Reference library

Functions & basics

Reusable building blocks — parameters, returns, scope, and clear function design.

2 matches
Functions & basics medium

How to Create a Counter Closure in Python

Build a closure in Python that remembers and increments a counter across calls without using global variables.

closures nonlocal state
Python
def create_counter(start=0):
    count = start
    def increment():
        nonlocal count
        count += 1
        return count
    return increment

if __name__ == "__main__":
    counter = create_counter(10)
    print(counter())
    print(counter())
    print(counter())
13 0 Open
Functions & basics medium

How to Parse Function Signatures in Python with inspect

Extract a function's parameter names, kinds, defaults, annotations, and return type using Python's built-in inspect module.

inspect function signature introspection
Python
import inspect

def example_function(a: int, b: str = "default", *args, c: float = 1.5, **kwargs) -> bool:
    """An example function with various parameter types."""
    return True

def parse_signature(func):
    """Parse a function's signature using the inspect module."""
    sig = inspect.signature(func)
    param…
14 0 Open

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Functions & basics — Python code examples

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This page collects functions & basics snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.