python 装饰器 demo

import time


def timer(f):
    # *定义装饰器
    def inner(*args, **kwargs):
        start = time.time()
        func = f(*args, **kwargs)
        end = time.time()
        print("装饰器函数", end - start)
        return func

    return inner


@timer
def add(a, b):
    time.sleep(2)
    return a - b


print(add(3, 1))