项目中有这样的需求，通过IP地址判断客户端是网通的还是电信的。从同事那拿了个纯文本的IP纯真数据库，用Python写了一个小程序，感觉挺好的。下面给出实现源码：

#!/usr/bin/env python

# -*- coding: utf-8 -*-

from bisect import bisect

_LIST1, _LIST2 = [], []

_INIT = False

ip2int = lambda ip_str: reduce(lambda a, b: (a << 8) + b, [int(i) for i in ip_str.split('.')])

def _init():

global _LIST, _INIT

if not _INIT:

for l in open('ipdata.txt', 'rb'):

ip1, ip2 = l.split()[:2]

addr = ' '.join(l.split()[2:])

ip1, ip2 = ip2int(ip1), ip2int(ip2)

_LIST1.append(ip1)

_LIST2.append((ip1, ip2, addr))

_INIT = True

def ip_from(ip):

_init()

i = ip2int(ip)

idx = bisect(_LIST1, i)

assert(idx > 0)

if len(_LIST1) <= idx:

return u'unknown ip address %s' % ip

else:

frm, to ,addr = _LIST2[idx - 1]

if frm <= i <= to:

return addr

else:

return u'unknown ip address %s' % ip

if __name__ == '__main__':

print ip_from('115.238.54.106')

print ip_from('220.181.29.160')

print ip_from('115.238.54.107')

print ip_from('8.8.8.8')