code: def list_of_list(self):
          
          ret = [[row.get(key, '') for key in self._col_names] for row in self]
          return ReprListList(ret, col_names=self._col_names,
                              col_types=self._col_types,
                              width_limit=self._width_limit,
                              digits=self._digits,
                              convert_unicode=self._convert_unicode)
docs: This will convert the data from a list of dict to a list of list
          :return: list of dict