What is the purpose of the wraps decorator in Python?

The wraps decorator from the functools module is used to preserve the metadata of the wrapped function (such as name, docstring, annotations, and module) when creating a wrapper function.

Without wraps, the wrapped function will have the metadata of the wrapper function, which can make debugging, introspection, and tool usage (e.g., Sphinx for documentation) more difficult.

from functools import wraps

def my_decorator(func):
    # Preserves the original function’s metadata
    @wraps(func)
    def wrapper(*args, **kwargs):
        print("Before function call")
        result = func(*args, **kwargs)
        print("After function call")
        return result
    return wrapper

@my_decorator
def greeted_function(name):
    """This is the docstring of the greeted function."""
    print(f"Hello, {name}!")

# Without wraps, greeted_function.__name__ would be 'wrapper',
# greeted_function.__doc__ would be None, etc.
print(f"Function name: {greeted_function.__name__}")
print(f"Function docstring: {greeted_function.__doc__}")

greeted_function("World")

Comparison table:

Attribute	Without functools.wraps	With functools.wraps
__name__	Name of the wrapper function	Original function's name
__doc__	Docstring of the wrapper function	Original function's docstring
__module__	Module of the wrapper function	Original function's module
__annotations__	Annotations of the wrapper function	Annotations of the original function
__wrapped__	Not present	Reference to the original function