about python __doc__ docstring

Question

i want to show docstring of my function, but if i use like this

@cost_time
def func():
    "define ...."
    blabla
print func.__doc__

it will not show the docstring,just because i use some meta programming tricky, how can fix this?

Answer 1

Use functools.wraps().

Answer 2

Your wrapped function returned from the cost_time decorator must have the docstring instead of func. Therefore, use functools.wraps which correctly sets __name__ and __doc__:

from functools import wraps

def cost_time(fn):
    @wraps(fn)
    def wrapper():
        return fn()

    return wrapper