text: #!/usr/bin/python2.7
  # -*- coding:utf-8 -*-
  
  # Author: NetworkRanger
  # Date: 2019/1/28 4:09 PM
  
  import requests
  
  class HtmlDownloader(object):
  
      def download(self,url):
          if url is None:
              return None
          user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
          headers = {'User-Agent': user_agent}
          r = requests.get(url, headers=headers)
          if r.status_code == 200:
              r.encoding = 'utf-8'
              return r.text
          return None
  