Functions and Scope Flashcards

What is the difference between `return` and `yield` in Python?

Answer: `return` exits the function and returns a value; `yield` pauses execution and produces a value

`return` terminates the function call, while `yield` suspends it and produces a value, resuming from the same point on the next iteration.

Which of the following is a positional-only parameter syntax introduced in Python 3.8?

Answer: def f(x, /, y):

The `/` separator in a parameter list marks all parameters before it as positional-only — they cannot be passed by keyword.

What does `functools.partial` do?

Answer: Creates a new callable with some arguments pre-filled

`functools.partial(func, *args, **kwargs)` returns a new callable with the given arguments pre-applied to `func`.

What is the scope of a variable defined inside a `for` loop in Python?

Answer: Function scope — it remains accessible after the loop

Python has no block scope; loop variables remain in the enclosing function (or module) scope after the loop finishes.

What does a decorator fundamentally do in Python?

Answer: Wraps a function to extend or alter its behavior without modifying its source

A decorator is a callable that takes a function, adds behavior, and returns a new callable — applied using the `@decorator` syntax.

What is the output of: `def outer(): x = 10; def inner(): print(x); inner(); outer()`?

Answer: 10

`inner` closes over `x` from `outer`'s enclosing scope and can read it, printing `10`.

Which statement correctly describes recursive functions in Python?

Answer: Python enforces a default recursion limit (typically 1000) and raises RecursionError if exceeded

Python sets a default recursion limit (usually 1000) accessible via `sys.getrecursionlimit()`; exceeding it raises `RecursionError`.