题解 | #识别有效的IP地址和掩码并进行分类统计#

排坑，未判断子网掩码如果不足8位需要补足的情况，新代码用例全部通过

比较复杂，需要考虑为None和''情况下的数据转换情况

需要验证ip和mask的合法性

需要识别ip的类型

最大的坑是如果ip是属于忽略的，那么mask即使是错误的，也需要按照忽略取处理

看我的代码会发现主函数中有忽略，在识别ip中又有忽略类型的返回就是一开始没有注意到上面的坑

其中ip使用逻辑判断，mask使用re模块的正则匹配是最简单，利用bin函数转换隔断数字为二进制并且拼接后匹配正则

import re
import sys


def valid_none(value):
    if value is None or value == '':
        return False
    else:
        return True


def valid_ip(ip):
    sub_ip_list = list(filter(valid_none, [x for x in ip.split('.')]))
    sub_ip_list = [int(x) for x in sub_ip_list]
    if len(sub_ip_list) != 4:
        return False
    elif sub_ip_list[0] > 255 or sub_ip_list[0] < 1:
        return False
    else:
        for sub_ip in sub_ip_list[1:]:
            if sub_ip > 255 or sub_ip < 0:
                return False
    return True


def valid_mask(mask):
    sub_mask_list = [int(x) for x in mask.split('.')]
    if len(sub_mask_list) != 4:
        return False
    mask_string = ''
    for x in sub_mask_list:
        bin_ip_str = str(bin(x))[2:]
        mask_string += '0'*(8-len(bin_ip_str)) + bin_ip_str
    pattern = re.compile('^[1]{1,32}[0]{1,32}$')
    if pattern.search(mask_string):
        return True
    else:
        return False


def judge_public_ip_type(ip):
    first_ip = int(ip.split('.')[0])
    if 1 <= first_ip <= 126:
        return 'A'
    elif 128 <= first_ip <= 191:
        return 'B'
    elif 192 <= first_ip <= 223:
        return 'C'
    elif 224 <= first_ip <= 239:
        return 'D'
    elif 240 <= first_ip <= 255:
        return 'E'
    elif first_ip == 0 or first_ip == 127:
        return 'IGNORE'


def judge_private_ip_type(ip):
    sub_ip_list = [int(x) for x in ip.split('.')]
    first_ip, second_ip = sub_ip_list[0], sub_ip_list[1]
    if first_ip == 10:
        return True
    elif first_ip == 172 and 16 <= second_ip <= 31:
        return True
    elif first_ip == 192 and second_ip == 168:
        return True
    return False


if __name__ == '__main__':
    A, B, C, D, E, ERROR, PRIVATE = 0, 0, 0, 0, 0, 0, 0
    ip_mask_list = sys.stdin
    for ip_mask in ip_mask_list:
        ip, mask = ip_mask.strip().split('~')
        if ip.startswith('0.') or ip.startswith('127.'):
            pass
        elif valid_ip(ip) and valid_mask(mask):
            ip_type = judge_public_ip_type(ip)
            if ip_type == 'A':
                A += 1
            elif ip_type == 'B':
                B += 1
            elif ip_type == 'C':
                C += 1
            elif ip_type == 'D':
                D += 1
            elif ip_type == 'E':
                E += 1
            else:
                pass
            if judge_private_ip_type(ip):
                PRIVATE += 1
        else:
            ERROR += 1
    print(A, B, C, D, E, ERROR, PRIVATE)
    
    ```