  class Transform(GeoFunc):
      def __init__(self, expression, srid, **extra):
          expressions = [
              expression,
              self._handle_param(srid, 'srid', six.integer_types),
          ]
          if 'output_field' not in extra:
              extra['output_field'] = GeometryField(srid=srid)
          super(Transform, self).__init__(*expressions, **extra)
  
 
</s> remove             self._handle_param(precision, 'precision', six.integer_types),
 </s> add             self._handle_param(precision, 'precision', int), </s> remove             expressions.append(self._handle_param(precision, 'precision', six.integer_types))
 </s> add             expressions.append(self._handle_param(precision, 'precision', int)) </s> remove             expressions.append(self._handle_param(precision, 'precision', six.integer_types))
 </s> add             expressions.append(self._handle_param(precision, 'precision', int)) </s> remove             expressions.append(self._handle_param(precision, 'precision', six.integer_types))
 </s> add             expressions.append(self._handle_param(precision, 'precision', int)) </s> remove                     ([six.text_type(self.author2)], [six.text_type(self.author3)]),
                    ([six.text_type(self.author3)], [six.text_type(self.author1)]),
                    ([six.text_type(self.author1)], [six.text_type(self.author2)])
 </s> add                     ([str(self.author2)], [str(self.author3)]),
                    ([str(self.author3)], [str(self.author1)]),
                    ([str(self.author1)], [str(self.author2)])
            self._handle_param(srid, 'srid', int),
  class Transform(GeoFunc):
      def __init__(self, expression, srid, **extra):
          expressions = [
              expression,
            self._handle_param(srid, 'srid', int),
          ]
          if 'output_field' not in extra:
              extra['output_field'] = GeometryField(srid=srid)
          super(Transform, self).__init__(*expressions, **extra)
  
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/db/models/functions.py