python clock装饰器 计算函数执行时间，执行结果及传入的参数

import time
import functools

def clock(func):
    @functools.wraps(func)#还原被装饰函数的__name__和__doc__属性
    def clocked(*args,**kwargs):#支持关键字参数
        t0 = time.perf_counter()
        result = func(*args,**kwargs)
        elapsed = time.perf_counter()- t0
        name = func.__name__
        arg_lst = []
        if args:
            arg_lst.append(','.join(repr(arg) for arg in args))
        if kwargs:
            pairs = ['%s = %r' % (k,w) for k,w in sorted(kwargs.items())]
            arg_lst.append(','.join(pairs))
        arg_str = ','.join(arg_lst)
        print('[%0.8fs]%s(%s) -> %r' % (elapsed,name,arg_str,result))
        return result
    return clocked

@clock
def snooze(seconds):
    time.sleep(seconds)

@clock
def factorial(n):
    return 1 if n<2 else n * factorial(n-1)

if __name__ == '__main__':
    print('*'*40,'Calling snooze(.123)')
    snooze(.123)
    print('*'*40,'Calling factorial(6)')
    print('6! =',factorial(6))