      headline: Poker has no place on ESPN
      pub_date: 2006-06-16 11:00:00
      categories: [%(first_category_pk)s, %(second_category_pk)s]
  """
  
      @staticmethod
      def _validate_output(serial_str):
 
</s> remove     pass
 </s> add     @classmethod
    def WithData(cls, original_exc, model, fk, field_value):
        """
        Factory method for creating a deserialization error which has a more
        explanatory messsage.
        """
        return cls("%s: (%s:pk=%s) field_value was '%s'" % (original_exc, model, fk, field_value)) </s> remove     ]
 </s> add     ],
    "meta_data": [] </s> remove                             value = field.remote_field.model._meta.get_field(field.remote_field.field_name).to_python(field_value)
                        data[field.attname] = value
                    else:
                        data[field.attname] = field.remote_field.model._meta.get_field(field.remote_field.field_name).to_python(field_value)
 </s> add                             data[field.attname] = field.remote_field.model._meta.get_field(field.remote_field.field_name).to_python(field_value)
                    except Exception as e:
                        raise base.DeserializationError.WithData(e, d['model'], d.get('pk'), field_value)
    meta_data: []
      headline: Poker has no place on ESPN
      pub_date: 2006-06-16 11:00:00
      categories: [%(first_category_pk)s, %(second_category_pk)s]
    meta_data: []
  """
  
      @staticmethod
      def _validate_output(serial_str):
keep keep add keep keep keep keep
 Fixed #19820 -- Added more helpful error messages to Python deserializer. 
tests/serializers/tests.py