def sort_values(self, by, ascending=True):
        """Summary

        Returns:
            TYPE: Description
        """
        if len(self.column_types) == 1:
            vec_type = [WeldVec(self.column_types[0])]
        else:
            vec_type = [WeldVec(WeldStruct(self.column_types))]

        if len(self.column_names) > 1:
            key_index = self.column_names.index(by)
        else :
            key_index = None

        return GroupedDataFrameWeld(
            grizzly_impl.groupby_sort(
                self.columns,
                self.column_types,
                self.grouping_columns,
                self.grouping_column_types,
                key_index,
                ascending
            ),
            self.grouping_column_names,
            self.column_names,
            self.grouping_column_types,
            vec_type
        )