          # MySQL doesn't support tz-aware times
          if timezone.is_aware(value):
              raise ValueError("MySQL backend does not support timezone-aware times.")
  
          return six.text_type(value)
  
      def max_name_length(self):
          return 64
  
      def bulk_insert_sql(self, fields, placeholder_rows):
 
</s> remove         if isinstance(value, six.string_types):
 </s> add         if isinstance(value, str): </s> remove         return six.text_type(value)
 </s> add         return str(value) </s> remove         return six.text_type(value)
 </s> add         return str(value) </s> remove         return six.text_type(value)
 </s> add         return str(value) </s> remove             return six.text_type(s).encode(encoding)
 </s> add             return str(s).encode(encoding)
        return str(value)
          # MySQL doesn't support tz-aware times
          if timezone.is_aware(value):
              raise ValueError("MySQL backend does not support timezone-aware times.")
  
        return str(value)
  
      def max_name_length(self):
          return 64
  
      def bulk_insert_sql(self, fields, placeholder_rows):
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/db/backends/mysql/operations.py