Add a column from the index

        :param col: name of the new column
        :type col: str

        :example: ``ds.index_col("New col")``

def indexcol(self, col: str):
        """
        Add a column from the index

        :param col: name of the new column
        :type col: str

        :example: ``ds.index_col("New col")``
        """
        try:
            self.df[col] = self.df.index.values
        except Exception as e:
            self.err(e)
            return
        self.ok("Column", col, "added from the index")