urlopen windows ftp error

This code works perfectly at linux, but windows at there are errors. What's wrong?

import urllib, urllib2

a = 'ftp://ftp.arin.net/pub/stats/arin/delegated-arin-latest'

urllib.urlopen(a)
IOError: [开发者_开发技巧Errno ftp error] proxy support for ftp protocol currently not implemented

urllib2.urlopen(a)
URLError: <urlopen error ftp error: >

Check if you have some proxy settings in your Internet Explorer: Menu Extras->Internet Options, there Connections->"LAN settings" (or something similar). If you have a Proxy server setting, urllib will not work.