Python采集代理ip并判断是否可用和定时更新的方法

# -*- coding: utf-8 -*-import reimport urllib2import jsonimport osimport timeimport socketclass ProxyIp(object):  def __init__(self):    self.path = os.path.split(os.path.realpath(__file__))[0]  # Get latest proxy ip and download to json  def update_ip(self):    print 'Update Ip'    url = 'http://www.ip3366.net/free/'    req = urllib2.Request(url)    response = urllib2.urlopen(req)    matches = re.findall(      ur'(/d+./d+./d+./d+)</td>/s+<td>(/d+)</td>/s+<td>.*?</td>/s+<td>(HTTPS?)</td>',      response.read(),      re.I    )    ls = []    for match in matches:      if self.is_open(match[0], match[1]):        ls.append({'ip':match[0], 'port':match[1], 'protocol': match[2]})    with open('%s/ip.json' % self.path, 'w') as f:      json.dump(ls, f)    return ls  # whether the ips is last or old.  def is_last(self):    m_time = int(os.path.getmtime('%s/ip.json' % self.path))    now_time = int(time.time())    return (now_time - m_time) > 60*60*4 # 4 hours  @staticmethod  def is_open(ip, port):    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)    try:      s.connect(ip, int(port))      return True    except:      print 'Faild IP: %s:%s' % (ip, port)      return False  def get_proxy_ips(self):    if not self.is_last():      return self.update_ip()    else:      with open('%s/ip.json' % self.path, 'r') as f:        return json.load(f)