Instance2:login interface

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# __author__ = "Deakin"
# Email: 469792427@qq.com
# Date: 2018/1/8

#模拟登陆：
#1. 用户输入帐号密码进行登陆
#2. 用户信息保存在文件内
#. 用户密码输入错误三次后锁定用户
f_lock=open("lock_list",'r+',encoding="utf-8")
f_account=open("account",'r',encoding="utf-8")
account = input("pls key in your account name:")
while True:
    for lockline in f_lock:
        lockline=lockline.strip('\n')
        if account==lockline:    
            print("your account has been locked, pls contact the system administrator")
            exit()
        else:
            pass
    for accountline in f_account:
        (user,passwd)=accountline.strip('\n').split() #分辨判断account password是否匹配
        if account==user:
            count=0
            while count<3:
                password=input("pls key in your password:")
                if password==passwd:
                    print("welcome to login,%s"%(account))
                    exit()
                else:
                    if count!=2:
                        print("your password is not correct,pls try again,remain %s times"%(2-count))
                    elif count==2:   #在第三次输错的时候不打印还剩几次机会
                        pass
                count+=1
            else:
                f_lock.write(account+'\n')
                print("your account has been locked,pls contact your system administrator")
                exit()
    else:
        print("account don't existed")
        break