import time

current_user = {'user':None}

def auth(engine = "file")

    def deco(func):

        def wrapper(*args,**kwargs):

            if current_user['user']:

                #已经登录过

                    res = func（*args,**kwargs）

                    return res

            user = input("username>>>:").strip()

            pwd = input("password>>>:").strip()

            if engine == 'file':

                #基于文件的认证

                if user == “egon‘ and pwd == "123":

                    print('login successful')

                    current_user['user'] = user

                    res = func(*args,**kwargs)

                    return res

                else:

                    print('user or password error')

              elif engine == 'mysql':

                   print('基于MySQL的认证')

                      elif engine == 'mysql':

                print('基于MySQL的认证')

            elif engine == 'ldap':

                print('基于ldap的认证')

            else:

                print('无法识别认证来源')

        return wrapper

    return deco

@auth（engine = ”mysql“)

def index():

    print('welcome to index page')

    time.sleep(1)

index()