认证功能装饰器

# _*_ coding: utf-8 _*_
import time

def auth(func):
    # func = index原始的内存地址
    # 相当于这里有个func = index
        # print('welcome to index page')
        # time.sleep(3)
    def wrapper(*args,**kwargs):
        inp_usr = input('please input your username: ').strip()
        inp_pwd = input('please input your password: ').strip()
        if inp_usr == 'ooc' and inp_pwd == '123':
            print('login successful')
            res=func(*args,**kwargs) # 没有参数，
            # 在auth----wrapper中找到func=index
            return res# index中无返回值 所以返回None
        else:
            print('username or password error')
    return wrapper#返回wrapper的函数的内存地址

@auth #index = auth(index) index=wrapper
def index():
    print('welcome to index page')
    time.sleep(3)

res = index() #wrapper()
print(res) #无返回值所以返回None