Sort object by labels (along an axis)

        Wrapper around the :meth:`pandas.DataFrame.sort_index` method.

def sort_index(self, axis=0, level=None, ascending=True, inplace=False,
                   kind='quicksort', na_position='last',
                   sort_remaining=True, by=None):
        """Sort object by labels (along an axis)

        Wrapper around the :meth:`pandas.DataFrame.sort_index` method.
        """
        return self._frame.sort_index(axis=axis, level=level,
                                      ascending=ascending, inplace=inplace,
                                      kind=kind, na_position=na_position,
                                      sort_remaining=sort_remaining, by=by)