Topic 3. Functions: parameters and arguments, scope, recursion, and type hints

Goal: learn to decompose a console program into functions, use different parameter kinds, document and annotate contracts, build closures, and check recursive algorithms.

Lecture contents

1. Function definitions and arguments — Definition, call, and result · Positional, keyword, and optional arguments
2. Parameter kinds and passing objects — Parameter kinds and unpacking · Passing objects and pure functions
3. Functions as values and scope — Functions as values and scope
4. Recursion and the call stack — Recursion and the call stack · Recursion, iteration, and repeated calculations
5. Type hints and PyCharm — Type hints in Python 3.14 · Working with functions in PyCharm · Common mistakes and checking contracts

Practice and review

• Practice — 3 worked examples with complete code
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links