python二级登陆菜单

"""
 1.三级菜单 注册 登陆 注销
 2.进入每一个一级菜单，都会有下一级的菜单

"""
user_item = dict()
try:
    while true:
        print('-------welcome sir-------')
        input_choice = int(input('please enter your choice:1:registration 2:login 3:logout:'))
        # 用户输入自己的选择，会进入到相关的二级菜单
        if input_choice == 1:
            # if input_choice==1 进入注册
            user = input('please enter your account number:')
            pwd = input('please enter your password:')

            # 保存用户注册的账号
            user_item['user'] = user
            user_item['pwd'] = pwd
            # 提示用户注册成功
            print('您的账号已生效，下次请用该账号:{}登陆本系统'.format(user))

        # if input_choice==2 进入登陆
        elif input_choice == 2:
            login_user = input('please enter your login account number:')
            login_pwd = input('please enter your login password:')

            # 对用户输入的账号和密码进行确认
            if login_user == user_item['user'] and login_pwd == user_item['pwd']:
                print('welcome sir:{}'.format(login_user))
            else:
                print('sorry, your account or password is incorrect. please confirm and come back')
        # if input_choice == 3 进入注销
        elif input_choice == 3:
            logout_input = input('do you really want to quit this system?,y or n')
            if logout_input == 'y':
                break
            elif logout_input == 'n':
                input_choice = int(input('please enter your choice:1:registration 2:login 3:logout:'))
            else:
                print('your input is incorrect')
except exception as re:
    print(re)
finally:
    print('')