{

     'name': {'password': '', 'role': ''},

     'name2': {'password': '', 'role': ''},

     'name3': {'password': '', 'role': ''}

 }

 # 注册

 f = open('users.txt', 'a+', encoding='utf-8')

 f.seek(0)

 user_info = eval(f.read())# 字符串转字典

 i =0

 while i<3:

     i += 1

     uname = input("请输入用户名：").strip()

     upass = input("请输入密码：").strip()

     passC = input("请确认密码：").strip()

     if not uname or not upass or not passC:

         print("注册失败，用户名或密码不能为空")

         continue

     if upass != passC:

         print("注册失败，两次输入密码不一致")

         continue

     if uname in user_info:

         print("注册失败，用户名已存在")

         continue

     print("恭喜你，注册成功！")

     user_info[uname] ={'password':upass,'role':''}

     f.seek(0)

     f.truncate()

     f.write(str(user_info))

 else:

     print("sorry，register over 3 times bye-bye!")

 f.close()

 # 登录

 fr = open('users.txt', 'r')

 fr.seek(0)

 user_info = eval(fr.read())

 j = 0

 while j<3:

     j +=1

     uname = input("请输入用户名：\n").strip()

     upass = input("请输入密码：\n").strip()

     if not uname:

         print("用户名不能为空")

         continue

     if not upass:

         print("密码不能为空")

         continue

     if uname not in user_info:

         print("用户名不存在")

         continue

     if upass != user_info[uname]['password']:

         print("密码错误")

         continue

     print("恭喜你，登录成功！")

 else:

     print("sorry! login over 3 times bye-bye! ")

 f.close()