functools.wraps preserves __name__

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Accepted Answer

When you replace a function with a wrapper, Python sees the wrapper - not the original. So __name__ becomes 'wrapper' and __doc__ is None because wrapper has no docstring. This breaks debuggers, logging, pytest output, Sphinx docs, and anything that reflects on function metadata. The fix is functools.wraps: decorate wrapper with @functools.wraps(func) and it copies __name__, __doc__, __module__, __qualname__, and __wrapped__ from the original. Always use @functools.wraps in production decorators - it costs nothing and prevents confusing surprises.