import time

import datetime

def performance(f):

    def fn(x):

        starttime=datetime.datetime.now()

        r=f(x)

        endtime=datetime.datetime.now()

        print endtime-starttime

        return r

    return fn

@performance

def factorial(n):

    return reduce(lambda x,y: x*y, range(1, n+1))

print factorial(10)

网上查了只有datetime的用法...凑合用上了