Method sortlevel

pandas/core/indexes/base.py:2157–2201

For internal compatibility with the Index API. Sort the Index. This is for compat with MultiIndex Parameters ---------- ascending : bool, default True False to sort in descending order na_position : {'first' or 'last'}, default 'first'

(
        self,
        level=None,
        ascending: bool | list[bool] = True,
        sort_remaining=None,
        na_position: NaPosition = "first",
    )

        return 0

    def sortlevel(
        self,
        level=None,
        ascending: bool | list[bool] = True,
        sort_remaining=None,
        na_position: NaPosition = "first",
    ) -> tuple[Self, np.ndarray]:
        """
        For internal compatibility with the Index API.

        Sort the Index. This is for compat with MultiIndex

        Parameters
        ----------
        ascending : bool, default True
            False to sort in descending order
        na_position : {'first' or 'last'}, default 'first'
            Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at
            the end.

            .. versionadded:: 2.1.0

        level, sort_remaining are compat parameters

        Returns
        -------
        Index
        """
        if not isinstance(ascending, (list, bool)):
            raise TypeError(
                "ascending must be a single bool value or"
                "a list of bool values of length 1"
            )

        if isinstance(ascending, list):
            if len(ascending) != 1:
                raise TypeError("ascending must be a list of bool values of length 1")
            ascending = ascending[0]

        if not isinstance(ascending, bool):
            raise TypeError("ascending must be a bool value")

        return self.sort_values(
            return_indexer=True, ascending=ascending, na_position=na_position
        )

    def _get_level_values(self, level) -> Index:
        """