code: def serial_fetch(self, stock_no, month, twse=None):
          
          result = ()
          self.__get_mons = month
          self.__get_no = stock_no
          self._twse = twse
          for i in range(month):
              nowdatetime = datetime.today() - relativedelta(months=i)
              tolist = self.to_list(self.fetch_data(stock_no, nowdatetime))
              result = tolist + result
          return tuple(result)
docs: 串接每月資料 舊→新
  
              :param str stock_no: 股票代碼
              :param int month: 擷取 n 個月的資料
              :param bool twse: 指定是否為上市資料
              :rtype: tuple