python 检查代理是否可以方法

# -*- coding: cp936 -*-
import urllib2,re,thread,time
import socket
socket.setdefaulttimeout(10)

def proxycheckone(proxy = '24.48.219.49:8080'):
    url='http://www.sohu.com'
    proxy_url = 'http://'+proxy
    proxy_support = urllib2.ProxyHandler({'http': proxy_url})
    httpHandler = urllib2.HTTPHandler(debuglevel=1)
    opener = urllib2.build_opener(proxy_support, httpHandler)
    r=urllib2.Request(url)
    r.add_header("Accept-Language","zh-cn")    #加入头信息，这样可以避免403错误
    r.add_header("Content-Type","text/html; charset=gb2312")
    r.add_header("User-Agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.1.4322)")
    trycount=1
    while trycount<=2:
        try:
            T0=time.time()
            f=opener.open(r)
            print time.time()-T0 
            data=f.read()
            if 'sohu' in data:
                T=time.time()-T0               
                break
            else:return []
        except:
            time.sleep(3)
            trycount=trycount+1
    if trycount>2:
        return []
    else:
        return proxy+'$'+str(trycount)+'#'+str(T)
    

proxycheckone()