1.1

 1 # -*- coding: utf-8 -*-
 2 # 基础需求
 3 """
 4 让用户输入用户名密码
 5 认证成功后显示欢迎信息
 6 输错三次退出程序
 7 """
 8 _username = "alice"
 9 _password = "123"
10 count = 0
11 
12 while count < 3:
13     username = input("Username:")
14     password = input("Password:")
15     if username == _username and password == _password:
16         print("登录成功！")
17         break
18     else:
19         print("登录失败！")
20     count += 1

 1 # -*- coding: utf-8 -*-
 2 # 升级需求
 3 """
 4 可以支持多个用户登录
 5 用户3次认证失败后，退出程序，再次启动程序尝试登录时，是锁定状态
 6 需把锁定状态存到文件中
 7 """
 8 import os
 9 _listname = ['alice', 'alex', 'lily']
10 _password = "123"
11 count = 0
12 while count < 3:
13     if os.path.exists('lock_file.txt'):
14         f = open('lock_file.txt', 'r', encoding='utf-8')
15         if '3次' in f.read():
16             print('用户已锁定')
17             f.close()
18             break
19     username = input("Username:")
20     password = input("Password:")
21     if password == _password:
22         if not username in _listname:
23             print("登录失败！")
24         else:
25             print("登录成功！")
26             break
27     else:
28         print("登录失败！")
29     count += 1
30 else:
31     print('失败', '次数', '3次', sep='->', end='
', file=open('lock_file.txt', 'w', encoding='utf-8'))