code: def _get_subinfo_list(self, keyword):
          
          res = self.session.get(
              self.API, params={'keyword': keyword, 'search_type': 'subtitle'})
          doc = res.content
          referer = res.url
          subinfo_list = self._parse_search_result_html(doc)
  
          return subinfo_list, referer
docs: 根据关键词搜索，返回字幕信息列表