装饰器进阶

2019 年 7 月 24 日

老师上课主要是两个内容

有参装饰器

login_dic = {

    "username": None,

    "flag": False

}

# 正确的案例

msg = """

QQ

微信

抖音

邮箱

请输入您要选择登陆的app:

"""

chose = input(msg).upper()



def auth(argv):

    def wrapper(func):

        def inner(*args,**kwargs):

            if login_dic["flag"]:

                func(*args,**kwargs)

            else:

                if argv == "QQ":

                    print("欢迎登陆QQ")

                    user = input("username:")

                    pwd = input("password:")

                    if user == "alex" and pwd == "alex123":  # qq

                        login_dic["flag"] = True

                        login_dic["username"] = user

                        func(*args,**kwargs)

                    else:

                        print("用户名或密码错误!")

                elif argv == "微信":

                    print("欢迎登陆微信")

                    user = input("username:")

                    pwd = input("password:")

                    if user == "1351101501" and pwd == "alex":  # 微信

                        login_dic["flag"] = True

                        login_dic["username"] = user

                        func(*args, **kwargs)

                    else:

                        print("用户名或密码错误!")

                elif argv == "抖音":

                    print("来了,老弟!")

                    user = input("username:")

                    pwd = input("password:")

                    if user == "alexdsb" and pwd == "alex":  # 抖音

                        login_dic["flag"] = True

                        login_dic["username"] = user

                        func(*args, **kwargs)

                    else:

                        print("用户名或密码错误!")

                else:

                    print("欢迎登陆dab邮箱")

                    user = input("username:")

                    pwd = input("password:")

                    if user == "alexdsb@dsb.com" and pwd == "alex":  # 邮箱

                        login_dic["flag"] = True

                        login_dic["username"] = user

                        func(*args, **kwargs)

                    else:

                        print("用户名或密码错误!")



        return inner

    return wrapper

@auth("QQ")

def foo():

    print("这是一个被装饰的函数")



# wrapper = auth(chose)

# foo = wrapper(foo)

foo()

image-20190724175118645

多个装饰器装饰一个函数

def wrapper1(func):
    def inner1(*args,**kwargs):
        print(1)
        func(*args,**kwargs)
        print(11)
    return inner1
def wrapper2(func):
    def inner2(*args,**kwargs):
        func(*args,**kwargs)
        print(22)
    return inner2
def wrapper3(func):
    def inner3(*args,**kwargs):
        print(3)
        func(*args,**kwargs)
        print(33)
    return inner3
@wrapper1
@wrapper2
@wrapper3
def foo():
    print(8)

foo = wrapper2(foo)   # foo = inner2
foo = wrapper3(foo)   # inner3 = wrapper3(inner2)
foo = wrapper1(foo)   #inner1 = wrapper1(inner)
foo()
被装饰的函数正上方有多个装饰器,先执行离被装饰函数最近的装饰器


一开始是正着来,输出最后一行后然后反着来

先执行离被装饰的函数最近的语法糖
# 小技巧:进入装饰器从上往下,走到最会一个装饰器执行被装饰的函数,退出装饰器从下往上走

宝哥如是说
posted @ 2019-07-24 18:11  挂机兄  阅读(113)  评论(0编辑  收藏  举报