黑猴子的家：子网掩码 与 IP 的关系

#! /usr/bin/env python
# -*- coding: utf-8 -*-
ip = input('请输入IP: ')
ips = ip.split('.')
for i in range(0,len(ips)):
    if i < len(ips) - 2:
        print(int(ips[i]) & 255, end='.')
    elif i < len(ips) - 1:
        print(int(ips[i]) & 255, end='.')
    else:
        print(int(ips[i]) & 0)