Method swaplevel

pandas/core/indexes/multi.py:2894–2968

Swap level i with level j. Calling this method does not change the ordering of the values. Default is to swap the last two levels of the MultiIndex. Parameters ---------- i : int, str, default -2 First level of index to be swapped. Can

(self, i=-2, j=-1)

        return self[mask]

    def swaplevel(self, i=-2, j=-1) -> MultiIndex:
        """
        Swap level i with level j.

        Calling this method does not change the ordering of the values.

        Default is to swap the last two levels of the MultiIndex.

        Parameters
        ----------
        i : int, str, default -2
            First level of index to be swapped. Can pass level name as string.
            Type of parameters can be mixed. If i is a negative int, the first
            level is indexed relative to the end of the MultiIndex.
        j : int, str, default -1
            Second level of index to be swapped. Can pass level name as string.
            Type of parameters can be mixed. If j is a negative int, the second
            level is indexed relative to the end of the MultiIndex.

        Returns
        -------
        MultiIndex
            A new MultiIndex.

        See Also
        --------
        Series.swaplevel : Swap levels i and j in a MultiIndex.
        DataFrame.swaplevel : Swap levels i and j in a MultiIndex on a
            particular axis.

        Examples
        --------
        >>> mi = pd.MultiIndex(
        ...     levels=[["a", "b"], ["bb", "aa"], ["aaa", "bbb"]],
        ...     codes=[[0, 0, 1, 1], [0, 1, 0, 1], [1, 0, 1, 0]],
        ... )
        >>> mi
        MultiIndex([('a', 'bb', 'bbb'),
                    ('a', 'aa', 'aaa'),
                    ('b', 'bb', 'bbb'),
                    ('b', 'aa', 'aaa')],
                   )
        >>> mi.swaplevel()
        MultiIndex([('a', 'bbb', 'bb'),
                    ('a', 'aaa', 'aa'),
                    ('b', 'bbb', 'bb'),
                    ('b', 'aaa', 'aa')],
                   )
        >>> mi.swaplevel(0)
        MultiIndex([('bbb', 'bb', 'a'),
                    ('aaa', 'aa', 'a'),
                    ('bbb', 'bb', 'b'),
                    ('aaa', 'aa', 'b')],
                   )
        >>> mi.swaplevel(0, 1)
        MultiIndex([('bb', 'a', 'bbb'),
                    ('aa', 'a', 'aaa'),
                    ('bb', 'b', 'bbb'),