          # Expression values are adapted by the database.
          if hasattr(value, 'resolve_expression'):
              return value
  
          if isinstance(value, six.string_types):
              return datetime.datetime.strptime(value, '%H:%M:%S')
  
          # Oracle doesn't support tz-aware times
          if timezone.is_aware(value):
              raise ValueError("Oracle backend does not support timezone-aware times.")
 
</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(value)
 </s> add         return str(value) </s> remove                         if hasattr(value, '__iter__') and not isinstance(value, six.text_type):
 </s> add                         if hasattr(value, '__iter__') and not isinstance(value, str):
        if isinstance(value, str):
          # Expression values are adapted by the database.
          if hasattr(value, 'resolve_expression'):
              return value
  
        if isinstance(value, str):
              return datetime.datetime.strptime(value, '%H:%M:%S')
  
          # Oracle doesn't support tz-aware times
          if timezone.is_aware(value):
              raise ValueError("Oracle backend does not support timezone-aware times.")
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/oracle/operations.py