python编程练习

http://www.iplaypy.com/python-100/

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1.用户三次登陆机会，三次登录失败，验证码验证，验证成功继续三次登陆机会，验证失败退出。

代码：

 1 def vertified():
 2     import random
 3     temp = ""
 4     for i in range(6):
 5         num = random.randrange(0,4)
 6         if num ==2 or num == 4:
 7             rad_1 = random.randrange(0,10)
 8             temp  += str(rad_1)
 9         else:
10             rad_2 = random.randrange(65,91)
11             temp += chr(rad_2)
12     print(temp)
13     return temp
14 
15 
16 
17 def outer(func):
18     def inner():
19         time = 1
20         while True:
21             name = input('please input your id:')
22             key = input('key:')
23             if name == 'vae' and  key == '12345':
24                 print("登陆成功！")
25                 break
26             elif time == 3:
27                 ert = vertified()
28                 ret = input('check the verification code:' )
29                 if ret == ert:
30                     continue
31                 else:
32                     print('登陆失败！')
33                     break
34             else:
35                 print('再次尝试！')
36                 time += 1
37                 continue
38     return inner
39 
40 
41 @outer
42 def lock():
43     return 0
44 
45 lock()

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2.实现用户输入用户名和密码，程序在已有用户信息文件中检索，若一致则登陆成功！

 1 def login(username,pwd):
 2     s = open('s9.txt','r',encoding='utf-8')
 3     for line in s:
 4         generlize = line.strip()
 5         line_list = generlize.split('$')
 6         if username == line_list[0] and pwd == line_list[1]:
 7             return True
 8     return False
 9 
10 username = input('用户名：')
11 pwd = input('密码：')
12 
13 is_login = login(username,pwd)
14 if is_login :
15     print('login sucessfully!')
16 else:
17     print('login failly')

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3.用户登陆和注册（用户名占用or成功注册）

 1 def login(username,pwd):
 2     s = open('s9.txt','r',encoding='utf-8')
 3     for line in s:
 4         generlize = line.strip()
 5         line_list = generlize.split('$')
 6         if username == line_list[0] and pwd == line_list[1]:
 7             return True
 8     return False
 9 
10 def username_exist(username):
11     with open ('s9.txt','r',encoding = 'utf-8') as f:
12         for line in f:
13             generlization = line.strip()
14             line_list = generlization.split('$')
15             if line_list[0] == username:
16                 return True
17     return False
18 
19 def register(username,pwd):
20     with open('s9.txt','a',encoding = 'utf-8') as f:
21         temp = "
"+ username + "$" + pwd
22         f.write(temp)
23         f.close()
24 
25 def main():
26     print('欢迎登录**系统''
'
27           '1:登录；2:注册')
28     ret = input('您想要：')
29     if ret == "1":
30         username = input('用户名：')
31         pwd = input('密码：')
32         is_login = login(username, pwd)
33         if is_login:
34             print('login sucessfully!')
35 
36         else:
37             print('login failly')
38 
39     elif ret == "2":
40         username = input('用户名：')
41         pwd = input('密码：')
42         is_username = username_exist(username)
43         if is_username:
44             print('用户名被占用，注册失败')
45         else:
46             register(username, pwd)
47             print('注册成功！')
48 main()

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原文地址：https://www.cnblogs.com/hfdkd/p/8351877.html