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

import re

def is_a(domain):
    """递归直到获取到A记录IP"""
    if a_dict.has_key(domain):
        return a_dict[domain]
    else:
        return is_a(cname_dict[domain])

def handle(records):
    '''A记录和CNAME记录分为2个字典'''
    for line in records:
        record = re.split('\s',line.strip())
        if record[1].lower() == 'a':
            a_dict[record[0].lower()] = a_dict.get(record[0].lower(),[])
            a_dict[record[0].lower()].append(record[2])
            domain_list.append(record[0].lower())
        elif record[1].lower() == 'cname':
            cname_dict[record[0].lower()] = record[2].lower()
            domain_list.append(record[0].lower())
            domain_list.append(record[0].lower())

    domain_set = set(domain_list)  #建立一个唯一域名集合(去重)
    for i in domain_set:
        domain_dict[i] = domain_dict.get(i,is_a(i))
    print domain_dict



a_dict = {}
cname_dict = {}
domain_dict = {}
domain_list = []
records = open('record.txt','r')
handle(records)
records.close()