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')