Why functools.wraps Matters

Easy ⏱ 8 min 75% acceptance ★★★★★ 4.9

Write two decorators, bare(func) (plain wrapper, no wraps) and proper(func) (with @wraps(func)), each just delegating. Then names(f) returns f.__name__ after decoration: bare-decorated functions report 'wrapper', proper ones keep their own name — the debugging/tooling reason wraps exists.

Examples

Example 1

Input

names(bare(greet)), names(proper(greet))

Output

('wrapper', 'greet')

Explanation

wraps copied the metadata; the bare one lost it.

Constraints

Both decorators must delegate correctly.
Only the wraps usage differs.

Topics

Decoratorsfunctools.wraps

Companies

MicrosoftJetBrainsGitLab

Hints

Hint 1

@wraps(func) sits on the inner wrapper.

Hint 2

__doc__ and __qualname__ are copied too.

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