day14

装饰器

装饰器本质就是闭包

开放封闭原则：

扩展是开放的（增加新功能），对源码是封闭的（修改已经实现的功能）

装饰器：用来装饰的工具

作用：在不改变源代码及调用方式的基础下额外增加新的功能

应用（面试的时候）：登录认证、日志

增加一些功能

校验用户登录的时候

面向对象

语法糖 -- 甜：@+函数名

语法糖必须放在被装饰的函数正上方

# import time

# def times(f):

#     def inner():

#         start_time = time.time()

#         f()

#         print(time.time() - start_time)

#     return inner

# def foo():

#     time.sleep(1)

#     print('我是立业，我快！')

# foo = times(foo)

# foo()

# def wrapper(f):

#     def inner(*args,**kwargs):

#         f(*args,**kwargs)

#     return inner

# def func(*args,**kwargs):

#     print(f"这是{args,kwargs}函数")

# func = wrapper(func)

# func('alex','sir')

版一

# import time

# start_time = time.time()

# def func():

#     time.sleep(1)

#     print('我要飞')

# func()

# print(time.time() - start_time)

版二

# def times(f):

#     start_time = time.time()

#     f()

#     print(time.time() - start_time)

#

# def foo():

#     time.sleep(1)

#     print('小明')

#

# def func():

#     time.sleep(1)

#     print('章超印')

# s = func

# func = times

# func(s)

# s = foo

# foo = times

# foo(s)

版三

# def times(f):

#     def inner():

#         start_time = time.time()

#         f()

#         print(time.time() - start_time)

#     return inner

#

# def foo():

#     time.sleep(1)

#     print('小明')

# foo = times(foo)

# foo()

# def wrapper():

#     def inner():

#         print(1)

#     return inner

# wrapper()()

# def wrapper():

#     def inner(f):

#         print(f)

#     return inner

#

# def func():

#     print('小明')

# func = wrapper()

# func('alex')

版四

# def wrapper(f):

#     def inner(*args,**kwargs):

#         f(*args,**kwargs)

#     return inner

# def func(*args,**kwargs):

#     print(f'{args,kwargs}')

# func = wrapper(func)

# func(1,2,2,3,4,5,5,a=1,b=2)

# import time

# def wrapper(f):

#     def inner(*args,**kwargs):

#         start_time = time.time()

#         f(*args,**kwargs)

#         print((time.time() - start_time))

#     return inner

# def func(*args,**kwargs):

#     print(f'{args,kwargs}')

#     time.sleep(1)

# func = wrapper(func)

# func(1,2,3,4,54,5,a = 1, b =2)

版五

# import time

# def wrapper(f):

#     def inner(*args,**kwargs):

#         start_time = time.time()

#         print(f(*args,**kwargs))

#         return time.time() - start_time

#     return inner

# @wrapper

# def func(*args,**kwargs):

#     time.sleep(1)

#     print(f'{args,kwargs}')

#     return 'alex'

# @wrapper

# def foo(*args,**kwargs):

#     time.sleep(1)

#     print(f'{args,kwargs}')

# print(func(1,2,3,4,54,5,a = 1, b =2))

# print(foo(1523,2,541,5165,12,6,a='alex',b='eeeee'))

标准版

def func(a):  #a是要被装饰的函数名

    def foo(*args,**kwargs):

        "装饰之前的操作"

        ret = a(*args,**kwargs)

        "装饰之后的操作"

        return ret

    return foo

@func

def f1(*args,**kwargs):

    print(f"这是一个{args}")

    return "我可以返回了"

print(f1(1,2,3,34,4,5,a=1))

博客园

# login_dic = {

#     "username": None,

#     "flag": False

# }

# def auth(f):

#     def inner(*args,**kwargs):

#         if login_dic["flag"]:

#             return f()

#         else:

#             return login()

#     return inner

# @auth

# def index():

#     print(f"这是{login_dic['username']}主页")

#     return "主页没有内容"

# def login():

#     print("这是一个登录页面")

#     user = input("username:")

#     pwd = input("password:")

#     if user == "baoyuan" and pwd == "baoyuan123":

#         login_dic["flag"] = True

#         login_dic["username"] = user

#         return "登录成功!"

#     else:

#         return "用户名或密码错误!"

# @auth

# def comment():

#     print(f"这是{login_dic['username']}评论")

#

# while not login_dic["flag"]:

#     print(comment())

巴特西

day14——装饰器

day14

装饰器

开放封闭原则：

装饰器：用来装饰的工具

语法糖 -- 甜：@+函数名

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