#!/usr/bin/env python
# -*- coding: utf-8 -*-
count = 0
counttimes = 0
while counttimes < 3 : # 输入错误信息3次就锁定（终止循环）
    user = input('Please input your name:  ')
    pwd = input('Please input your password: ')
    if user == 'liuchao' and pwd == '123456':
        print ('welcome to beijing')
        break  #输入正确的用户名和密码显示欢迎信息并结束
        counttimes +=1 #counttimes = counttimes + 1 (输入错误时计数加1）
    else :
        counttimes +=1 #counttimes = counttimes + 1 (输入错误时计数加1）
        if count < 2 : #第三次输入错误后打印锁定提示不再显示再出输入
            count += 1
            print ('please enter again')
else :
    print ('You are not allowed to enter !!!') #锁定提示