiles":{"main_py":{"content":"status = input()\n\n# Clean status, replace status.txt with the new line,\n# then reopen the file and print what was saved.\n"},"status_txt":{"content":"Old status\n"}},"solutionFiles":{"main_py":{"content":"status = input().strip().title()\n\nwith open(\"status.txt\", \"w\") as file:\n file.write(status + \"\\n\")\n\nwith open(\"status.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"status_txt":{"content":"Old status\n"}}},"try-writing-text-files-sketch1":{"title":"Append a new log entry","prompt":"`log.txt` already contains `Start shift` on its first line. Read one new entry from input, remove surrounding whitespace, append that entry plus a newline with mode `\"a\"`, then reopen the file and print the complete log. Open `log.txt` in append mode inside a `with` block, write the cleaned entry followed by a newline, then reopen the file for reading and use `read()` to print the complete saved contents. After appending the new line, reopen `log.txt` for reading and use `file.read()` to print the complete saved file.","hint":"Append mode should preserve `Start shift` and add the new entry after it.","help":{"concept":"Use mode `\"a\"` when existing text must remain and the new text belongs at the end.","hint_1":"Store `input().strip()` in `entry`.","hint_2":"Write `entry + \"\\n\"` in append mode, then read the whole log back."},"starterCode":"entry = input()\n\n# Clean entry, append it to log.txt on a new line,\n# then reopen the file and print the complete log.\n","solutionCode":"entry = input().strip()\n\nwith open(\"log.txt\", \"a\") as file:\n file.write(entry + \"\\n\")\n\nwith open(\"log.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Open `log.txt` in append mode `\"a\"` so the existing line is preserved."},"1":{"message":"Write the new entry to the file with `write()`."},"2":{"message":"Read the saved file back with `read()` before displaying the complete log."}},"starterFiles":{"main_py":{"content":"entry = input()\n\n# Clean entry, append it to log.txt on a new line,\n# then reopen the file and print the complete log.\n"},"log_txt":{"content":"Start shift\n"}},"solutionFiles":{"main_py":{"content":"entry = input().strip()\n\nwith open(\"log.txt\", \"a\") as file:\n file.write(entry + \"\\n\")\n\nwith open(\"log.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"log_txt":{"content":"Start shift\n"}}},"try-writing-text-files-sketch2":{"title":"Create a two-line report","prompt":"Read a name and a score from input. Clean the name with whitespace trimming followed by title-case normalization and the score with `.strip()`. Create `report.txt` with mode `\"w\"`. Write exactly two lines: `Name: <name>` and `Score: <score>`, each ending with `\\n`. Reopen the file and print exactly what was saved.","hint":"Use two `file.write(...)` calls so each report line ends with `\\n`.","help":{"concept":"Several calls to `file.write()` can build a multi-line text file deliberately.","hint_1":"Write the name line first and the score line second.","hint_2":"After the write block ends, reopen `report.txt` in read mode and print its contents."},"starterCode":"name = input()\nscore = input()\n\n# Clean the inputs, create report.txt with two labeled lines,\n# then reopen the file and print exactly what was saved.\n","solutionCode":"name = input().strip().title()\nscore = input().strip()\n\nwith open(\"report.txt\", \"w\") as file:\n file.write(\"Name: \" + name + \"\\n\")\n file.write(\"Score: \" + score + \"\\n\")\n\nwith open(\"report.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Write to report.txt instead of only printing the answer."},"1":{"message":"Use file.write() to write report.txt."}},"starterFiles":{"main_py":{"content":"name = input()\nscore = input()\n\n# Clean the inputs, create report.txt with two labeled lines,\n# then reopen the file and print exactly what was saved.\n"}},"solutionFiles":{"main_py":{"content":"name = input().strip().title()\nscore = input().strip()\n\nwith open(\"report.txt\", \"w\") as file:\n file.write(\"Name: \" + name + \"\\n\")\n file.write(\"Score: \" + score + \"\\n\")\n\nwith open(\"report.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"}}},"sc-write-mode-effect":{"title":"What write mode does","prompt":"A file already contains `Old text`. What happens when you open that same path with mode `\"w\"` and write `New text`?","hint":"Write mode does not keep the old contents.","help":{"concept":"Opening a text file with mode `\"w\"` creates the file if needed or replaces its existing contents before new text is written.","hint_1":"The old text is not appended after the new text.","hint_2":"Choose the result containing only the newly written text."},"options":{"a":"The file contains only `New text`","b":"The file contains `Old textNew text`","c":"The file stays unchanged","d":"Python automatically switches to read mode"}},"sc-append-mode-effect":{"title":"What append mode does","prompt":"Which statement correctly describes opening an existing text file with mode `\"a\"`?","hint":"Append mode preserves what is already there.","help":{"concept":"Append mode keeps the existing contents and writes new text at the end of the file.","hint_1":"It does not clear the file first.","hint_2":"Choose the option that preserves old text and adds new text after it."},"options":{"a":"It keeps the existing text and writes new text at the end","b":"It always erases the file before writing","c":"It can only read the existing text","d":"It automatically sorts every line"}},"sc-newline-writing":{"title":"Write the next value on a new line","prompt":"Which string contains two lines when written to a text file?","hint":"The newline escape sequence is `\\n`.","help":{"concept":"`\\n` represents a line break inside a Python string.","hint_1":"The line break belongs between the two pieces of text.","hint_2":"Choose the string containing `\\n` between `First` and `Second`."},"options":{"a":"\"First\\nSecond\"","b":"\"First Second\"","c":"\"First\\tSecond\"","d":"\"First/Second\""}},"sc-verify-saved-file":{"title":"Verify what was saved","prompt":"After a program finishes writing a file, which pattern lets you show the actual saved contents in the output panel?","hint":"Reopen the same path for reading and print what `.read()` returns.","help":{"concept":"Writing changes the file, while reopening it in read mode and printing `.read()` makes the saved contents visible.","hint_1":"Use the same path that was written.","hint_2":"Choose the option that reads the file back instead of printing a separate hard-coded message."},"options":{"a":"Reopen the file in read mode and print `file.read()`","b":"Print the file name as a string","c":"Open a different file and ignore the saved one","d":"Change the variable name used for the writer"}}},"tryIt":{"try_writing_text_files_checkpoint":{"title":"Try it yourself","prompt":"Write `Hello from a file!` to `note.txt`, then read the file and print the saved text."},"try_writing_text_files_sketch0":{"title":"Try it yourself","prompt":"`status.txt` already contains old text. Read one status from input, clean it with whitespace trimming followed by title-case normalization, open `status.txt` with mode `\"w\"`, and write the cleaned status followed by a newline. Then reopen `status.txt` in read mode and print exactly what is saved."},"try_writing_text_files_sketch1":{"title":"Try it yourself","prompt":"`log.txt` already contains `Start shift` on its first line. Read one new entry from input, remove surrounding whitespace, append that entry plus a newline with mode `\"a\"`, then reopen the file and print the complete log. Open `log.txt` in append mode inside a `with` block, write the cleaned entry followed by a newline, then reopen the file for reading and use `read()` to print the complete saved contents. After appending the new line, reopen `log.txt` for reading and use `file.read()` to print the complete saved file."},"try_writing_text_files_sketch2":{"title":"Try it yourself","prompt":"Read a name and a score from input. Clean the name with whitespace trimming followed by title-case normalization and the score with `.strip()`. Create `report.txt` with mode `\"w\"`. Write exactly two lines: `Name: <name>` and `Score: <score>`, each ending with `\\n`. Reopen the file and print exactly what was saved."},"allowReveal":true}}},"python-8-real-world-project":{"community-event-registration-cleaner":{"label":"Final Capstone: Community Event Registration Cleaner","summary":"Build one cumulative registration-cleaning tool that reads CSV rows, validates messy data, moves reusable logic into sibling helper modules, summarizes accepted registrations, writes two report files, and verifies the saved artifacts.","cards":{"sketch0":{"title":"A new domain, the same engineering habits"},"project":{"title":"Community Event Registration Cleaner"}},"projectSteps":{"cp_1":{"title":"Clean and validate one registration"},"cp_2":{"title":"Collect only valid registrations"},"cp_3":{"title":"Move cleaning into a helper module"},"cp_4":{"title":"Add summary helper functions"},"cp_5":{"title":"Write the final report files"},"cp_6":{"title":"Verify the saved artifacts"}},"quiz":{"try-community-event-registration-cleaner-sketch0":{"title":"Inspect the registration export","prompt":"Open `data/registrations.csv` in read mode with `csv.DictReader`. Loop through every data row and print `name|event|seats|email` using the named columns exactly as they appear in the file. Do not clean or reject anything yet.","hint":"Inspect the real CSV shape before you design the cleaner.","help":{"concept":"The preview establishes that the capstone uses a header-based CSV file and named columns, not hand-written row splitting.","hint_1":"Create `reader = csv.DictReader(file)` inside the open-file block.","hint_2":"Loop through `reader` and use all four named columns from each row."},"starterCode":"import csv\n\n# Open data/registrations.csv in read mode.\n# Use csv.DictReader and print every row as name|event|seats|email.\n","starterFiles":{"data_registration_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \n"},"main_py":{"content":"import csv\n\n# Open data/registrations.csv in read mode.\n# Use csv.DictReader and print every row as name|event|seats|email.\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n"},"data_registration_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use a `for` loop as the prompt requests."},"2":{"message":"Normalize the attendee name."},"3":{"message":"Normalize the email address."}}},"cp-1-read-registration-file":{"title":"Clean and validate one registration","prompt":"Start from the CSV preview. Add `clean_row(row)`. Clean `name` with whitespace trimming followed by title-case normalization, strip `event`, strip and lowercase `email`, and strip the seat text before conversion. Return `None` when the cleaned name, event, or email is empty, when seats cannot convert with `int()`, or when seats is less than 1. Otherwise return a dictionary with keys `name`, `event`, `seats`, and `email`. Print `clean_row(row)` for every CSV row so you can see which rows are accepted. Inside `clean_row(row)`, clean the required fields with the specified string methods: trim whitespace from each text field, title-case the cleaned name, lowercase the cleaned email, and convert the cleaned seat text to an integer. Catch `ValueError` when the seat conversion fails.","hint":"Apply the cleaning and validation rules inside one reusable function.","help":{"concept":"`clean_row(row)` should return one dependable shape for valid data and `None` for every rejected registration.","hint_1":"Check missing cleaned text before converting the seat count.","hint_2":"Catch exactly `ValueError`, then reject seat counts below 1."},"starterCode":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n","starterFiles":{"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(row[\"name\"] + \"|\" + row[\"event\"] + \"|\" + row[\"seats\"] + \"|\" + row[\"email\"])\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n","sourceChecks":{"0":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"1":{"message":"Use the explicitly requested dictionary field `name`."},"2":{"message":"Use the explicitly requested dictionary field `event`."},"3":{"message":"Use the explicitly requested dictionary field `seats`."},"4":{"message":"Use the explicitly requested dictionary field `email`."},"5":{"message":"Use `strip()` because that method is explicitly required by the prompt."},"6":{"message":"Use `title()` because that method is explicitly required by the prompt."},"7":{"message":"Call `int(...)` because that function call is explicitly required by the prompt."}}},"cp-2-clean-one-registration":{"title":"Collect only valid registrations","prompt":"Keep the working `clean_row(row)` function. Replace the row-by-row preview with a list named `records`. For each CSV row, call `clean_row(row)` once, store the result in `record`, and append it only when it is not `None`. Print the final `records` list.","hint":"Let `clean_row` decide validity; this step should only collect accepted results.","help":{"concept":"Separating cleaning from collection keeps the workflow readable and prevents duplicated validation logic.","hint_1":"Create `records = []` before opening the file.","hint_2":"Use `if record is not None:` before `records.append(record)`."},"starterCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n","starterFiles":{"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n print(clean_row(row))\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","sourceChecks":{"0":{"message":"Call `clean_row(...)` because that function call is explicitly required by the prompt."}}},"cp-3-skip-bad-registration-rows":{"title":"Move cleaning into a helper module","prompt":"Keep the same accepted `records` behavior, but move the complete `clean_row(row)` function out of `main.py` into a new sibling file named `cleaning.py`. Import it with a from-import that brings `clean_row` in from the `cleaning` module. Do not create a package or `__init__.py`; Module 6 used direct sibling helper modules.","hint":"Move one responsibility without changing the program's behavior.","help":{"concept":"A sibling helper module lets `main.py` orchestrate the workflow while `cleaning.py` owns row cleaning and validation.","hint_1":"Create `cleaning.py` beside `main.py` and place the complete working function there.","hint_2":"Remove the local function definition from `main.py` and import `clean_row` directly."},"starterCode":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","starterFiles":{"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\n\ndef clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","sourceChecks":{"0":{"message":"Use the requested import for `clean_row` from `cleaning`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Preserve the deterministic output contract."}}},"cp-4-move-cleaning-to-module":{"title":"Add summary helper functions","prompt":"Create a new sibling file named `summary.py` with `total_seats(records)` and `event_counts(records)`. `total_seats` should use a normal loop to add each record's seats. `event_counts` should build a dictionary by incrementing each event name. Import both helpers in `main.py`, then print `Total seats: <total>` followed by each `event: count` in the dictionary's first-seen event order. In `summary.py`, compute the summary values with a `for` loop over `records`. In `main.py`, print each event/count pair with a `for` loop over the dictionary produced by the event-count helper.","hint":"Use normal loops and dictionaries so the summary stays within concepts already taught.","help":{"concept":"Summary helpers should accept `records` and return values without reading or writing files themselves.","hint_1":"Build the seat total with an accumulator loop.","hint_2":"For counts, use `if event in counts:` to increment an existing key or create it with 1."},"starterCode":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n","starterFiles":{"tools_cleaning_py":{"content":"def clean_row(line):\n # Move the working cleaning logic here.\n pass\n"},"tools___init___py":{"content":""},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\nprint(records)\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools___init___py":{"content":""},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","sourceChecks":{"0":{"message":"Use the requested import involving `summary`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"3":{"message":"Use a `for` loop as the prompt requests."},"4":{"message":"Use a `for` loop as the prompt requests."}}},"cp-5-add-summary-functions":{"title":"Write the final report files","prompt":"Create a sibling file named `reports.py` with `write_clean_registrations(records)` and `write_summary(total, counts)`. Write `output/clean_registrations.csv` in `\"w\"` mode with the header `name,event,seats,email` and one accepted record per line. Write `output/summary.txt` in `\"w\"` mode with `Total seats: <total>` followed by each `event: count`. Import and call both helpers from `main.py`, then print the concise console summary. The old output files already exist and must be replaced.","hint":"The output files already exist, so ordinary write mode is enough; no directory-creation API is needed.","help":{"concept":"Keep file writing in `reports.py` while `main.py` coordinates cleaning, summarizing, and reporting.","hint_1":"Use fixed output paths inside the report functions rather than default parameters.","hint_2":"Write event counts by looping directly through the counts dictionary; do not sort them."},"starterCode":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","starterFiles":{"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n pass\n\n\ndef event_counts(records):\n pass\n"},"tools___init___py":{"content":""},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n return sum(record[\"seats\"] for record in records)\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n counts[event] = counts.get(event, 0) + 1\n return counts\n"},"tools___init___py":{"content":""},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"reports_py":{"content":"def write_clean_registrations(records):\n with open(\"output/clean_registrations.csv\", \"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(\n record[\"name\"] + \",\" +\n record[\"event\"] + \",\" +\n str(record[\"seats\"]) + \",\" +\n record[\"email\"] + \"\\n\"\n )\n\n\ndef write_summary(total, counts):\n with open(\"output/summary.txt\", \"w\") as file:\n file.write(\"Total seats: \" + str(total) + \"\\n\")\n for event in counts:\n file.write(event + \": \" + str(counts[event]) + \"\\n\")\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","sourceChecks":{"0":{"message":"Use the requested import involving `reports`."},"1":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"2":{"message":"Follow the exact code structure that is explicitly shown in the prompt."},"3":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"4":{"message":"Use the literal expression or path that the prompt explicitly asks for."}}},"cp-6-write-final-reports":{"title":"Verify the saved artifacts","prompt":"Keep the complete cleaner, helper modules, summaries, and report writers. After writing both output files, print `Cleaned <count> registrations`, then reopen `output/clean_registrations.csv` and `output/summary.txt` in read mode and print their exact saved contents. The grader checks the files themselves as well as the console output.","hint":"Verify the durable artifacts rather than trusting only the in-memory values.","help":{"concept":"The final capstone should prove that the CSV and summary files were actually overwritten with the cleaned data.","hint_1":"Reopen each output path after the report functions finish.","hint_2":"Use `print(file.read(), end=\"\")` so the saved contents appear exactly as written."},"starterCode":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n","starterFiles":{"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n return sum(record[\"seats\"] for record in records)\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n counts[event] = counts.get(event, 0) + 1\n return counts\n"},"tools_reports_py":{"content":"from pathlib import Path\n\n\ndef write_clean_registrations(records, path=\"output/clean_registrations.csv\"):\n pass\n\n\ndef write_summary(total, counts, path=\"output/summary.txt\"):\n pass\n"},"tools___init___py":{"content":""},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\nprint(\"Total seats: \" + str(total))\nfor event in counts:\n print(event + \": \" + str(counts[event]))\n"},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"reports_py":{"content":"def write_clean_registrations(records):\n with open(\"output/clean_registrations.csv\", \"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(\n record[\"name\"] + \",\" +\n record[\"event\"] + \",\" +\n str(record[\"seats\"]) + \",\" +\n record[\"email\"] + \"\\n\"\n )\n\n\ndef write_summary(total, counts):\n with open(\"output/summary.txt\", \"w\") as file:\n file.write(\"Total seats: \" + str(total) + \"\\n\")\n for event in counts:\n file.write(event + \": \" + str(counts[event]) + \"\\n\")\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionFiles":{"main_py":{"content":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\n\nwith open(\"output/clean_registrations.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n\nwith open(\"output/summary.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n"},"data_registrations_csv":{"content":"name,event,seats,email\n ava smith ,Python Night,2, AVA@EXAMPLE.COM \nMia Chen,Data Clinic,not-a-number,mia@example.com\n ,Python Night,1,blank@example.com\nZoe Ray,Python Night,1,zoe@example.com\nLeo West,Web Workshop,3, leo@example.com \nNia Moss,Data Clinic,0,nia@example.com\nOmar Hill,Data Clinic,2, \n"},"tools_cleaning_py":{"content":"def clean_row(line):\n name, event, seats, email = line.strip().split(\",\")\n return {\"name\": name.strip().title(), \"event\": event.strip(), \"seats\": int(seats), \"email\": email.strip().lower()}\n"},"tools_summary_py":{"content":"def total_seats(records):\n return sum(record[\"seats\"] for record in records)\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n counts[event] = counts.get(event, 0) + 1\n return counts\n"},"tools_reports_py":{"content":"from pathlib import Path\n\n\ndef write_clean_registrations(records, path=\"output/clean_registrations.csv\"):\n output_path = Path(path)\n output_path.parent.mkdir(parents=True, exist_ok=True)\n with output_path.open(\"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(f\"{record['name']},{record['event']},{record['seats']},{record['email']}\\n\")\n\n\ndef write_summary(total, counts, path=\"output/summary.txt\"):\n output_path = Path(path)\n output_path.parent.mkdir(parents=True, exist_ok=True)\n with output_path.open(\"w\") as file:\n file.write(f\"Total seats: {total}\\n\")\n for event, count in sorted(counts.items()):\n file.write(f\"{event}: {count}\\n\")\n"},"tools___init___py":{"content":""},"cleaning_py":{"content":"def clean_row(row):\n name = row[\"name\"].strip().title()\n event = row[\"event\"].strip()\n seats_text = row[\"seats\"].strip()\n email = row[\"email\"].strip().lower()\n\n if name == \"\" or event == \"\" or email == \"\":\n return None\n\n try:\n seats = int(seats_text)\n except ValueError:\n return None\n\n if seats < 1:\n return None\n\n return {\"name\": name, \"event\": event, \"seats\": seats, \"email\": email}\n"},"summary_py":{"content":"def total_seats(records):\n total = 0\n for record in records:\n total += record[\"seats\"]\n return total\n\n\ndef event_counts(records):\n counts = {}\n for record in records:\n event = record[\"event\"]\n if event in counts:\n counts[event] += 1\n else:\n counts[event] = 1\n return counts\n"},"reports_py":{"content":"def write_clean_registrations(records):\n with open(\"output/clean_registrations.csv\", \"w\") as file:\n file.write(\"name,event,seats,email\\n\")\n for record in records:\n file.write(\n record[\"name\"] + \",\" +\n record[\"event\"] + \",\" +\n str(record[\"seats\"]) + \",\" +\n record[\"email\"] + \"\\n\"\n )\n\n\ndef write_summary(total, counts):\n with open(\"output/summary.txt\", \"w\") as file:\n file.write(\"Total seats: \" + str(total) + \"\\n\")\n for event in counts:\n file.write(event + \": \" + str(counts[event]) + \"\\n\")\n"},"output_clean_registrations_csv":{"content":"old registrations export\n"},"output_summary_txt":{"content":"old summary\n"}},"solutionCode":"import csv\nfrom cleaning import clean_row\nfrom reports import write_clean_registrations, write_summary\nfrom summary import event_counts, total_seats\n\nrecords = []\n\nwith open(\"data/registrations.csv\", \"r\") as file:\n reader = csv.DictReader(file)\n for row in reader:\n record = clean_row(row)\n if record is not None:\n records.append(record)\n\ntotal = total_seats(records)\ncounts = event_counts(records)\n\nwrite_clean_registrations(records)\nwrite_summary(total, counts)\n\nprint(\"Cleaned \" + str(len(records)) + \" registrations\")\n\nwith open(\"output/clean_registrations.csv\", \"r\") as file:\n print(file.read(), end=\"\")\n\nwith open(\"output/summary.txt\", \"r\") as file:\n print(file.read(), end=\"\")\n","sourceChecks":{"0":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"1":{"message":"Use the literal expression or path that the prompt explicitly asks for."},"2":{"message":"Preserve the deterministic output contract."},"3":{"message":"Create the requested output artifact."}}}},"tryIt":{"try_community_event_registration_cleaner_sketch0":{"title":"Try it yourself","prompt":"Inspect the complete registration export with `csv.DictReader` before the capstone starts."},"allowReveal":true}}}},"python-v2":{"python-v2-0":{"module-0-welcome-board-project":{"label":"Module Project: Build a Welcome Board","summary":"Build one Python welcome board in stages. Preserve working code while adding a useful comment, literals, an arithmetic expression, and a final welcome message.","cards":{"sketch0":{"title":"Build one program, one improvement at a time"},"project":{"title":"Welcome Board Builder"}},"projectSteps":{"mp_1":{"title":"Set the event title"},"mp_2":{"title":"Document the board"},"mp_3":{"title":"Add the event time"},"mp_4":{"title":"Add a numeric literal"},"mp_5":{"title":"Calculate the helper count"},"mp_6":{"title":"Finish the welcome board"}},"quiz":{"mp-1-set-event-title":{"title":"Set the event title","prompt":"Start the welcome board with one line that prints exactly:\n\n`Code Club Open House`","hint":"Use one `print()` call with the title as a string literal.","help":{"concept":"The project begins with one working line. Later stages will keep this line and extend the same program.","hint_1":"The event title is text, so write it as a quoted string.","hint_2":"This stage needs one output line only."},"starterCode":"# Start the board with the event title.\n","solutionCode":"print(\"Code Club Open House\")","sourceChecks":{"0":{"message":"Start with one print call for the exact event title."}}},"mp-2-add-useful-comment":{"title":"Document the board","prompt":"Keep the working title line. Add one useful Python comment on the line above it describing the purpose of the program.\n\nThe program output must still be exactly:\n\n`Code Club Open House`","hint":"A Python comment starts with `#` and should not become output.","help":{"concept":"Comments document code for readers without changing the program's normal output.","hint_1":"Put the comment above the existing `print()` call.","hint_2":"Do not add another printed line in this stage."},"starterCode":"print(\"Code Club Open House\")","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")","sourceChecks":{"0":{"message":"Add one non-empty Python comment immediately above the first `print()` statement."}}},"mp-3-add-event-time":{"title":"Add the event time","prompt":"Keep the comment and title. Add one new output line under the title that prints exactly:\n\n`Doors open at 4 PM`","hint":"Preserve the existing program and add one new `print()` call below the title.","help":{"concept":"A cumulative project grows by preserving correct code and adding one focused improvement.","hint_1":"The comment stays at the top.","hint_2":"The new time line should appear after the event title."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."}}},"mp-4-add-seat-literal":{"title":"Add a numeric literal","prompt":"Keep the board so far. Add these two output lines at the bottom:\n\n`Seats available`\n`24`\n\nPrint `24` as a numeric literal, not as quoted text.","hint":"The label is a string, but the seat count should be the number `24` without quotes.","help":{"concept":"A numeric literal is a number written directly in code. Quoting `24` would turn it into a string instead.","hint_1":"Use one print call for the label and one for the number.","hint_2":"The line for the count should contain `print(24)`, not `print(\"24\")`."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."},"1":{"message":"Print the seat count as the integer literal `24`, not as text."}}},"mp-5-calculate-helper-count":{"title":"Calculate the helper count","prompt":"Keep everything already working. Add these two output lines:\n\n`Helpers ready`\n`6`\n\nDo not type the final `6` directly. Make Python calculate it with the expression `2 * 3`.","hint":"Print the label first, then print the expression `2 * 3` on the next line.","help":{"concept":"An arithmetic expression produces a value. Here the program should calculate the helper count rather than hard-code the result.","hint_1":"Keep `2 * 3` visible in the source code.","hint_2":"The expression should not be inside quotes."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)\nprint(\"Helpers ready\")\nprint(2 * 3)","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."},"1":{"message":"Use the expression `2 * 3` itself to calculate the helper count."}}},"mp-6-add-final-message":{"title":"Finish the welcome board","prompt":"Keep the complete working board from the previous step. Add one final line at the bottom that prints exactly:\n\n`Bring your questions!`\n\nPreserve every earlier line and add only the new final message.","hint":"Start from the working program exactly as it is and add one quoted string in a new `print()` call at the bottom.","help":{"concept":"A cumulative project grows from the previous working solution. The final step should preserve all earlier behavior and add only the new requirement.","hint_1":"Do not rewrite or remove any of the earlier board lines.","hint_2":"The final value is text, so keep it inside matching quotes."},"starterCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)\nprint(\"Helpers ready\")\nprint(2 * 3)","solutionCode":"# Show the welcome board for arriving students\nprint(\"Code Club Open House\")\nprint(\"Doors open at 4 PM\")\nprint(\"Seats available\")\nprint(24)\nprint(\"Helpers ready\")\nprint(2 * 3)\nprint(\"Bring your questions!\")","sourceChecks":{"0":{"message":"Keep the useful Python comment immediately above the first `print()` statement."}}}}},"operators-and-expressions":{"label":"Operators and Expressions","summary":"Use Python arithmetic operators, follow operator precedence, and use parentheses to control grouping.","cards":{"sketch0":{"title":"Arithmetic operators change numeric values"},"sketch1":{"title":"Precedence decides which operation happens first"},"sketch2":{"title":"Parentheses let you choose the grouping"},"quiz":{"title":"Quiz"}},"quiz":{"sc-division-operator":{"title":"Choose the division operator","prompt":"Which Python operator divides one numeric value by another?","hint":"Python uses a keyboard symbol for division.","help":{"concept":"Python uses `+` for addition, `-` for subtraction, `*` for multiplication, and `/` for division.","hint_1":"Do not choose the multiplication symbol.","hint_2":"Choose the slash used in an expression such as `8 / 2`."},"options":{"a":"+","b":"-","c":"*","d":"/"}},"sc-precedence-result":{"title":"Apply operator precedence","prompt":"What value does Python produce for `2 + 3 * 4`?","hint":"Multiplication is evaluated before addition.","help":{"concept":"In an expression without grouping parentheses, multiplication and division are evaluated before addition and subtraction.","hint_1":"Evaluate `3 * 4` before combining the result with `2`.","hint_2":"Do not start by evaluating `2 + 3`."},"options":{"a":"14","b":"20","c":"24","d":"9"}},"mc-operator-matches":{"title":"Match operators to their jobs","prompt":"Which operator descriptions are correct? Choose all correct answers.","hint":"Match each symbol with the arithmetic operation it performs.","help":{"concept":"The four basic arithmetic operators are `+` add, `-` subtract, `*` multiply, and `/` divide.","hint_1":"Check the meaning of each symbol independently.","hint_2":"Two distractors deliberately swap operator meanings."},"options":{"a":"`+` adds numeric values","b":"`*` multiplies numeric values","c":"`/` subtracts numeric values","d":"`-` divides numeric values"}},"dr-precedence-steps":{"title":"Trace an ungrouped expression","prompt":"Arrange the evaluation steps for `18 - 8 / 2`.","hint":"Division happens before subtraction.","help":{"concept":"Python evaluates division before subtraction when there are no parentheses changing the grouping.","hint_1":"Start with `8 / 2`.","hint_2":"Use that result in the remaining subtraction."},"tokens":{"t1":"Evaluate `8 / 2`","t2":"Produce `4.0`","t3":"Evaluate `18 - 4.0`","t4":"Produce `14.0`"}},"dr-grouped-steps":{"title":"Trace a grouped expression","prompt":"Arrange the evaluation steps for `(5 + 2) * 3`.","hint":"The grouped addition is evaluated before the multiplication.","help":{"concept":"Parentheses give the grouped expression priority over the surrounding arithmetic.","hint_1":"Start inside the parentheses.","hint_2":"After the group becomes one value, multiply by `3`."},"tokens":{"t1":"Evaluate `5 + 2`","t2":"Produce `7`","t3":"Evaluate `7 * 3`","t4":"Produce `21`"}},"fb-target-operator":{"title":"Choose the operator for a target","prompt":"Choose the operator that makes this expression produce `18`.","hint":"Ask which operation turns 6 and 3 into 18.","help":{"concept":"Choosing an operator means choosing the arithmetic relationship between the two values.","hint_1":"Addition would produce a much smaller result.","hint_2":"Use the operator for multiplication."},"template":"6 [blank1] 3","choices":["+","-","*","/"]},"ci-use-four-operators":{"title":"Use all four arithmetic operators","prompt":"Write four `print()` statements using the values `12` and `3`:\n1. add them\n2. subtract `3` from `12`\n3. multiply them\n4. divide `12` by `3`\n\nUse the arithmetic expressions themselves inside `print(...)`.","hint":"Use one of `+`, `-`, `*`, and `/` on each line.","help":{"concept":"Each arithmetic operator creates a different numeric expression from the same two values.","hint_1":"Keep the four operations in the order requested.","hint_2":"Do not replace the expressions with their final numeric answers."},"starterCode":"# Add 12 and 3\n# Subtract 3 from 12\n# Multiply 12 and 3\n# Divide 12 by 3\n","solutionCode":"print(12 + 3)\nprint(12 - 3)\nprint(12 * 3)\nprint(12 / 3)","sourceChecks":{"0":{"message":"Use four separate `print()` statements, one for each required expression."},"1":{"message":"Use `12 + 3` itself inside the first `print()` call."},"2":{"message":"Use `12 - 3` itself inside the second `print()` call."},"3":{"message":"Use `12 * 3` itself inside the third `print()` call."},"4":{"message":"Use `12 / 3` itself inside the fourth `print()` call."}}},"ci-follow-precedence":{"title":"Let precedence control the result","prompt":"Write two `print()` statements using these expressions exactly:\n- `2 + 3 * 4`\n- `18 - 8 / 2`\n\nDo not add grouping parentheses. Run the program and observe which operations Python evaluates first.","hint":"Place each complete expression inside its own `print()` call.","help":{"concept":"Without grouping parentheses, multiplication and division have higher precedence than addition and subtraction.","hint_1":"Keep the expressions exactly as written.","hint_2":"The purpose is to observe precedence, not to type the final answers."},"starterCode":"# Print the two ungrouped expressions below.\n","solutionCode":"print(2 + 3 * 4)\nprint(18 - 8 / 2)","sourceChecks":{"0":{"message":"Use two separate `print()` statements, one for each required expression."},"1":{"message":"Use `2 + 3 * 4` itself inside the first `print()` call without grouping parentheses."},"2":{"message":"Use `18 - 8 / 2` itself inside the second `print()` call without grouping parentheses."}}},"ci-change-grouping":{"title":"Change the grouping with parentheses","prompt":"The starter code uses `2 + 3 * 4`. Add parentheses so Python adds `2 + 3` first and then multiplies by `4`. Keep the expression inside `print()`.","hint":"Group the addition that should happen first.","help":{"concept":"Parentheses change grouping by forcing the enclosed expression to be evaluated before the surrounding multiplication.","hint_1":"Do not change the numbers or operators.","hint_2":"Place one pair of parentheses around the addition."},"starterCode":"print(2 + 3 * 4)\n","solutionCode":"print((2 + 3) * 4)","sourceChecks":{"0":{"message":"Use the grouped expression `(2 + 3) * 4` itself inside `print()`."}}},"ci-practice-choose-operator":{"title":"Change one operator to reach the target","prompt":"The starter code prints the value of `8 + 4`. Change only the arithmetic operator so the expression becomes `8` times `4`.","hint":"Keep the two numbers and the `print()` call.","help":{"concept":"Changing one operator changes the relationship between the same two numeric values.","hint_1":"Do not replace the expression with `32`.","hint_2":"Use Python's multiplication operator."},"starterCode":"print(8 + 4)\n","solutionCode":"print(8 * 4)","sourceChecks":{"0":{"message":"Keep `8` and `4`, and change only the arithmetic operator to multiplication: `8 * 4`."}}},"ci-practice-compare-grouping":{"title":"Compare grouped and ungrouped expressions","prompt":"Write two lines. First print `10 - 2 * 3`. Then print `(10 - 2) * 3`. Keep both expressions visible in the code so you can compare how grouping changes evaluation.","hint":"The second expression groups the subtraction.","help":{"concept":"The same numbers and operators can produce different values when parentheses change which operation happens first.","hint_1":"The first line has no extra grouping around `10 - 2`.","hint_2":"The second line groups `10 - 2` before multiplying."},"starterCode":"# Print the ungrouped expression, then the grouped expression.\n","solutionCode":"print(10 - 2 * 3)\nprint((10 - 2) * 3)","sourceChecks":{"0":{"message":"Use two separate `print()` statements so both expressions remain visible for comparison."},"1":{"message":"Use `10 - 2 * 3` itself inside the first `print()` call."},"2":{"message":"Use `(10 - 2) * 3` itself inside the second `print()` call."}}},"ci-practice-division-precedence":{"title":"Preserve precedence while editing","prompt":"Complete the starter so it prints the value of `20 - 12 / 3`. Keep the expression ungrouped so division happens before subtraction.","hint":"Use the expression itself rather than its final v</article></body></html>