Reference library

Functions & basics

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

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Functions & basics easy

Build a Context Manager in Python with contextlib.contextmanager

Create a reusable context manager that safely opens and closes files using the contextlib contextmanager decorator.

context manager contextlib file handling
Python 
from contextlib import contextmanager

@contextmanager
def managed_file(filename, mode='r'):
    """Context manager that opens and closes a file safely."""
    file = open(filename, mode)
    yield file
    file.close()

if __name__ == "__main__":
    # Write a sample file
    with managed_file("sample.txt", "w") as f…
15 0 Open

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