Add a diff column in percentage from a serie. The serie is 
        an iterable of the same length than the dataframe

        :param col: column to diff
        :type col: str
        :param serie: serie to diff from
        :type serie: iterable
        :param name: name of the diff col, defaults to "Diff"
        :param name: str, optional

        :example: ``ds.diffp("Col 1", [1, 1, 4], "New col")``

def diffsp(self, col: str, serie: "iterable", name: str="Diff"):
        """
        Add a diff column in percentage from a serie. The serie is 
        an iterable of the same length than the dataframe

        :param col: column to diff
        :type col: str
        :param serie: serie to diff from
        :type serie: iterable
        :param name: name of the diff col, defaults to "Diff"
        :param name: str, optional

        :example: ``ds.diffp("Col 1", [1, 1, 4], "New col")``
        """
        try:
            d = []
            for i, row in self.df.iterrows():
                v = (row[col]*100) / serie[i]
                d.append(v)
            self.df[name] = d
        except Exception as e:
            self.err(e, self._append, "Can not diff column from serie")