urllib2连接超时设置

#urllib2设置超时
#获取网页的源码
def getHtml(url,i):
    if i > 2:
        return
    try:
        req = urllib2.Request(url)
        time.sleep(1)
        req.add_header('User-Agent', 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.87 Safari/537.36')
        page = urllib2.urlopen(req,timeout = 3).read()
    except socket.error:
        getHtml(url,i+1)
    except:
        return
    return page