python 3次登录

 #!/usr/bin/env python
 #-*- encoding: utf- -*-

 import sys
 import os
 import getpass
 import platform

 # 全局变量
 retry_limit =         # 登录重试次数
 retry_count =         # 计数器

 account_file = 'account.txt'
 lock_file = 'account_lock.txt'

 def lock(user):
     lock_check = open(lock_file, 'r')        # 打开account_lock.txt，检查用户是否已经存在文件中

     for line in lock_check.readlines():    # 循环读取文件内容
         if user == line.strip('\n'):        # 去掉指定字符，并且判断是用户名是否和文件中的文件名一致
             sys.exit('\033[35mUser %s is locked!!!\033[0m' % user)    # 存在则直接退出并打印输出提示

     lock_check.close()        # 关闭打开的文件流

 def login(user, passwd):
     global retry_count        # 函数内要改变全局变量的值 "retry_count += 1"，需要加上global 关键字

     file = open(account_file, 'r')
     match_flag = False

     for line in file.readlines():
         username, password = line.strip('\n').split()

         if user == username and passwd == password:
             print 'hello, %s !!' % username
             match_flag = True
             break

     file.close()

     if match_flag == False:
         print 'sorry,%s is unmatched' % username
         retry_count +=
     else:
         print 'wlecome login my learning system!'
         sys.exit()

 def main():

     # 清屏操作，判断当前运行环境在什么平台下
     if platform.system() != 'Windows':
         os.system('clear')
     else:
         os.system('cls')

     while retry_count < retry_limit:
         username = raw_input('username: ')
         lock(username)
         password = getpass.getpass('password: ')    # 用getpass模块中的getpass方法来实现输入密码时和Linux一样
         login(username, password)
     else:
         print "you account %s is locked!!!" % username
         g = open(lock_file,'a')
         g.write(username)
         g.write('\n')
         g.close()

 if __name__ == '__main__':
     main()