python计算代码运行时间的装饰器

import time

def cal_time(func):

    def wrapper(*args, **kwargs):

        t1 = time.time()

        result = func(*args, **kwargs)

        t2 = time.time()

        print("%s running time: %s secs." % (func.__name__, t2-t1))

        return result

    return wrapper