          self._random_read = self.test_capability(b'RandomRead')
  
      def __getitem__(self, index):
          "Gets the Feature at the specified index."
          if isinstance(index, six.integer_types):
              # An integer index was given -- we cannot do a check based on the
              # number of features because the beginning and ending feature IDs
              # are not guaranteed to be 0 and len(layer)-1, respectively.
              if index < 0:
                  raise OGRIndexError('Negative indices are not allowed on OGR Layers.')
 
</s> remove         if isinstance(index, six.string_types):
 </s> add         if isinstance(index, str): </s> remove         if isinstance(index, six.string_types):
 </s> add         if isinstance(index, str): </s> remove         if not isinstance(index, six.integer_types + (slice,)):
 </s> add         if not isinstance(index, (int, slice)): </s> remove         if not isinstance(target, six.string_types) or not isinstance(index, int):
 </s> add         if not isinstance(target, str) or not isinstance(index, int): </s> remove         if not isinstance(index, (slice,) + six.integer_types):
 </s> add         if not isinstance(index, (int, slice)):
        if isinstance(index, int):
          self._random_read = self.test_capability(b'RandomRead')
  
      def __getitem__(self, index):
          "Gets the Feature at the specified index."
        if isinstance(index, int):
              # An integer index was given -- we cannot do a check based on the
              # number of features because the beginning and ending feature IDs
              # are not guaranteed to be 0 and len(layer)-1, respectively.
              if index < 0:
                  raise OGRIndexError('Negative indices are not allowed on OGR Layers.')
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
django/contrib/gis/gdal/layer.py