在网上看到的别人写的python2的代码，修改成了python3。

把纯真IP数据库文件qqwry.dat放到czip.py同一目录下。

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# filename: czip.py


import socket
import struct


class CzIp:
    def __init__(self, db_file='qqwry.dat'):
        self.f_db = open(db_file, "rb")
        bs = self.f_db.read(8)
        (self.first_index, self.last_index) = struct.unpack('II', bs)
        self.index_count = int((self.last_index - self.first_index) / 7 + 1)
        self.cur_start_ip = None
        self.cur_end_ip_offset = None
        self.cur_end_ip = None
        # print(self.get_version(), " 纪录总数: %d 条 "%(self.index_count))

    def get_version(self):
        '''
        获取版本信息，最后一条IP记录 255.255.255.0-255.255.255.255 是版本信息
        :return: str
        '''
        s = self.get_addr_by_ip(0xffffff00)
        return s

    def _get_area_addr(self, offset=0):
        if offset:
            self.f_db.seek(offset)
        bs = self.f_db.read(1)
        (byte,) = struct.unpack('B', bs)
        if byte == 0x01 or byte == 0x02:
            p = self.getLong3()
            if p:
                return self.get_offset_string(p)
            else:
                return ""
        else:
            self.f_db.seek(-1, 1)
            return self.get_offset_string(offset)

    def _get_addr(self, offset):
        '''
        获取offset处记录区地址信息(包含国家和地区)
        如果是中国ip，则是 "xx省xx市 xxxxx地区" 这样的形式
        (比如:"福建省 电信", "澳大利亚 墨尔本Goldenit有限公司")
        :param offset:
        :return:str
        '''
        self.f_db.seek(offset + 4)
        bs = self.f_db.read(1)
        (byte,) = struct.unpack('B', bs)
        if byte == 0x01:    # 重定向模式1
            country_offset = self.getLong3()
            self.f_db.seek(country_offset)
            bs = self.f_db.read(1)
            (b,) = struct.unpack('B', bs)
            if b == 0x02:   
                country_addr = self.get_offset_string(self.getLong3())
                self.f_db.seek(country_offset + 4)
            else:   
                country_addr = self.get_offset_string(country_offset)
            area_addr = self._get_area_addr()
        elif byte == 0x02:  # 重定向模式2
            country_addr = self.get_offset_string(self.getLong3())
            area_addr = self._get_area_addr(offset + 8)
        else:   # 字符串模式
            country_addr = self.get_offset_string(offset + 4)
            area_addr = self._get_area_addr()
        return country_addr + " " + area_addr

    def dump(self, first, last):
        '''
        打印数据库中索引为first到索引为last(不包含last)的记录
        :param first:
        :param last:
        :return:
        '''
        if last > self.index_count:
            last = self.index_count
        for index in range(first, last):
            offset = self.first_index + index * 7
            self.f_db.seek(offset)
            buf = self.f_db.read(7)
            (ip, of1, of2) = struct.unpack("IHB", buf)
            address = self._get_addr(of1 + (of2 << 16))
            print("%d %s %s" % (index, self.ip2str(ip), address))

    def _set_ip_range(self, index):
        offset = self.first_index + index * 7
        self.f_db.seek(offset)
        buf = self.f_db.read(7)
        (self.cur_start_ip, of1, of2) = struct.unpack("IHB", buf)
        self.cur_end_ip_offset = of1 + (of2 << 16)
        self.f_db.seek(self.cur_end_ip_offset)
        buf = self.f_db.read(4)
        (self.cur_end_ip,) = struct.unpack("I", buf)

    def get_addr_by_ip(self, ip):
        '''
        通过ip查找其地址
        :param ip: (int or str)
        :return: str
        '''
        if type(ip) == str:
            ip = self.str2ip(ip)
        L = 0
        R = self.index_count - 1
        while L <