登入验证（3次）

#!/usr/bin/env python
# -*- coding:utf-8 -*-

'''
#要求验证，最多可以尝试3次。3错误后可以按"Y"继续尝试3次，或者按"N"退出
#提示输入
user = input('请输入用户名：')
pwd = input('请输入密码：')
if user == 'xiaozhang' and pwd  == 'xiaozhang123':
    print('登入成功')
else:
    print("登入失败")


#三次机会
count = 1
while count <= 3:
    print(count)
    count += 1
'''

#--------------------------功能嵌套------------------------------
count = 1
while count <= 3:
    print('第%d次输入'%count)
    user = input('请输入用户名：')
    pwd = input('请输入密码：')
    if user == 'xiaozhang' and pwd == 'xiaozhang123':
        print('登入成功')
        break
    else:
        print("登入失败")
        if  count == 3:
            choice = input("请输入是否继续（Y/N）：")
            if choice =='Y':
                count = 1
                continue
            elif choice == 'N':
                break
            else:
                break

    count += 1