简单文件操作

 1 #!/usr/bin/env python
 2 # -*- encoding:utf-8 -*-
 3 def login(username, password):
 4     """
 5     login
 6     :param username: username
 7     :param password: password
 8     :return: True,login success,False,login fail
 9     """
10     with open('db', 'r', encoding='utf-8') as f:
11         for line in f:
12             line = line.strip()
13             list = line.split("$$")
14             if username == list[0] and password == list[1]:
15                 return True
16     return False
17 
18 
19 def exist(username):
20     """
21     check exist
22     :param username: username
23     :return: True,exist,    False, not exist
24     """
25     with open("db", "r", encoding="utf-8") as f:
26         for line in f:
27             line = line.strip()
28             line_list = line.split("$$")
29             if username == line_list[0]:
30                 return True
31     return False
32 
33 
34 def register(username, password):
35     """
36     注册
37     :param username: 用户名
38     :param password: 密码
39     :return: 
40     """
41     f = open('db', 'a', encoding='utf-8')
42     string = "\n" + username + "$$" + password
43     f.write(string)
44     return True
45 
46 
47 def updatePwd(username, oldPwd, newPwd):
48     """
49     修改密码
50     :param username: 用户民
51     :param oldPwd: 旧密码
52     :param newPwd: 新密码
53     :return: True 修改成功， F，修改失败
54     """
55     with open('db', 'r', encoding='utf-8') as  f:
56         lines = f.readlines()
57     with open('db', 'w', encoding='utf-8') as  w:
58         for line in lines:
59             if username in line:
60                 line = line.replace(oldPwd, newPwd)
61             w.write(line)
62         return True
63     return False
64 
65 
66 while True:
67     print('welcome to login xxx system')
68     select = input('1.login=====2.register')
69     if select == '1':
70         username = input("username:")
71         password = input("password:")
72         if login(username, password):
73             print('login success!')
74             select = input("1.updatePwd")
75             if select == '1':
76                 newPwd = input("input new password:")
77                 if updatePwd(username, password, newPwd):
78                     print("udpate success!")
79                 else:
80                     print("update fail!")
81         else:
82             print('login failed!')
83     else:
84         username = input("username:")
85         password = input("password:")
86         if exist(username):
87             print("username has existed!")
88         elif register(username, password):
89             print("register success!")
posted on 2018-01-16 22:08 jovelove 阅读(106) 评论(0) 收藏举报