code: def comments(self):
          
          import math
          from .author import Author, ANONYMOUS
          from .comment import Comment
  
          api_url = Get_Answer_Comment_URL.format(self.aid)
          page = pages = 1
          while page <= pages:
              res = self._session.get(api_url + '?page=' + str(page))
              if page == 1:
                  total = int(res.json()['paging']['totalCount'])
                  if total == 0:
                      return
                  pages = math.ceil(total / 30) 
              page += 1
  
              comment_items = res.json()['data']
              for comment_item in comment_items:
                  comment_id = comment_item['id']
                  content = comment_item['content']
                  upvote_num = comment_item['likesCount']
                  time_string = comment_item['createdTime'][:19]
                  time = datetime.strptime(time_string, "%Y-%m-%dT%H:%M:%S")
  
                  if comment_item['author'].get('url') is not None:
                      a_url = comment_item['author']['url']
                      a_name = comment_item['author']['name']
                      photo_url_tmp = comment_item['author']['avatar']['template']
                      photo_url_id = comment_item['author']['avatar']['id']
                      a_photo_url = photo_url_tmp.replace(
                              '{id}', photo_url_id).replace('_{size}', '')
                      author_obj = Author(a_url, a_name, photo_url=a_photo_url,
                                          session=self._session)
                  else:
                      author_obj = ANONYMOUS
  
                  yield Comment(comment_id, self, author_obj, upvote_num, content, time)
docs: 获取答案下的所有评论.
  
          :return: 答案下的所有评论，返回生成器
          :rtype: Comments.Iterable