Python访问纯真IP数据库脚本分享

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')