def get_cols_drag_value(self, cols):

        # if there is only one column in cols, then we return a 1-dimensional
        # list
        if len(cols) == 1:
            value = self.__get_data_column(cols[0])
        else:
            # iterate over every column, building a list of the values in that
            # column
            value = []
            for col in cols:
                value.append(self.__get_data_column(col))

        return value
Return the value to use when the specified columns are dragged or
dataset/ETHPy150Open enthought/pyface/pyface/ui/wx/grid/simple_grid_model.py/SimpleGridModel.get_cols_drag_value