Method set

lib/sqlalchemy/orm/events.py:2757–2788

Receive a scalar set event. :param target: the object instance receiving the event. If the listener is registered with ``raw=True``, this will be the :class:`.InstanceState` object. :param value: the value being set. If this listener is registered with

(
        self, target: _O, value: _T, oldvalue: _T, initiator: Event
    )

        """

    def set(
        self, target: _O, value: _T, oldvalue: _T, initiator: Event
    ) -> None:
        """Receive a scalar set event.

        :param target: the object instance receiving the event.
          If the listener is registered with ``raw=True``, this will
          be the :class:`.InstanceState` object.
        :param value: the value being set.  If this listener
          is registered with ``retval=True``, the listener
          function must return this value, or a new value which
          replaces it.
        :param oldvalue: the previous value being replaced.  This
          may also be the symbol ``NEVER_SET`` or ``NO_VALUE``.
          If the listener is registered with ``active_history=True``,
          the previous value of the attribute will be loaded from
          the database if the existing value is currently unloaded
          or expired.
        :param initiator: An instance of :class:`.attributes.Event`
          representing the initiation of the event.  May be modified
          from its original value by backref handlers in order to control
          chained event propagation.

        :return: if the event was registered with ``retval=True``,
         the given value, or a new effective value, should be returned.

        .. seealso::

            :class:`.AttributeEvents` - background on listener options such
            as propagation to subclasses.

        """

    def init_scalar(
        self, target: _O, value: _T, dict_: Dict[Any, Any]