Python-用户登录三次错误锁定

黑名单：blacklist.txt

用户名单：username_password.py

 # Author:Stephen Yuan

 # 用户名和密码
 username_password = {
     'stephen': '',
     'alex': '',
     'sara': ''
 }

主程序：main.py

 # Author: Stephen Yuan
 import username_password
 # import blacklist

 username_password = username_password.username_password
 print(username_password)

 count = 0
 while True:
     with open('blacklist.txt', 'r', encoding='utf-8') as blacklist:
         blacklist = blacklist.read().split()
         print(blacklist, type(blacklist))
     username = input("请输入用户名：")
     if username in blacklist:
         print("您的用户名已被锁定，请联系管理员！")
     elif username in username_password.keys():
         for i in range(3):
             userpass = input("请输入密码：")
             if userpass == username_password[username]:
                 print("登录成功")
                 exit()
             else:
                 print("密码错误，请重新输入！")
                 count += 1
             if count == 3:
                 with open('blacklist.txt', 'a', encoding='utf-8') as blacklist2:
                     blacklist2.write(username + ' ')
                     print(blacklist)
                     print("当前的用户已经被锁定，请联系管理员！")
     else:
         print("用户名不存在，请重新输入！")