code: def follower_num(self):
          
          href = re_collection_url_split.match(self.url).group(1)
          return int(self.soup.find('a', href=href + 'followers').text)
docs: 获取关注此收藏夹的人数.
  
          :return: 关注此收藏夹的人数
          :rtype: int