Python tweety api提供套接字错误

我是文本挖掘和python的新手。我正在尝试为我的项目从twitter收集数据，并尝试tweepy的一些程序。我从这里开始学习本教程

并尝试了这个例子

from tweepy import Stream
from tweepy import OAuthHandler
from tweepy.streaming import StreamListener

ckey='62iPwUDN82N6G78FE05P1b4bi'
csecret='CneDixa0FBubPgFpxuZoRPWi8RUcSuGIC9Gstjzf1hVzYDGuLa'
atoken='2506572247-3LcLGZvrfZ7bGVYF5ZoxkMEatrV7wn3R5Kbfrg8'
asecret='zzI73HDbtvZlWoR3sHyf6p3wQNCaRHGc1XC8ZqdZJH6QV'

class listener(StreamListener) :
    def on_data( self ,data) :
        print data
        return True

    def on_error( self ,status):

        print status



auth=OAuthHandler(ckey,csecret)
auth.set_access_token(atoken,asecret)

twitterStream=Stream(auth,listener())
twitterStream.filter(track=["car"])

但它给了我以下的错误

Traceback (most recent call last):
  File "f.py", line 24, in <module>
    twitterStream.filter(track=["car"])
  File "C:\Python27\lib\site-packages\tweepy-2.0-py2.7.egg\tweepy\streaming.py",
 line 230, in filter
    self._start(async)
  File "C:\Python27\lib\site-packages\tweepy-2.0-py2.7.egg\tweepy\streaming.py",
 line 171, in _start
    self._run()
  File "C:\Python27\lib\site-packages\tweepy-2.0-py2.7.egg\tweepy\streaming.py",
 line 106, in _run
    conn.connect()
  File "C:\Python27\lib\httplib.py", line 1172, in connect
    self.timeout, self.source_address)
  File "C:\Python27\lib\socket.py", line 571, in create_connection
    raise err
socket.error: [Errno 10051] A socket operation was attempted to an unreachable n
etwork

我没有使用python的ide，也没有在notepad++中编写它，而是在命令提示符下运行它。我正在使用windows7操作系统。我已安装tweepy 2.0

编辑：我在代理服务器后面不需要身份验证