1.基本需求

编写登陆接口，实现如下需求：

（1）输入用户名密码

（2）认证成功后显示欢迎信息

（3）输错三次后锁定

2.实现细节

·每添加一个用户，需要手动添加三个文件

·注：username是指该用户的用户名，视具体的用户名而定；

·每添加一个用户，在username.txt中写入该用户名，一个用户名占一行（手动）；

·如果输入的用户名或密码为空，都要求重新输入；

·输入不存在的用户名，只会提示“username or password wrong”；

·输入存在的用户名，才会进行密码输入错误次数的记录。

3.实现代码与注释

import sys,oscount = 0  #To count, if the user is locked.
mark_user = 0   #To make sure if the user is existing.
mark_passwd = 0 #To make sure if the password is right.while count < 3:name = raw_input('Username:').strip()if len(name) == 0:print 'The username can not be empty!'continuekey = raw_input('Password:').strip() if len(key) == 0:print 'The password can not be empty!Try again!'continue#Upon:To check if the username or password is empty.检查用户名或密码是否为空f = file('username.txt', 'r')userlist = f.readlines()f.close()for user in userlist:if user.strip() == name:mark_user = 1#检查输入的用户是否在username.txt文件中，即是否注册，如果在，mark_user = 1if mark_user == 1:  f = file('%s_lock.txt' % (name), 'r')locked = int(f.readline().strip())f.close()  else:print 'Username or password wrong!'  break
#Upon:To check if exist,if not exist,printing username or password wrong!And quit the program.
#用户名不存在就提示用户名或密码错误，用户名存在就检查该用户是否被锁定if locked == 1:sys.exit('Sorry, the username had been locked!!!Please call the system administrator.')#Upon:To check if the username is locked by the system.else:f = file('%s_passwd.txt' % (name), 'r')passwd = (f.readline().strip())if passwd.strip() == key:mark_passwd = 1# check the password from the name_input password file.if mark_user == 1 and mark_passwd == 1:f = file('%s_count.txt' % name, 'w')f.write('0')f.close()sys.exit('%s, welcome to our system!' % name)#用户名和密码正确，将username_count.txt内容重置为0 else:f = file('%s_count.txt' % name, 'r')count = int((f.read().strip()))f.close()count += 1f = file('%s_count.txt' % name, 'w')f.write(str(count))f.close()#open the count file of the user and change it.
#密码不正确，就把count次数记录在该用户名对应的文件count文件上print '''Username or password wrong!
And the username '%s' has %d more chances to retry!''' % (name, 3 - count)if count == 3:print "'%s' has been locked!!!" % (name)if os.path.exists('%s_lock.txt' % (name)):fobj = open('%s_lock.txt' % (name), 'w')fobj.writelines('1\n')else:print 'Username or password wrong!'continue#Upon:To check if the username and password are right, if not, the count will add 1.
#如果count次数为3，则将用户对应的lock文件内容重置为1，锁定该用户

4.测试

--对单一用户xpleaf的测试

·在对应4个文件中添加相应信息：

xpleaf@xpleaf-machine:~/seminar6/day1$ head username.txt xpleaf_count.txt xpleaf_lock.txt xpleaf_passwd.txt
==> username.txt <==
xpleaf==> xpleaf_count.txt <==
0
==> xpleaf_lock.txt <==
0==> xpleaf_passwd.txt <==
xpleaf123

·正常输入用户名和密码：

xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:xpleaf
Password:xpleaf123
xpleaf, welcome to our system!

·故意输错两次密码后查看相关文件：

xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:xpleaf
Password:klkdf
Username or password wrong!
And the username 'xpleaf' has 2 more chances to retry!
Username:xpleaf
Password:kldf
Username or password wrong!
And the username 'xpleaf' has 1 more chances to retry!
Username:Traceback (most recent call last):File "newlogin.py", line 8, in <module>name = raw_input('Username:').strip()
EOFError
xpleaf@xpleaf-machine:~/seminar6/day1$ cat xpleaf_count.txt
2

·可以看到count文件已经记录为2，再输入正确的用户名和密码：

xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:xpleaf
Password:xpleaf123
xpleaf, welcome to our system!
xpleaf@xpleaf-machine:~/seminar6/day1$ cat xpleaf_count.txt
0

·count文件重置为0；

·连续输入密码错误超过3次：

0xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:xpleaf
Password:kldf
Username or password wrong!
And the username 'xpleaf' has 2 more chances to retry!
Username:xpleaf
Password:klkdf
Username or password wrong!
And the username 'xpleaf' has 1 more chances to retry!
Username:xpleaf
Password:kldf
Username or password wrong!
And the username 'xpleaf' has 0 more chances to retry!
'xpleaf' has been locked!!!
xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:xpleaf
Password:xpleaf123
Sorry, the username had been locked!!!Please call the system administrator.
xpleaf@xpleaf-machine:~/seminar6/day1$ cat xpleaf_lock.txt
1

·用户已经被锁定，对应lock文件内容变为1，如果需要解锁，则要手动将该文件重置为0；

·输入错误的用户名：

xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:klkdlf
Password:klkdf
Username or password wrong!

·只会提示用户名或密码错误，不会做相关文件记录；

--对两个用户xpleaf和yonghaoyip的测试

·为用户yonghaoyip添加相关文件信息：

xpleaf@xpleaf-machine:~/seminar6/day1$ head username.txt yonghaoyip_count.txt yonghaoyip_lock.txt yonghaoyip_passwd.txt
==> username.txt <==
xpleaf
yonghaoyip==> yonghaoyip_count.txt <==
0==> yonghaoyip_lock.txt <==
0==> yonghaoyip_passwd.txt <==
yonghaoyip123

·主要测试两个用户的count文件记录：

对用户yonghaoyip操作：
xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:yonghaoyip
Password:klkdf
Username or password wrong!
And the username 'yonghaoyip' has 2 more chances to retry!
Username:yonghaoyip
Password:kldf
Username or password wrong!
And the username 'yonghaoyip' has 1 more chances to retry!
Username:Traceback (most recent call last):File "newlogin.py", line 8, in <module>name = raw_input('Username:').strip()
EOFError对用户xpleaf操作：
xpleaf@xpleaf-machine:~/seminar6/day1$ python newlogin.py
Username:xpleaf
Password:kkjlkdf
Username or password wrong!
And the username 'xpleaf' has 2 more chances to retry!
Username:xpleaf
Password:xpleaf123
xpleaf, welcome to our system!查看两个用户对应的count文件记录：
xpleaf@xpleaf-machine:~/seminar6/day1$ head yonghaoyip_count.txt xpleaf_count.txt
==> yonghaoyip_count.txt <==
2
==> xpleaf_count.txt <==
0

·可以看到两个用户的相关文件并不会相互影响。