函数装饰器

1、装饰器的实现

1.1 无参装饰器，得出一下代码运行时间，在不改变函数调用方式的情况下

import time


def index():
    time.sleep(2)
    print('hello')
    return 1


index()


def wrapper(func):
    start_time = time.time()
    res = func()
    stop_time = time.time()
    print(f'运行了{stop_time - start_time}')
    return res


wrapper(index)


def calc_time(func):
    def wrapper1():
        start_time = time.time()
        res = func()
        stop_time = time.time()
        print(f'运行了{stop_time - start_time}')
        return res

    return wrapper1


index = calc_time(index)
index()

输出结果：

hello
hello
运行了2.0135855674743652
hello
运行了2.0008928775787354

import time


def calc_time(func):
    def wrapper1(*args, **kwargs):
        start_time = time.time()
        res = func(*args, **kwargs)
        stop_time = time.time()
        print(f'运行了{stop_time - start_time}')
        return res

    return wrapper1


@calc_time  # index = calc_time(index)
def index():
    time.sleep(2)
    print('hello')
    return 1


index()

输出结果：

hello
运行了2.014746904373169

 1.2 有参装饰器

def user_other(engine):
    def deco(func):
        def wrapper(*args, **kwargs):
            if engine == 'file:':
                res = func(*args, **kwargs)
                return res

        return wrapper

    return deco


@user_other(engine='file')
def index():
    return True


index()