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🧩 Functions — learning path
🧩 Improver12 problemsFree · no login needed
What this path teaches
Arguments, defaults, return values, and scope. The recurring lesson: what a function prints and what it returns are different channels, and defaults are evaluated exactly once — at def time.
By the end: You can read any call site and signature pair and predict the binding — or the TypeError.
Your progress
0 of 12 opened
Start the path →The problems, in order
- 1Calling a function before defining it
- 2Calling a function with too few arguments
- 3Positional arguments in the wrong order
- 4Keyword argument typo
- 5Default parameter values
- 6Function returning nothing
- 7Multiple return values
- 8Unpacking the wrong number of values
- 9Swapping variables with tuples
- 10Tuple unpacking with functions
- 11Modifying a variable before it's assigned locally
- 12Mutable default argument trap
How to work a path
Do the problems in order — each one assumes the rule taught by the one before it. Open a problem, try it in the interactive editor, and only then read the explanation. Progress is saved in this browser automatically (signed-in solves also earn XP and streaks). One path per week is a solid pace; finishing in a single sitting is allowed but not required.