def get_group_for_col(self, table_name, col_name):
        """
        Check data model to find group name for a given column header

        Parameters
        ----------
        table_name: str
        col_name: str

        Returns
        ---------
        group_name: str
        """
        df = self.dm[table_name]
        try:
            group_name = df.loc[col_name, 'group']
        except KeyError:
            return ''
        return group_name