Method fget

lib/sqlalchemy/orm/descriptor_props.py:283–308

(instance: Any)

        """

        def fget(instance: Any) -> Any:
            dict_ = attributes.instance_dict(instance)
            state = attributes.instance_state(instance)

            if self.key not in dict_:
                # key not present.  Iterate through related
                # attributes, retrieve their values.  This
                # ensures they all load.
                values = [
                    getattr(instance, key) for key in self._attribute_keys
                ]

                # current expected behavior here is that the composite is
                # created on access if the object is persistent or if
                # col attributes have non-None.  This would be better
                # if the composite were created unconditionally,
                # but that would be a behavioral change.
                if self.key not in dict_ and (
                    state.key is not None or not _none_set.issuperset(values)
                ):
                    dict_[self.key] = self.composite_class(*values)
                    state.manager.dispatch.refresh(
                        state, self._COMPOSITE_FGET, [self.key]
                    )

            return dict_.get(self.key, None)

        def fset(instance: Any, value: Any) -> None:
            dict_ = attributes.instance_dict(instance)