code: def sort_index(
          self,
          axis=0,
          level=None,
          ascending=True,
          inplace=False,
          kind="quicksort",
          na_position="last",
          sort_remaining=True,
          by=None,
      ):
          
          axis = self._get_axis_number(axis)
          if level is not None:
              new_query_compiler = self._default_to_pandas(
                  "sort_index",
                  axis=axis,
                  level=level,
                  ascending=ascending,
                  inplace=False,
                  kind=kind,
                  na_position=na_position,
                  sort_remaining=sort_remaining,
              )
              return self._create_or_update_from_compiler(new_query_compiler, inplace)
          if by is not None:
              warnings.warn(
                  "by argument to sort_index is deprecated, "
                  "please use .sort_values(by=...)",
                  FutureWarning,
                  stacklevel=2,
              )
              if level is not None:
                  raise ValueError("unable to simultaneously sort by and level")
              return self.sort_values(by, axis=axis, ascending=ascending, inplace=inplace)
          new_query_compiler = self._query_compiler.sort_index(
              axis=axis, ascending=ascending, kind=kind, na_position=na_position
          )
          if inplace:
              self._update_inplace(new_query_compiler=new_query_compiler)
          else:
              return self.__constructor__(query_compiler=new_query_compiler)
docs: Sort a DataFrame by one of the indices (columns or index).
  
          Args:
              axis: The axis to sort over.
              level: The MultiIndex level to sort over.
              ascending: Ascending or descending
              inplace: Whether or not to update this DataFrame inplace.
              kind: How to perform the sort.
              na_position: Where to position NA on the sort.
              sort_remaining: On Multilevel Index sort based on all levels.
              by: (Deprecated) argument to pass to sort_values.
  
          Returns:
              A sorted DataFrame