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 = Falseip2int = 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')