code: def _is_chapter_title(self, line):
          
          striped_line = line.strip()
          # 第X章
          if striped_line.startswith('第'):
              if 3 <= len(striped_line) < 30 and '章' in striped_line:
                  return True
          # "X." 或者 "X:"
          replaced_line = striped_line.replace(':', '.').replace('. ', '.')
          if replaced_line.split('.')[0].isdigit():
              if 3 <= len(replaced_line) < 20:
                  return True
          return False
docs: 检测是否章节标题
          :param line:
          :type line:
          :return:
          :rtype: