python实现二级登陆菜单及安装过程

""" 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('')