  class Number(models.Model):
      num = models.IntegerField()
  
      def __str__(self):
          return six.text_type(self.num)
  
  # Symmetrical m2m field with a normal field using the reverse accessor name
  # ("valid").
  
  
 
</s> remove         return six.text_type(self.name)
 </s> add         return self.name </s> remove         return six.text_type(self.name)
 </s> add         return self.name </s> remove         # Empty strings should be returned as Unicode
 </s> add         # Empty strings should be returned as string </s> remove         return "%s (%s)" % (self.revision, six.text_type(self.repository))
 </s> add         return "%s (%s)" % (self.revision, str(self.repository)) </s> remove         form_data['categories'] = [six.text_type(self.c1.id), six.text_type(self.c2.id)]
 </s> add         form_data['categories'] = [str(self.c1.id), str(self.c2.id)]
        return str(self.num)
  class Number(models.Model):
      num = models.IntegerField()
  
      def __str__(self):
        return str(self.num)
  
  # Symmetrical m2m field with a normal field using the reverse accessor name
  # ("valid").
  
  
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. 
tests/queries/models.py