python检测QQ在线状态脚本

一段查询QQ是否在线的代码
通过访问http://wpa.qq.com/pa?p=1:[QQ号码]:1查询返回的图片
如果返回 2329 则在线  2262 则离线

import time,datetime  
import urllib2  
def chk_qq(qqnum):  
    chkurl = 'http://wpa.qq.com/pa?p=1:'+`qqnum`+':1'  
    a = urllib2.urlopen(chkurl)  
    length=a.headers.get("content-length")  
    a.close()  
    print datetime.datetime.now()  
    if length=='2329':  
        return 'Online'  
    elif length=='2262':  
        return 'Offline'  
    else:  
        return 'Unknown Status!'  
  
qq = 77199084  
stat = chk_qq(qq)  
print `qq` + ' is ' + stat