python用户登录模块(不使用函数等方法)

*　　用户登录模块

给定用户信息表,需要满足条件如下:

1. 输入用户名密码判断

2. 输入错误次数3次时,询问用户是否需要继续尝试,Y继续,N结束

3. 可支持多用户登录

 1 # 方案一:输入用户名后立即判断一次,共三次
 2 li = [{‘username‘: ‘qqq‘, ‘password‘: ‘www‘},
 3       {‘username‘: ‘aaa‘, ‘password‘: ‘sss‘},
 4       {‘username‘: ‘zzz‘, ‘password‘: ‘xxx‘}]
 5
 6 # 将原列表转换为方便比较的新字典
 7 new_users_info = {}
 8 for i in li:
 9     new_users_info[i[‘username‘]] = i[‘password‘]
10
11 count_try_username, count_try_password = 0, 0  # 用户名尝试次数,密码尝试次数
12 flag_username, flag_password, flag_selection = 1, 1, 1  # 循环到用户名输入,循环到密码输入,循环到是否继续
13 while flag_username:
14     count_try_username += 1
15     username_input = input(‘请输入用户名:‘)
16     if username_input in new_users_info.keys():  # 判断用户名是否存在
17         count_try_password = 0  # 用户名尝试次数归零/或归1
18         flag_password, flag_selection = 1, 1  # 所有循环重新开始
19         while flag_password:
20             password_input = input(‘请输入密码:‘)
21             if password_input == new_users_info[username_input]:  # 判断密码是否与用户名匹配
22                 print(‘登录成功!跳转到APP使用页面‘)
23                 flag_username = 0
24                 break
25             else:
26                 count_try_password += 1
27                 print(‘密码输入错误...%s次‘ % count_try_password)
28                 if count_try_password == 3:
29                     while flag_selection:
30                         user_selection = input(‘是否继续?Y/N‘)
31                         user_selection = user_selection.lower()
32                         if user_selection == ‘y‘:
33                             count_try_username, count_try_password = 0, 0
34                             flag_password = 0
35                             flag_selection = 0
36                         elif user_selection == ‘n‘:
37                             flag_username = 0
38                             flag_password, flag_selection = 0, 0
39                             print(‘ByeBye...‘)
40                         else:
41                             print(‘错误选择‘)
42     else:
43         print(‘用户名输入错误...%s次‘ % count_try_username)
44         if count_try_username == 3:
45             flag_password, flag_selection = 1, 1  # 所有循环重新开始
46             while flag_selection:
47                 user_selection = input(‘是否继续?Y/N‘)
48                 user_selection = user_selection.lower()
49                 if user_selection == ‘y‘:
50                     count_try_username = 0
51                     flag_password = 0
52                     flag_selection = 0
53                 elif user_selection == ‘n‘:
54                     flag_username = 0
55                     flag_password, flag_selection = 0, 0
56                     print(‘ByeBye...‘)
57                 else:
58                     print(‘错误选择‘)

判断用户名是否正确

以上代码会判断用户名错误三次的情况.

以下代码不判断用户名错误,只判断匹配.

 1 # 用户登录(三次机会重试),可以支持多用户登录,三次后可选择Y/N决定是否继续尝试
 2 # 方案二:不判断用户名错误次数,只判断密码是否错误
 3 li = [{‘username‘: ‘li_alex‘, ‘password‘: ‘SB‘},
 4       {‘username‘: ‘wu_sir‘, ‘password‘: ‘sb‘},
 5       {‘username‘: ‘xu_jin‘, ‘password‘: ‘student‘}]
 6
 7 new_user_info = {}
 8 for user_info in li:
 9     new_user_info[user_info[‘username‘]] = user_info[‘password‘]
10 print(new_user_info)
11
12 while 1:
13     count = 0
14     username_entry = input(‘Please Input an Username: ‘)
15     if username_entry in new_user_info.keys():
16         password_entry = input(‘Please Input the Password: ‘)
17         while count < 2 and password_entry != new_user_info[username_entry]:
18             count += 1
19             print(‘Wrong Password Input, %d time(s) left...‘ % (3 - count))
20             password_entry = input(‘Please Input the Password: ‘)
21         else:
22             if password_entry == new_user_info[username_entry]:
23                 print(‘Congratulations! Login Succeed!‘)
24                 break
25             elif count > 1:
26                 user_selection = input(‘Invalid time Exceeds Limited, Do You Wanna Try Again? Y/N ‘)
27                 lower_entry = user_selection.lower()
28                 if lower_entry == ‘y‘:
29                     continue
30                 elif lower_entry == ‘n‘:
31                     print(‘You Give up Login attempt. Good luck...(手动微笑)‘)
32                     break
33                 else:
34                     print(‘Wrong Selection...Please Try Again...‘)
35                     continue
36             else:
37                 print("error")

判断用户名和密码匹配

均不使用函数等方法,只用while/for/if-else循环

原文地址：https://www.cnblogs.com/aliter/p/8821354.html