#coding=utf8

import time

def performance(unit):

    def fn(f):

        def print_time(*args, **kw):

            t1 = time.time()

            r= f(*args,**kw)

            t2 = time.time()

            t = (t2 - t1)*1000 if unit =='ms' else (t2 - t1)    #如果是ms，则*1000，如果不是则直接得到t2-t1

            print 'call %s() in %f %s' % ( f.__name__ , t, unit)

            return r

        return print_time

    return fn

@performance('ms')

def factorial(n):

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

print factorial(10)

def performance(unit):

    def perf_decorator(f):

        def wrapper(*args, **kw):

            t1 = time.time()

            r = f(*args, **kw)

            t2 = time.time()

            t = (t2 - t1)*1000 if unit =='ms' else (t2 - t1)

            print 'call %s() in %f %s'%(f.__name__, t, unit)

            return r

        return wrapper

    return perf_decorator

@performance('ms')  

def factorial(n):

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

print factorial(10)