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diff --git a/.venv/lib/python3.12/site-packages/sqlalchemy/orm/events.py b/.venv/lib/python3.12/site-packages/sqlalchemy/orm/events.py
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+# orm/events.py
+# Copyright (C) 2005-2025 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+"""ORM event interfaces.
+
+"""
+from __future__ import annotations
+
+from typing import Any
+from typing import Callable
+from typing import Collection
+from typing import Dict
+from typing import Generic
+from typing import Iterable
+from typing import Optional
+from typing import Sequence
+from typing import Set
+from typing import Type
+from typing import TYPE_CHECKING
+from typing import TypeVar
+from typing import Union
+import weakref
+
+from . import instrumentation
+from . import interfaces
+from . import mapperlib
+from .attributes import QueryableAttribute
+from .base import _mapper_or_none
+from .base import NO_KEY
+from .instrumentation import ClassManager
+from .instrumentation import InstrumentationFactory
+from .query import BulkDelete
+from .query import BulkUpdate
+from .query import Query
+from .scoping import scoped_session
+from .session import Session
+from .session import sessionmaker
+from .. import event
+from .. import exc
+from .. import util
+from ..event import EventTarget
+from ..event.registry import _ET
+from ..util.compat import inspect_getfullargspec
+
+if TYPE_CHECKING:
+    from weakref import ReferenceType
+
+    from ._typing import _InstanceDict
+    from ._typing import _InternalEntityType
+    from ._typing import _O
+    from ._typing import _T
+    from .attributes import Event
+    from .base import EventConstants
+    from .session import ORMExecuteState
+    from .session import SessionTransaction
+    from .unitofwork import UOWTransaction
+    from ..engine import Connection
+    from ..event.base import _Dispatch
+    from ..event.base import _HasEventsDispatch
+    from ..event.registry import _EventKey
+    from ..orm.collections import CollectionAdapter
+    from ..orm.context import QueryContext
+    from ..orm.decl_api import DeclarativeAttributeIntercept
+    from ..orm.decl_api import DeclarativeMeta
+    from ..orm.mapper import Mapper
+    from ..orm.state import InstanceState
+
+_KT = TypeVar("_KT", bound=Any)
+_ET2 = TypeVar("_ET2", bound=EventTarget)
+
+
+class InstrumentationEvents(event.Events[InstrumentationFactory]):
+    """Events related to class instrumentation events.
+
+    The listeners here support being established against
+    any new style class, that is any object that is a subclass
+    of 'type'.  Events will then be fired off for events
+    against that class.  If the "propagate=True" flag is passed
+    to event.listen(), the event will fire off for subclasses
+    of that class as well.
+
+    The Python ``type`` builtin is also accepted as a target,
+    which when used has the effect of events being emitted
+    for all classes.
+
+    Note the "propagate" flag here is defaulted to ``True``,
+    unlike the other class level events where it defaults
+    to ``False``.  This means that new subclasses will also
+    be the subject of these events, when a listener
+    is established on a superclass.
+
+    """
+
+    _target_class_doc = "SomeBaseClass"
+    _dispatch_target = InstrumentationFactory
+
+    @classmethod
+    def _accept_with(
+        cls,
+        target: Union[
+            InstrumentationFactory,
+            Type[InstrumentationFactory],
+        ],
+        identifier: str,
+    ) -> Optional[
+        Union[
+            InstrumentationFactory,
+            Type[InstrumentationFactory],
+        ]
+    ]:
+        if isinstance(target, type):
+            return _InstrumentationEventsHold(target)  # type: ignore [return-value] # noqa: E501
+        else:
+            return None
+
+    @classmethod
+    def _listen(
+        cls, event_key: _EventKey[_T], propagate: bool = True, **kw: Any
+    ) -> None:
+        target, identifier, fn = (
+            event_key.dispatch_target,
+            event_key.identifier,
+            event_key._listen_fn,
+        )
+
+        def listen(target_cls: type, *arg: Any) -> Optional[Any]:
+            listen_cls = target()
+
+            # if weakref were collected, however this is not something
+            # that normally happens.   it was occurring during test teardown
+            # between mapper/registry/instrumentation_manager, however this
+            # interaction was changed to not rely upon the event system.
+            if listen_cls is None:
+                return None
+
+            if propagate and issubclass(target_cls, listen_cls):
+                return fn(target_cls, *arg)
+            elif not propagate and target_cls is listen_cls:
+                return fn(target_cls, *arg)
+            else:
+                return None
+
+        def remove(ref: ReferenceType[_T]) -> None:
+            key = event.registry._EventKey(  # type: ignore [type-var]
+                None,
+                identifier,
+                listen,
+                instrumentation._instrumentation_factory,
+            )
+            getattr(
+                instrumentation._instrumentation_factory.dispatch, identifier
+            ).remove(key)
+
+        target = weakref.ref(target.class_, remove)
+
+        event_key.with_dispatch_target(
+            instrumentation._instrumentation_factory
+        ).with_wrapper(listen).base_listen(**kw)
+
+    @classmethod
+    def _clear(cls) -> None:
+        super()._clear()
+        instrumentation._instrumentation_factory.dispatch._clear()
+
+    def class_instrument(self, cls: ClassManager[_O]) -> None:
+        """Called after the given class is instrumented.
+
+        To get at the :class:`.ClassManager`, use
+        :func:`.manager_of_class`.
+
+        """
+
+    def class_uninstrument(self, cls: ClassManager[_O]) -> None:
+        """Called before the given class is uninstrumented.
+
+        To get at the :class:`.ClassManager`, use
+        :func:`.manager_of_class`.
+
+        """
+
+    def attribute_instrument(
+        self, cls: ClassManager[_O], key: _KT, inst: _O
+    ) -> None:
+        """Called when an attribute is instrumented."""
+
+
+class _InstrumentationEventsHold:
+    """temporary marker object used to transfer from _accept_with() to
+    _listen() on the InstrumentationEvents class.
+
+    """
+
+    def __init__(self, class_: type) -> None:
+        self.class_ = class_
+
+    dispatch = event.dispatcher(InstrumentationEvents)
+
+
+class InstanceEvents(event.Events[ClassManager[Any]]):
+    """Define events specific to object lifecycle.
+
+    e.g.::
+
+        from sqlalchemy import event
+
+
+        def my_load_listener(target, context):
+            print("on load!")
+
+
+        event.listen(SomeClass, "load", my_load_listener)
+
+    Available targets include:
+
+    * mapped classes
+    * unmapped superclasses of mapped or to-be-mapped classes
+      (using the ``propagate=True`` flag)
+    * :class:`_orm.Mapper` objects
+    * the :class:`_orm.Mapper` class itself indicates listening for all
+      mappers.
+
+    Instance events are closely related to mapper events, but
+    are more specific to the instance and its instrumentation,
+    rather than its system of persistence.
+
+    When using :class:`.InstanceEvents`, several modifiers are
+    available to the :func:`.event.listen` function.
+
+    :param propagate=False: When True, the event listener should
+       be applied to all inheriting classes as well as the
+       class which is the target of this listener.
+    :param raw=False: When True, the "target" argument passed
+       to applicable event listener functions will be the
+       instance's :class:`.InstanceState` management
+       object, rather than the mapped instance itself.
+    :param restore_load_context=False: Applies to the
+       :meth:`.InstanceEvents.load` and :meth:`.InstanceEvents.refresh`
+       events.  Restores the loader context of the object when the event
+       hook is complete, so that ongoing eager load operations continue
+       to target the object appropriately.  A warning is emitted if the
+       object is moved to a new loader context from within one of these
+       events if this flag is not set.
+
+       .. versionadded:: 1.3.14
+
+
+    """
+
+    _target_class_doc = "SomeClass"
+
+    _dispatch_target = ClassManager
+
+    @classmethod
+    def _new_classmanager_instance(
+        cls,
+        class_: Union[DeclarativeAttributeIntercept, DeclarativeMeta, type],
+        classmanager: ClassManager[_O],
+    ) -> None:
+        _InstanceEventsHold.populate(class_, classmanager)
+
+    @classmethod
+    @util.preload_module("sqlalchemy.orm")
+    def _accept_with(
+        cls,
+        target: Union[
+            ClassManager[Any],
+            Type[ClassManager[Any]],
+        ],
+        identifier: str,
+    ) -> Optional[Union[ClassManager[Any], Type[ClassManager[Any]]]]:
+        orm = util.preloaded.orm
+
+        if isinstance(target, ClassManager):
+            return target
+        elif isinstance(target, mapperlib.Mapper):
+            return target.class_manager
+        elif target is orm.mapper:  # type: ignore [attr-defined]
+            util.warn_deprecated(
+                "The `sqlalchemy.orm.mapper()` symbol is deprecated and "
+                "will be removed in a future release. For the mapper-wide "
+                "event target, use the 'sqlalchemy.orm.Mapper' class.",
+                "2.0",
+            )
+            return ClassManager
+        elif isinstance(target, type):
+            if issubclass(target, mapperlib.Mapper):
+                return ClassManager
+            else:
+                manager = instrumentation.opt_manager_of_class(target)
+                if manager:
+                    return manager
+                else:
+                    return _InstanceEventsHold(target)  # type: ignore [return-value] # noqa: E501
+        return None
+
+    @classmethod
+    def _listen(
+        cls,
+        event_key: _EventKey[ClassManager[Any]],
+        raw: bool = False,
+        propagate: bool = False,
+        restore_load_context: bool = False,
+        **kw: Any,
+    ) -> None:
+        target, fn = (event_key.dispatch_target, event_key._listen_fn)
+
+        if not raw or restore_load_context:
+
+            def wrap(
+                state: InstanceState[_O], *arg: Any, **kw: Any
+            ) -> Optional[Any]:
+                if not raw:
+                    target: Any = state.obj()
+                else:
+                    target = state
+                if restore_load_context:
+                    runid = state.runid
+                try:
+                    return fn(target, *arg, **kw)
+                finally:
+                    if restore_load_context:
+                        state.runid = runid
+
+            event_key = event_key.with_wrapper(wrap)
+
+        event_key.base_listen(propagate=propagate, **kw)
+
+        if propagate:
+            for mgr in target.subclass_managers(True):
+                event_key.with_dispatch_target(mgr).base_listen(propagate=True)
+
+    @classmethod
+    def _clear(cls) -> None:
+        super()._clear()
+        _InstanceEventsHold._clear()
+
+    def first_init(self, manager: ClassManager[_O], cls: Type[_O]) -> None:
+        """Called when the first instance of a particular mapping is called.
+
+        This event is called when the ``__init__`` method of a class
+        is called the first time for that particular class.    The event
+        invokes before ``__init__`` actually proceeds as well as before
+        the :meth:`.InstanceEvents.init` event is invoked.
+
+        """
+
+    def init(self, target: _O, args: Any, kwargs: Any) -> None:
+        """Receive an instance when its constructor is called.
+
+        This method is only called during a userland construction of
+        an object, in conjunction with the object's constructor, e.g.
+        its ``__init__`` method.  It is not called when an object is
+        loaded from the database; see the :meth:`.InstanceEvents.load`
+        event in order to intercept a database load.
+
+        The event is called before the actual ``__init__`` constructor
+        of the object is called.  The ``kwargs`` dictionary may be
+        modified in-place in order to affect what is passed to
+        ``__init__``.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param args: positional arguments passed to the ``__init__`` method.
+         This is passed as a tuple and is currently immutable.
+        :param kwargs: keyword arguments passed to the ``__init__`` method.
+         This structure *can* be altered in place.
+
+        .. seealso::
+
+            :meth:`.InstanceEvents.init_failure`
+
+            :meth:`.InstanceEvents.load`
+
+        """
+
+    def init_failure(self, target: _O, args: Any, kwargs: Any) -> None:
+        """Receive an instance when its constructor has been called,
+        and raised an exception.
+
+        This method is only called during a userland construction of
+        an object, in conjunction with the object's constructor, e.g.
+        its ``__init__`` method. It is not called when an object is loaded
+        from the database.
+
+        The event is invoked after an exception raised by the ``__init__``
+        method is caught.  After the event
+        is invoked, the original exception is re-raised outwards, so that
+        the construction of the object still raises an exception.   The
+        actual exception and stack trace raised should be present in
+        ``sys.exc_info()``.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param args: positional arguments that were passed to the ``__init__``
+         method.
+        :param kwargs: keyword arguments that were passed to the ``__init__``
+         method.
+
+        .. seealso::
+
+            :meth:`.InstanceEvents.init`
+
+            :meth:`.InstanceEvents.load`
+
+        """
+
+    def _sa_event_merge_wo_load(
+        self, target: _O, context: QueryContext
+    ) -> None:
+        """receive an object instance after it was the subject of a merge()
+        call, when load=False was passed.
+
+        The target would be the already-loaded object in the Session which
+        would have had its attributes overwritten by the incoming object. This
+        overwrite operation does not use attribute events, instead just
+        populating dict directly. Therefore the purpose of this event is so
+        that extensions like sqlalchemy.ext.mutable know that object state has
+        changed and incoming state needs to be set up for "parents" etc.
+
+        This functionality is acceptable to be made public in a later release.
+
+        .. versionadded:: 1.4.41
+
+        """
+
+    def load(self, target: _O, context: QueryContext) -> None:
+        """Receive an object instance after it has been created via
+        ``__new__``, and after initial attribute population has
+        occurred.
+
+        This typically occurs when the instance is created based on
+        incoming result rows, and is only called once for that
+        instance's lifetime.
+
+        .. warning::
+
+            During a result-row load, this event is invoked when the
+            first row received for this instance is processed.  When using
+            eager loading with collection-oriented attributes, the additional
+            rows that are to be loaded / processed in order to load subsequent
+            collection items have not occurred yet.   This has the effect
+            both that collections will not be fully loaded, as well as that
+            if an operation occurs within this event handler that emits
+            another database load operation for the object, the "loading
+            context" for the object can change and interfere with the
+            existing eager loaders still in progress.
+
+            Examples of what can cause the "loading context" to change within
+            the event handler include, but are not necessarily limited to:
+
+            * accessing deferred attributes that weren't part of the row,
+              will trigger an "undefer" operation and refresh the object
+
+            * accessing attributes on a joined-inheritance subclass that
+              weren't part of the row, will trigger a refresh operation.
+
+            As of SQLAlchemy 1.3.14, a warning is emitted when this occurs. The
+            :paramref:`.InstanceEvents.restore_load_context` option may  be
+            used on the event to prevent this warning; this will ensure that
+            the existing loading context is maintained for the object after the
+            event is called::
+
+                @event.listens_for(SomeClass, "load", restore_load_context=True)
+                def on_load(instance, context):
+                    instance.some_unloaded_attribute
+
+            .. versionchanged:: 1.3.14 Added
+               :paramref:`.InstanceEvents.restore_load_context`
+               and :paramref:`.SessionEvents.restore_load_context` flags which
+               apply to "on load" events, which will ensure that the loading
+               context for an object is restored when the event hook is
+               complete; a warning is emitted if the load context of the object
+               changes without this flag being set.
+
+
+        The :meth:`.InstanceEvents.load` event is also available in a
+        class-method decorator format called :func:`_orm.reconstructor`.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param context: the :class:`.QueryContext` corresponding to the
+         current :class:`_query.Query` in progress.  This argument may be
+         ``None`` if the load does not correspond to a :class:`_query.Query`,
+         such as during :meth:`.Session.merge`.
+
+        .. seealso::
+
+            :ref:`mapped_class_load_events`
+
+            :meth:`.InstanceEvents.init`
+
+            :meth:`.InstanceEvents.refresh`
+
+            :meth:`.SessionEvents.loaded_as_persistent`
+
+        """  # noqa: E501
+
+    def refresh(
+        self, target: _O, context: QueryContext, attrs: Optional[Iterable[str]]
+    ) -> None:
+        """Receive an object instance after one or more attributes have
+        been refreshed from a query.
+
+        Contrast this to the :meth:`.InstanceEvents.load` method, which
+        is invoked when the object is first loaded from a query.
+
+        .. note:: This event is invoked within the loader process before
+           eager loaders may have been completed, and the object's state may
+           not be complete.  Additionally, invoking row-level refresh
+           operations on the object will place the object into a new loader
+           context, interfering with the existing load context.   See the note
+           on :meth:`.InstanceEvents.load` for background on making use of the
+           :paramref:`.InstanceEvents.restore_load_context` parameter, in
+           order to resolve this scenario.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param context: the :class:`.QueryContext` corresponding to the
+         current :class:`_query.Query` in progress.
+        :param attrs: sequence of attribute names which
+         were populated, or None if all column-mapped, non-deferred
+         attributes were populated.
+
+        .. seealso::
+
+            :ref:`mapped_class_load_events`
+
+            :meth:`.InstanceEvents.load`
+
+        """
+
+    def refresh_flush(
+        self,
+        target: _O,
+        flush_context: UOWTransaction,
+        attrs: Optional[Iterable[str]],
+    ) -> None:
+        """Receive an object instance after one or more attributes that
+        contain a column-level default or onupdate handler have been refreshed
+        during persistence of the object's state.
+
+        This event is the same as :meth:`.InstanceEvents.refresh` except
+        it is invoked within the unit of work flush process, and includes
+        only non-primary-key columns that have column level default or
+        onupdate handlers, including Python callables as well as server side
+        defaults and triggers which may be fetched via the RETURNING clause.
+
+        .. note::
+
+            While the :meth:`.InstanceEvents.refresh_flush` event is triggered
+            for an object that was INSERTed as well as for an object that was
+            UPDATEd, the event is geared primarily  towards the UPDATE process;
+            it is mostly an internal artifact that INSERT actions can also
+            trigger this event, and note that **primary key columns for an
+            INSERTed row are explicitly omitted** from this event.  In order to
+            intercept the newly INSERTed state of an object, the
+            :meth:`.SessionEvents.pending_to_persistent` and
+            :meth:`.MapperEvents.after_insert` are better choices.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param flush_context: Internal :class:`.UOWTransaction` object
+         which handles the details of the flush.
+        :param attrs: sequence of attribute names which
+         were populated.
+
+        .. seealso::
+
+            :ref:`mapped_class_load_events`
+
+            :ref:`orm_server_defaults`
+
+            :ref:`metadata_defaults_toplevel`
+
+        """
+
+    def expire(self, target: _O, attrs: Optional[Iterable[str]]) -> None:
+        """Receive an object instance after its attributes or some subset
+        have been expired.
+
+        'keys' is a list of attribute names.  If None, the entire
+        state was expired.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param attrs: sequence of attribute
+         names which were expired, or None if all attributes were
+         expired.
+
+        """
+
+    def pickle(self, target: _O, state_dict: _InstanceDict) -> None:
+        """Receive an object instance when its associated state is
+        being pickled.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param state_dict: the dictionary returned by
+         :class:`.InstanceState.__getstate__`, containing the state
+         to be pickled.
+
+        """
+
+    def unpickle(self, target: _O, state_dict: _InstanceDict) -> None:
+        """Receive an object instance after its associated state has
+        been unpickled.
+
+        :param target: the mapped instance.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :param state_dict: the dictionary sent to
+         :class:`.InstanceState.__setstate__`, containing the state
+         dictionary which was pickled.
+
+        """
+
+
+class _EventsHold(event.RefCollection[_ET]):
+    """Hold onto listeners against unmapped, uninstrumented classes.
+
+    Establish _listen() for that class' mapper/instrumentation when
+    those objects are created for that class.
+
+    """
+
+    all_holds: weakref.WeakKeyDictionary[Any, Any]
+
+    def __init__(
+        self,
+        class_: Union[DeclarativeAttributeIntercept, DeclarativeMeta, type],
+    ) -> None:
+        self.class_ = class_
+
+    @classmethod
+    def _clear(cls) -> None:
+        cls.all_holds.clear()
+
+    class HoldEvents(Generic[_ET2]):
+        _dispatch_target: Optional[Type[_ET2]] = None
+
+        @classmethod
+        def _listen(
+            cls,
+            event_key: _EventKey[_ET2],
+            raw: bool = False,
+            propagate: bool = False,
+            retval: bool = False,
+            **kw: Any,
+        ) -> None:
+            target = event_key.dispatch_target
+
+            if target.class_ in target.all_holds:
+                collection = target.all_holds[target.class_]
+            else:
+                collection = target.all_holds[target.class_] = {}
+
+            event.registry._stored_in_collection(event_key, target)
+            collection[event_key._key] = (
+                event_key,
+                raw,
+                propagate,
+                retval,
+                kw,
+            )
+
+            if propagate:
+                stack = list(target.class_.__subclasses__())
+                while stack:
+                    subclass = stack.pop(0)
+                    stack.extend(subclass.__subclasses__())
+                    subject = target.resolve(subclass)
+                    if subject is not None:
+                        # we are already going through __subclasses__()
+                        # so leave generic propagate flag False
+                        event_key.with_dispatch_target(subject).listen(
+                            raw=raw, propagate=False, retval=retval, **kw
+                        )
+
+    def remove(self, event_key: _EventKey[_ET]) -> None:
+        target = event_key.dispatch_target
+
+        if isinstance(target, _EventsHold):
+            collection = target.all_holds[target.class_]
+            del collection[event_key._key]
+
+    @classmethod
+    def populate(
+        cls,
+        class_: Union[DeclarativeAttributeIntercept, DeclarativeMeta, type],
+        subject: Union[ClassManager[_O], Mapper[_O]],
+    ) -> None:
+        for subclass in class_.__mro__:
+            if subclass in cls.all_holds:
+                collection = cls.all_holds[subclass]
+                for (
+                    event_key,
+                    raw,
+                    propagate,
+                    retval,
+                    kw,
+                ) in collection.values():
+                    if propagate or subclass is class_:
+                        # since we can't be sure in what order different
+                        # classes in a hierarchy are triggered with
+                        # populate(), we rely upon _EventsHold for all event
+                        # assignment, instead of using the generic propagate
+                        # flag.
+                        event_key.with_dispatch_target(subject).listen(
+                            raw=raw, propagate=False, retval=retval, **kw
+                        )
+
+
+class _InstanceEventsHold(_EventsHold[_ET]):
+    all_holds: weakref.WeakKeyDictionary[Any, Any] = (
+        weakref.WeakKeyDictionary()
+    )
+
+    def resolve(self, class_: Type[_O]) -> Optional[ClassManager[_O]]:
+        return instrumentation.opt_manager_of_class(class_)
+
+    class HoldInstanceEvents(_EventsHold.HoldEvents[_ET], InstanceEvents):  # type: ignore [misc] # noqa: E501
+        pass
+
+    dispatch = event.dispatcher(HoldInstanceEvents)
+
+
+class MapperEvents(event.Events[mapperlib.Mapper[Any]]):
+    """Define events specific to mappings.
+
+    e.g.::
+
+        from sqlalchemy import event
+
+
+        def my_before_insert_listener(mapper, connection, target):
+            # execute a stored procedure upon INSERT,
+            # apply the value to the row to be inserted
+            target.calculated_value = connection.execute(
+                text("select my_special_function(%d)" % target.special_number)
+            ).scalar()
+
+
+        # associate the listener function with SomeClass,
+        # to execute during the "before_insert" hook
+        event.listen(SomeClass, "before_insert", my_before_insert_listener)
+
+    Available targets include:
+
+    * mapped classes
+    * unmapped superclasses of mapped or to-be-mapped classes
+      (using the ``propagate=True`` flag)
+    * :class:`_orm.Mapper` objects
+    * the :class:`_orm.Mapper` class itself indicates listening for all
+      mappers.
+
+    Mapper events provide hooks into critical sections of the
+    mapper, including those related to object instrumentation,
+    object loading, and object persistence. In particular, the
+    persistence methods :meth:`~.MapperEvents.before_insert`,
+    and :meth:`~.MapperEvents.before_update` are popular
+    places to augment the state being persisted - however, these
+    methods operate with several significant restrictions. The
+    user is encouraged to evaluate the
+    :meth:`.SessionEvents.before_flush` and
+    :meth:`.SessionEvents.after_flush` methods as more
+    flexible and user-friendly hooks in which to apply
+    additional database state during a flush.
+
+    When using :class:`.MapperEvents`, several modifiers are
+    available to the :func:`.event.listen` function.
+
+    :param propagate=False: When True, the event listener should
+       be applied to all inheriting mappers and/or the mappers of
+       inheriting classes, as well as any
+       mapper which is the target of this listener.
+    :param raw=False: When True, the "target" argument passed
+       to applicable event listener functions will be the
+       instance's :class:`.InstanceState` management
+       object, rather than the mapped instance itself.
+    :param retval=False: when True, the user-defined event function
+       must have a return value, the purpose of which is either to
+       control subsequent event propagation, or to otherwise alter
+       the operation in progress by the mapper.   Possible return
+       values are:
+
+       * ``sqlalchemy.orm.interfaces.EXT_CONTINUE`` - continue event
+         processing normally.
+       * ``sqlalchemy.orm.interfaces.EXT_STOP`` - cancel all subsequent
+         event handlers in the chain.
+       * other values - the return value specified by specific listeners.
+
+    """
+
+    _target_class_doc = "SomeClass"
+    _dispatch_target = mapperlib.Mapper
+
+    @classmethod
+    def _new_mapper_instance(
+        cls,
+        class_: Union[DeclarativeAttributeIntercept, DeclarativeMeta, type],
+        mapper: Mapper[_O],
+    ) -> None:
+        _MapperEventsHold.populate(class_, mapper)
+
+    @classmethod
+    @util.preload_module("sqlalchemy.orm")
+    def _accept_with(
+        cls,
+        target: Union[mapperlib.Mapper[Any], Type[mapperlib.Mapper[Any]]],
+        identifier: str,
+    ) -> Optional[Union[mapperlib.Mapper[Any], Type[mapperlib.Mapper[Any]]]]:
+        orm = util.preloaded.orm
+
+        if target is orm.mapper:  # type: ignore [attr-defined]
+            util.warn_deprecated(
+                "The `sqlalchemy.orm.mapper()` symbol is deprecated and "
+                "will be removed in a future release. For the mapper-wide "
+                "event target, use the 'sqlalchemy.orm.Mapper' class.",
+                "2.0",
+            )
+            return mapperlib.Mapper
+        elif isinstance(target, type):
+            if issubclass(target, mapperlib.Mapper):
+                return target
+            else:
+                mapper = _mapper_or_none(target)
+                if mapper is not None:
+                    return mapper
+                else:
+                    return _MapperEventsHold(target)
+        else:
+            return target
+
+    @classmethod
+    def _listen(
+        cls,
+        event_key: _EventKey[_ET],
+        raw: bool = False,
+        retval: bool = False,
+        propagate: bool = False,
+        **kw: Any,
+    ) -> None:
+        target, identifier, fn = (
+            event_key.dispatch_target,
+            event_key.identifier,
+            event_key._listen_fn,
+        )
+
+        if (
+            identifier in ("before_configured", "after_configured")
+            and target is not mapperlib.Mapper
+        ):
+            util.warn(
+                "'before_configured' and 'after_configured' ORM events "
+                "only invoke with the Mapper class "
+                "as the target."
+            )
+
+        if not raw or not retval:
+            if not raw:
+                meth = getattr(cls, identifier)
+                try:
+                    target_index = (
+                        inspect_getfullargspec(meth)[0].index("target") - 1
+                    )
+                except ValueError:
+                    target_index = None
+
+            def wrap(*arg: Any, **kw: Any) -> Any:
+                if not raw and target_index is not None:
+                    arg = list(arg)  # type: ignore [assignment]
+                    arg[target_index] = arg[target_index].obj()  # type: ignore [index] # noqa: E501
+                if not retval:
+                    fn(*arg, **kw)
+                    return interfaces.EXT_CONTINUE
+                else:
+                    return fn(*arg, **kw)
+
+            event_key = event_key.with_wrapper(wrap)
+
+        if propagate:
+            for mapper in target.self_and_descendants:
+                event_key.with_dispatch_target(mapper).base_listen(
+                    propagate=True, **kw
+                )
+        else:
+            event_key.base_listen(**kw)
+
+    @classmethod
+    def _clear(cls) -> None:
+        super()._clear()
+        _MapperEventsHold._clear()
+
+    def instrument_class(self, mapper: Mapper[_O], class_: Type[_O]) -> None:
+        r"""Receive a class when the mapper is first constructed,
+        before instrumentation is applied to the mapped class.
+
+        This event is the earliest phase of mapper construction.
+        Most attributes of the mapper are not yet initialized.   To
+        receive an event within initial mapper construction where basic
+        state is available such as the :attr:`_orm.Mapper.attrs` collection,
+        the :meth:`_orm.MapperEvents.after_mapper_constructed` event may
+        be a better choice.
+
+        This listener can either be applied to the :class:`_orm.Mapper`
+        class overall, or to any un-mapped class which serves as a base
+        for classes that will be mapped (using the ``propagate=True`` flag)::
+
+            Base = declarative_base()
+
+
+            @event.listens_for(Base, "instrument_class", propagate=True)
+            def on_new_class(mapper, cls_):
+                "..."
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param class\_: the mapped class.
+
+        .. seealso::
+
+            :meth:`_orm.MapperEvents.after_mapper_constructed`
+
+        """
+
+    def after_mapper_constructed(
+        self, mapper: Mapper[_O], class_: Type[_O]
+    ) -> None:
+        """Receive a class and mapper when the :class:`_orm.Mapper` has been
+        fully constructed.
+
+        This event is called after the initial constructor for
+        :class:`_orm.Mapper` completes.  This occurs after the
+        :meth:`_orm.MapperEvents.instrument_class` event and after the
+        :class:`_orm.Mapper` has done an initial pass of its arguments
+        to generate its collection of :class:`_orm.MapperProperty` objects,
+        which are accessible via the :meth:`_orm.Mapper.get_property`
+        method and the :attr:`_orm.Mapper.iterate_properties` attribute.
+
+        This event differs from the
+        :meth:`_orm.MapperEvents.before_mapper_configured` event in that it
+        is invoked within the constructor for :class:`_orm.Mapper`, rather
+        than within the :meth:`_orm.registry.configure` process.   Currently,
+        this event is the only one which is appropriate for handlers that
+        wish to create additional mapped classes in response to the
+        construction of this :class:`_orm.Mapper`, which will be part of the
+        same configure step when :meth:`_orm.registry.configure` next runs.
+
+        .. versionadded:: 2.0.2
+
+        .. seealso::
+
+            :ref:`examples_versioning` - an example which illustrates the use
+            of the :meth:`_orm.MapperEvents.before_mapper_configured`
+            event to create new mappers to record change-audit histories on
+            objects.
+
+        """
+
+    def before_mapper_configured(
+        self, mapper: Mapper[_O], class_: Type[_O]
+    ) -> None:
+        """Called right before a specific mapper is to be configured.
+
+        This event is intended to allow a specific mapper to be skipped during
+        the configure step, by returning the :attr:`.orm.interfaces.EXT_SKIP`
+        symbol which indicates to the :func:`.configure_mappers` call that this
+        particular mapper (or hierarchy of mappers, if ``propagate=True`` is
+        used) should be skipped in the current configuration run. When one or
+        more mappers are skipped, the "new mappers" flag will remain set,
+        meaning the :func:`.configure_mappers` function will continue to be
+        called when mappers are used, to continue to try to configure all
+        available mappers.
+
+        In comparison to the other configure-level events,
+        :meth:`.MapperEvents.before_configured`,
+        :meth:`.MapperEvents.after_configured`, and
+        :meth:`.MapperEvents.mapper_configured`, the
+        :meth:`.MapperEvents.before_mapper_configured` event provides for a
+        meaningful return value when it is registered with the ``retval=True``
+        parameter.
+
+        .. versionadded:: 1.3
+
+        e.g.::
+
+            from sqlalchemy.orm import EXT_SKIP
+
+            Base = declarative_base()
+
+            DontConfigureBase = declarative_base()
+
+
+            @event.listens_for(
+                DontConfigureBase,
+                "before_mapper_configured",
+                retval=True,
+                propagate=True,
+            )
+            def dont_configure(mapper, cls):
+                return EXT_SKIP
+
+        .. seealso::
+
+            :meth:`.MapperEvents.before_configured`
+
+            :meth:`.MapperEvents.after_configured`
+
+            :meth:`.MapperEvents.mapper_configured`
+
+        """
+
+    def mapper_configured(self, mapper: Mapper[_O], class_: Type[_O]) -> None:
+        r"""Called when a specific mapper has completed its own configuration
+        within the scope of the :func:`.configure_mappers` call.
+
+        The :meth:`.MapperEvents.mapper_configured` event is invoked
+        for each mapper that is encountered when the
+        :func:`_orm.configure_mappers` function proceeds through the current
+        list of not-yet-configured mappers.
+        :func:`_orm.configure_mappers` is typically invoked
+        automatically as mappings are first used, as well as each time
+        new mappers have been made available and new mapper use is
+        detected.
+
+        When the event is called, the mapper should be in its final
+        state, but **not including backrefs** that may be invoked from
+        other mappers; they might still be pending within the
+        configuration operation.    Bidirectional relationships that
+        are instead configured via the
+        :paramref:`.orm.relationship.back_populates` argument
+        *will* be fully available, since this style of relationship does not
+        rely upon other possibly-not-configured mappers to know that they
+        exist.
+
+        For an event that is guaranteed to have **all** mappers ready
+        to go including backrefs that are defined only on other
+        mappings, use the :meth:`.MapperEvents.after_configured`
+        event; this event invokes only after all known mappings have been
+        fully configured.
+
+        The :meth:`.MapperEvents.mapper_configured` event, unlike
+        :meth:`.MapperEvents.before_configured` or
+        :meth:`.MapperEvents.after_configured`,
+        is called for each mapper/class individually, and the mapper is
+        passed to the event itself.  It also is called exactly once for
+        a particular mapper.  The event is therefore useful for
+        configurational steps that benefit from being invoked just once
+        on a specific mapper basis, which don't require that "backref"
+        configurations are necessarily ready yet.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param class\_: the mapped class.
+
+        .. seealso::
+
+            :meth:`.MapperEvents.before_configured`
+
+            :meth:`.MapperEvents.after_configured`
+
+            :meth:`.MapperEvents.before_mapper_configured`
+
+        """
+        # TODO: need coverage for this event
+
+    def before_configured(self) -> None:
+        """Called before a series of mappers have been configured.
+
+        The :meth:`.MapperEvents.before_configured` event is invoked
+        each time the :func:`_orm.configure_mappers` function is
+        invoked, before the function has done any of its work.
+        :func:`_orm.configure_mappers` is typically invoked
+        automatically as mappings are first used, as well as each time
+        new mappers have been made available and new mapper use is
+        detected.
+
+        This event can **only** be applied to the :class:`_orm.Mapper` class,
+        and not to individual mappings or mapped classes. It is only invoked
+        for all mappings as a whole::
+
+            from sqlalchemy.orm import Mapper
+
+
+            @event.listens_for(Mapper, "before_configured")
+            def go(): ...
+
+        Contrast this event to :meth:`.MapperEvents.after_configured`,
+        which is invoked after the series of mappers has been configured,
+        as well as :meth:`.MapperEvents.before_mapper_configured`
+        and :meth:`.MapperEvents.mapper_configured`, which are both invoked
+        on a per-mapper basis.
+
+        Theoretically this event is called once per
+        application, but is actually called any time new mappers
+        are to be affected by a :func:`_orm.configure_mappers`
+        call.   If new mappings are constructed after existing ones have
+        already been used, this event will likely be called again.  To ensure
+        that a particular event is only called once and no further, the
+        ``once=True`` argument (new in 0.9.4) can be applied::
+
+            from sqlalchemy.orm import mapper
+
+
+            @event.listens_for(mapper, "before_configured", once=True)
+            def go(): ...
+
+        .. seealso::
+
+            :meth:`.MapperEvents.before_mapper_configured`
+
+            :meth:`.MapperEvents.mapper_configured`
+
+            :meth:`.MapperEvents.after_configured`
+
+        """
+
+    def after_configured(self) -> None:
+        """Called after a series of mappers have been configured.
+
+        The :meth:`.MapperEvents.after_configured` event is invoked
+        each time the :func:`_orm.configure_mappers` function is
+        invoked, after the function has completed its work.
+        :func:`_orm.configure_mappers` is typically invoked
+        automatically as mappings are first used, as well as each time
+        new mappers have been made available and new mapper use is
+        detected.
+
+        Contrast this event to the :meth:`.MapperEvents.mapper_configured`
+        event, which is called on a per-mapper basis while the configuration
+        operation proceeds; unlike that event, when this event is invoked,
+        all cross-configurations (e.g. backrefs) will also have been made
+        available for any mappers that were pending.
+        Also contrast to :meth:`.MapperEvents.before_configured`,
+        which is invoked before the series of mappers has been configured.
+
+        This event can **only** be applied to the :class:`_orm.Mapper` class,
+        and not to individual mappings or
+        mapped classes.  It is only invoked for all mappings as a whole::
+
+            from sqlalchemy.orm import Mapper
+
+
+            @event.listens_for(Mapper, "after_configured")
+            def go(): ...
+
+        Theoretically this event is called once per
+        application, but is actually called any time new mappers
+        have been affected by a :func:`_orm.configure_mappers`
+        call.   If new mappings are constructed after existing ones have
+        already been used, this event will likely be called again.  To ensure
+        that a particular event is only called once and no further, the
+        ``once=True`` argument (new in 0.9.4) can be applied::
+
+            from sqlalchemy.orm import mapper
+
+
+            @event.listens_for(mapper, "after_configured", once=True)
+            def go(): ...
+
+        .. seealso::
+
+            :meth:`.MapperEvents.before_mapper_configured`
+
+            :meth:`.MapperEvents.mapper_configured`
+
+            :meth:`.MapperEvents.before_configured`
+
+        """
+
+    def before_insert(
+        self, mapper: Mapper[_O], connection: Connection, target: _O
+    ) -> None:
+        """Receive an object instance before an INSERT statement
+        is emitted corresponding to that instance.
+
+        .. note:: this event **only** applies to the
+           :ref:`session flush operation <session_flushing>`
+           and does **not** apply to the ORM DML operations described at
+           :ref:`orm_expression_update_delete`.  To intercept ORM
+           DML events, use :meth:`_orm.SessionEvents.do_orm_execute`.
+
+        This event is used to modify local, non-object related
+        attributes on the instance before an INSERT occurs, as well
+        as to emit additional SQL statements on the given
+        connection.
+
+        The event is often called for a batch of objects of the
+        same class before their INSERT statements are emitted at
+        once in a later step. In the extremely rare case that
+        this is not desirable, the :class:`_orm.Mapper` object can be
+        configured with ``batch=False``, which will cause
+        batches of instances to be broken up into individual
+        (and more poorly performing) event->persist->event
+        steps.
+
+        .. warning::
+
+            Mapper-level flush events only allow **very limited operations**,
+            on attributes local to the row being operated upon only,
+            as well as allowing any SQL to be emitted on the given
+            :class:`_engine.Connection`.  **Please read fully** the notes
+            at :ref:`session_persistence_mapper` for guidelines on using
+            these methods; generally, the :meth:`.SessionEvents.before_flush`
+            method should be preferred for general on-flush changes.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param connection: the :class:`_engine.Connection` being used to
+         emit INSERT statements for this instance.  This
+         provides a handle into the current transaction on the
+         target database specific to this instance.
+        :param target: the mapped instance being persisted.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :return: No return value is supported by this event.
+
+        .. seealso::
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def after_insert(
+        self, mapper: Mapper[_O], connection: Connection, target: _O
+    ) -> None:
+        """Receive an object instance after an INSERT statement
+        is emitted corresponding to that instance.
+
+        .. note:: this event **only** applies to the
+           :ref:`session flush operation <session_flushing>`
+           and does **not** apply to the ORM DML operations described at
+           :ref:`orm_expression_update_delete`.  To intercept ORM
+           DML events, use :meth:`_orm.SessionEvents.do_orm_execute`.
+
+        This event is used to modify in-Python-only
+        state on the instance after an INSERT occurs, as well
+        as to emit additional SQL statements on the given
+        connection.
+
+        The event is often called for a batch of objects of the
+        same class after their INSERT statements have been
+        emitted at once in a previous step. In the extremely
+        rare case that this is not desirable, the
+        :class:`_orm.Mapper` object can be configured with ``batch=False``,
+        which will cause batches of instances to be broken up
+        into individual (and more poorly performing)
+        event->persist->event steps.
+
+        .. warning::
+
+            Mapper-level flush events only allow **very limited operations**,
+            on attributes local to the row being operated upon only,
+            as well as allowing any SQL to be emitted on the given
+            :class:`_engine.Connection`.  **Please read fully** the notes
+            at :ref:`session_persistence_mapper` for guidelines on using
+            these methods; generally, the :meth:`.SessionEvents.before_flush`
+            method should be preferred for general on-flush changes.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param connection: the :class:`_engine.Connection` being used to
+         emit INSERT statements for this instance.  This
+         provides a handle into the current transaction on the
+         target database specific to this instance.
+        :param target: the mapped instance being persisted.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :return: No return value is supported by this event.
+
+        .. seealso::
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def before_update(
+        self, mapper: Mapper[_O], connection: Connection, target: _O
+    ) -> None:
+        """Receive an object instance before an UPDATE statement
+        is emitted corresponding to that instance.
+
+        .. note:: this event **only** applies to the
+           :ref:`session flush operation <session_flushing>`
+           and does **not** apply to the ORM DML operations described at
+           :ref:`orm_expression_update_delete`.  To intercept ORM
+           DML events, use :meth:`_orm.SessionEvents.do_orm_execute`.
+
+        This event is used to modify local, non-object related
+        attributes on the instance before an UPDATE occurs, as well
+        as to emit additional SQL statements on the given
+        connection.
+
+        This method is called for all instances that are
+        marked as "dirty", *even those which have no net changes
+        to their column-based attributes*. An object is marked
+        as dirty when any of its column-based attributes have a
+        "set attribute" operation called or when any of its
+        collections are modified. If, at update time, no
+        column-based attributes have any net changes, no UPDATE
+        statement will be issued. This means that an instance
+        being sent to :meth:`~.MapperEvents.before_update` is
+        *not* a guarantee that an UPDATE statement will be
+        issued, although you can affect the outcome here by
+        modifying attributes so that a net change in value does
+        exist.
+
+        To detect if the column-based attributes on the object have net
+        changes, and will therefore generate an UPDATE statement, use
+        ``object_session(instance).is_modified(instance,
+        include_collections=False)``.
+
+        The event is often called for a batch of objects of the
+        same class before their UPDATE statements are emitted at
+        once in a later step. In the extremely rare case that
+        this is not desirable, the :class:`_orm.Mapper` can be
+        configured with ``batch=False``, which will cause
+        batches of instances to be broken up into individual
+        (and more poorly performing) event->persist->event
+        steps.
+
+        .. warning::
+
+            Mapper-level flush events only allow **very limited operations**,
+            on attributes local to the row being operated upon only,
+            as well as allowing any SQL to be emitted on the given
+            :class:`_engine.Connection`.  **Please read fully** the notes
+            at :ref:`session_persistence_mapper` for guidelines on using
+            these methods; generally, the :meth:`.SessionEvents.before_flush`
+            method should be preferred for general on-flush changes.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param connection: the :class:`_engine.Connection` being used to
+         emit UPDATE statements for this instance.  This
+         provides a handle into the current transaction on the
+         target database specific to this instance.
+        :param target: the mapped instance being persisted.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :return: No return value is supported by this event.
+
+        .. seealso::
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def after_update(
+        self, mapper: Mapper[_O], connection: Connection, target: _O
+    ) -> None:
+        """Receive an object instance after an UPDATE statement
+        is emitted corresponding to that instance.
+
+        .. note:: this event **only** applies to the
+           :ref:`session flush operation <session_flushing>`
+           and does **not** apply to the ORM DML operations described at
+           :ref:`orm_expression_update_delete`.  To intercept ORM
+           DML events, use :meth:`_orm.SessionEvents.do_orm_execute`.
+
+        This event is used to modify in-Python-only
+        state on the instance after an UPDATE occurs, as well
+        as to emit additional SQL statements on the given
+        connection.
+
+        This method is called for all instances that are
+        marked as "dirty", *even those which have no net changes
+        to their column-based attributes*, and for which
+        no UPDATE statement has proceeded. An object is marked
+        as dirty when any of its column-based attributes have a
+        "set attribute" operation called or when any of its
+        collections are modified. If, at update time, no
+        column-based attributes have any net changes, no UPDATE
+        statement will be issued. This means that an instance
+        being sent to :meth:`~.MapperEvents.after_update` is
+        *not* a guarantee that an UPDATE statement has been
+        issued.
+
+        To detect if the column-based attributes on the object have net
+        changes, and therefore resulted in an UPDATE statement, use
+        ``object_session(instance).is_modified(instance,
+        include_collections=False)``.
+
+        The event is often called for a batch of objects of the
+        same class after their UPDATE statements have been emitted at
+        once in a previous step. In the extremely rare case that
+        this is not desirable, the :class:`_orm.Mapper` can be
+        configured with ``batch=False``, which will cause
+        batches of instances to be broken up into individual
+        (and more poorly performing) event->persist->event
+        steps.
+
+        .. warning::
+
+            Mapper-level flush events only allow **very limited operations**,
+            on attributes local to the row being operated upon only,
+            as well as allowing any SQL to be emitted on the given
+            :class:`_engine.Connection`.  **Please read fully** the notes
+            at :ref:`session_persistence_mapper` for guidelines on using
+            these methods; generally, the :meth:`.SessionEvents.before_flush`
+            method should be preferred for general on-flush changes.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param connection: the :class:`_engine.Connection` being used to
+         emit UPDATE statements for this instance.  This
+         provides a handle into the current transaction on the
+         target database specific to this instance.
+        :param target: the mapped instance being persisted.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :return: No return value is supported by this event.
+
+        .. seealso::
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def before_delete(
+        self, mapper: Mapper[_O], connection: Connection, target: _O
+    ) -> None:
+        """Receive an object instance before a DELETE statement
+        is emitted corresponding to that instance.
+
+        .. note:: this event **only** applies to the
+           :ref:`session flush operation <session_flushing>`
+           and does **not** apply to the ORM DML operations described at
+           :ref:`orm_expression_update_delete`.  To intercept ORM
+           DML events, use :meth:`_orm.SessionEvents.do_orm_execute`.
+
+        This event is used to emit additional SQL statements on
+        the given connection as well as to perform application
+        specific bookkeeping related to a deletion event.
+
+        The event is often called for a batch of objects of the
+        same class before their DELETE statements are emitted at
+        once in a later step.
+
+        .. warning::
+
+            Mapper-level flush events only allow **very limited operations**,
+            on attributes local to the row being operated upon only,
+            as well as allowing any SQL to be emitted on the given
+            :class:`_engine.Connection`.  **Please read fully** the notes
+            at :ref:`session_persistence_mapper` for guidelines on using
+            these methods; generally, the :meth:`.SessionEvents.before_flush`
+            method should be preferred for general on-flush changes.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param connection: the :class:`_engine.Connection` being used to
+         emit DELETE statements for this instance.  This
+         provides a handle into the current transaction on the
+         target database specific to this instance.
+        :param target: the mapped instance being deleted.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :return: No return value is supported by this event.
+
+        .. seealso::
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def after_delete(
+        self, mapper: Mapper[_O], connection: Connection, target: _O
+    ) -> None:
+        """Receive an object instance after a DELETE statement
+        has been emitted corresponding to that instance.
+
+        .. note:: this event **only** applies to the
+           :ref:`session flush operation <session_flushing>`
+           and does **not** apply to the ORM DML operations described at
+           :ref:`orm_expression_update_delete`.  To intercept ORM
+           DML events, use :meth:`_orm.SessionEvents.do_orm_execute`.
+
+        This event is used to emit additional SQL statements on
+        the given connection as well as to perform application
+        specific bookkeeping related to a deletion event.
+
+        The event is often called for a batch of objects of the
+        same class after their DELETE statements have been emitted at
+        once in a previous step.
+
+        .. warning::
+
+            Mapper-level flush events only allow **very limited operations**,
+            on attributes local to the row being operated upon only,
+            as well as allowing any SQL to be emitted on the given
+            :class:`_engine.Connection`.  **Please read fully** the notes
+            at :ref:`session_persistence_mapper` for guidelines on using
+            these methods; generally, the :meth:`.SessionEvents.before_flush`
+            method should be preferred for general on-flush changes.
+
+        :param mapper: the :class:`_orm.Mapper` which is the target
+         of this event.
+        :param connection: the :class:`_engine.Connection` being used to
+         emit DELETE statements for this instance.  This
+         provides a handle into the current transaction on the
+         target database specific to this instance.
+        :param target: the mapped instance being deleted.  If
+         the event is configured with ``raw=True``, this will
+         instead be the :class:`.InstanceState` state-management
+         object associated with the instance.
+        :return: No return value is supported by this event.
+
+        .. seealso::
+
+            :ref:`session_persistence_events`
+
+        """
+
+
+class _MapperEventsHold(_EventsHold[_ET]):
+    all_holds = weakref.WeakKeyDictionary()
+
+    def resolve(
+        self, class_: Union[Type[_T], _InternalEntityType[_T]]
+    ) -> Optional[Mapper[_T]]:
+        return _mapper_or_none(class_)
+
+    class HoldMapperEvents(_EventsHold.HoldEvents[_ET], MapperEvents):  # type: ignore [misc] # noqa: E501
+        pass
+
+    dispatch = event.dispatcher(HoldMapperEvents)
+
+
+_sessionevents_lifecycle_event_names: Set[str] = set()
+
+
+class SessionEvents(event.Events[Session]):
+    """Define events specific to :class:`.Session` lifecycle.
+
+    e.g.::
+
+        from sqlalchemy import event
+        from sqlalchemy.orm import sessionmaker
+
+
+        def my_before_commit(session):
+            print("before commit!")
+
+
+        Session = sessionmaker()
+
+        event.listen(Session, "before_commit", my_before_commit)
+
+    The :func:`~.event.listen` function will accept
+    :class:`.Session` objects as well as the return result
+    of :class:`~.sessionmaker()` and :class:`~.scoped_session()`.
+
+    Additionally, it accepts the :class:`.Session` class which
+    will apply listeners to all :class:`.Session` instances
+    globally.
+
+    :param raw=False: When True, the "target" argument passed
+       to applicable event listener functions that work on individual
+       objects will be the instance's :class:`.InstanceState` management
+       object, rather than the mapped instance itself.
+
+       .. versionadded:: 1.3.14
+
+    :param restore_load_context=False: Applies to the
+       :meth:`.SessionEvents.loaded_as_persistent` event.  Restores the loader
+       context of the object when the event hook is complete, so that ongoing
+       eager load operations continue to target the object appropriately.  A
+       warning is emitted if the object is moved to a new loader context from
+       within this event if this flag is not set.
+
+       .. versionadded:: 1.3.14
+
+    """
+
+    _target_class_doc = "SomeSessionClassOrObject"
+
+    _dispatch_target = Session
+
+    def _lifecycle_event(  # type: ignore [misc]
+        fn: Callable[[SessionEvents, Session, Any], None]
+    ) -> Callable[[SessionEvents, Session, Any], None]:
+        _sessionevents_lifecycle_event_names.add(fn.__name__)
+        return fn
+
+    @classmethod
+    def _accept_with(  # type: ignore [return]
+        cls, target: Any, identifier: str
+    ) -> Union[Session, type]:
+        if isinstance(target, scoped_session):
+            target = target.session_factory
+            if not isinstance(target, sessionmaker) and (
+                not isinstance(target, type) or not issubclass(target, Session)
+            ):
+                raise exc.ArgumentError(
+                    "Session event listen on a scoped_session "
+                    "requires that its creation callable "
+                    "is associated with the Session class."
+                )
+
+        if isinstance(target, sessionmaker):
+            return target.class_
+        elif isinstance(target, type):
+            if issubclass(target, scoped_session):
+                return Session
+            elif issubclass(target, Session):
+                return target
+        elif isinstance(target, Session):
+            return target
+        elif hasattr(target, "_no_async_engine_events"):
+            target._no_async_engine_events()
+        else:
+            # allows alternate SessionEvents-like-classes to be consulted
+            return event.Events._accept_with(target, identifier)  # type: ignore [return-value] # noqa: E501
+
+    @classmethod
+    def _listen(
+        cls,
+        event_key: Any,
+        *,
+        raw: bool = False,
+        restore_load_context: bool = False,
+        **kw: Any,
+    ) -> None:
+        is_instance_event = (
+            event_key.identifier in _sessionevents_lifecycle_event_names
+        )
+
+        if is_instance_event:
+            if not raw or restore_load_context:
+                fn = event_key._listen_fn
+
+                def wrap(
+                    session: Session,
+                    state: InstanceState[_O],
+                    *arg: Any,
+                    **kw: Any,
+                ) -> Optional[Any]:
+                    if not raw:
+                        target = state.obj()
+                        if target is None:
+                            # existing behavior is that if the object is
+                            # garbage collected, no event is emitted
+                            return None
+                    else:
+                        target = state  # type: ignore [assignment]
+                    if restore_load_context:
+                        runid = state.runid
+                    try:
+                        return fn(session, target, *arg, **kw)
+                    finally:
+                        if restore_load_context:
+                            state.runid = runid
+
+                event_key = event_key.with_wrapper(wrap)
+
+        event_key.base_listen(**kw)
+
+    def do_orm_execute(self, orm_execute_state: ORMExecuteState) -> None:
+        """Intercept statement executions that occur on behalf of an
+        ORM :class:`.Session` object.
+
+        This event is invoked for all top-level SQL statements invoked from the
+        :meth:`_orm.Session.execute` method, as well as related methods such as
+        :meth:`_orm.Session.scalars` and :meth:`_orm.Session.scalar`. As of
+        SQLAlchemy 1.4, all ORM queries that run through the
+        :meth:`_orm.Session.execute` method as well as related methods
+        :meth:`_orm.Session.scalars`, :meth:`_orm.Session.scalar` etc.
+        will participate in this event.
+        This event hook does **not** apply to the queries that are
+        emitted internally within the ORM flush process, i.e. the
+        process described at :ref:`session_flushing`.
+
+        .. note::  The :meth:`_orm.SessionEvents.do_orm_execute` event hook
+           is triggered **for ORM statement executions only**, meaning those
+           invoked via the :meth:`_orm.Session.execute` and similar methods on
+           the :class:`_orm.Session` object. It does **not** trigger for
+           statements that are invoked by SQLAlchemy Core only, i.e. statements
+           invoked directly using :meth:`_engine.Connection.execute` or
+           otherwise originating from an :class:`_engine.Engine` object without
+           any :class:`_orm.Session` involved. To intercept **all** SQL
+           executions regardless of whether the Core or ORM APIs are in use,
+           see the event hooks at :class:`.ConnectionEvents`, such as
+           :meth:`.ConnectionEvents.before_execute` and
+           :meth:`.ConnectionEvents.before_cursor_execute`.
+
+           Also, this event hook does **not** apply to queries that are
+           emitted internally within the ORM flush process,
+           i.e. the process described at :ref:`session_flushing`; to
+           intercept steps within the flush process, see the event
+           hooks described at :ref:`session_persistence_events` as
+           well as :ref:`session_persistence_mapper`.
+
+        This event is a ``do_`` event, meaning it has the capability to replace
+        the operation that the :meth:`_orm.Session.execute` method normally
+        performs.  The intended use for this includes sharding and
+        result-caching schemes which may seek to invoke the same statement
+        across  multiple database connections, returning a result that is
+        merged from each of them, or which don't invoke the statement at all,
+        instead returning data from a cache.
+
+        The hook intends to replace the use of the
+        ``Query._execute_and_instances`` method that could be subclassed prior
+        to SQLAlchemy 1.4.
+
+        :param orm_execute_state: an instance of :class:`.ORMExecuteState`
+         which contains all information about the current execution, as well
+         as helper functions used to derive other commonly required
+         information.   See that object for details.
+
+        .. seealso::
+
+            :ref:`session_execute_events` - top level documentation on how
+            to use :meth:`_orm.SessionEvents.do_orm_execute`
+
+            :class:`.ORMExecuteState` - the object passed to the
+            :meth:`_orm.SessionEvents.do_orm_execute` event which contains
+            all information about the statement to be invoked.  It also
+            provides an interface to extend the current statement, options,
+            and parameters as well as an option that allows programmatic
+            invocation of the statement at any point.
+
+            :ref:`examples_session_orm_events` - includes examples of using
+            :meth:`_orm.SessionEvents.do_orm_execute`
+
+            :ref:`examples_caching` - an example of how to integrate
+            Dogpile caching with the ORM :class:`_orm.Session` making use
+            of the :meth:`_orm.SessionEvents.do_orm_execute` event hook.
+
+            :ref:`examples_sharding` - the Horizontal Sharding example /
+            extension relies upon the
+            :meth:`_orm.SessionEvents.do_orm_execute` event hook to invoke a
+            SQL statement on multiple backends and return a merged result.
+
+
+        .. versionadded:: 1.4
+
+        """
+
+    def after_transaction_create(
+        self, session: Session, transaction: SessionTransaction
+    ) -> None:
+        """Execute when a new :class:`.SessionTransaction` is created.
+
+        This event differs from :meth:`~.SessionEvents.after_begin`
+        in that it occurs for each :class:`.SessionTransaction`
+        overall, as opposed to when transactions are begun
+        on individual database connections.  It is also invoked
+        for nested transactions and subtransactions, and is always
+        matched by a corresponding
+        :meth:`~.SessionEvents.after_transaction_end` event
+        (assuming normal operation of the :class:`.Session`).
+
+        :param session: the target :class:`.Session`.
+        :param transaction: the target :class:`.SessionTransaction`.
+
+         To detect if this is the outermost
+         :class:`.SessionTransaction`, as opposed to a "subtransaction" or a
+         SAVEPOINT, test that the :attr:`.SessionTransaction.parent` attribute
+         is ``None``::
+
+                @event.listens_for(session, "after_transaction_create")
+                def after_transaction_create(session, transaction):
+                    if transaction.parent is None:
+                        ...  # work with top-level transaction
+
+         To detect if the :class:`.SessionTransaction` is a SAVEPOINT, use the
+         :attr:`.SessionTransaction.nested` attribute::
+
+                @event.listens_for(session, "after_transaction_create")
+                def after_transaction_create(session, transaction):
+                    if transaction.nested:
+                        ...  # work with SAVEPOINT transaction
+
+        .. seealso::
+
+            :class:`.SessionTransaction`
+
+            :meth:`~.SessionEvents.after_transaction_end`
+
+        """
+
+    def after_transaction_end(
+        self, session: Session, transaction: SessionTransaction
+    ) -> None:
+        """Execute when the span of a :class:`.SessionTransaction` ends.
+
+        This event differs from :meth:`~.SessionEvents.after_commit`
+        in that it corresponds to all :class:`.SessionTransaction`
+        objects in use, including those for nested transactions
+        and subtransactions, and is always matched by a corresponding
+        :meth:`~.SessionEvents.after_transaction_create` event.
+
+        :param session: the target :class:`.Session`.
+        :param transaction: the target :class:`.SessionTransaction`.
+
+         To detect if this is the outermost
+         :class:`.SessionTransaction`, as opposed to a "subtransaction" or a
+         SAVEPOINT, test that the :attr:`.SessionTransaction.parent` attribute
+         is ``None``::
+
+                @event.listens_for(session, "after_transaction_create")
+                def after_transaction_end(session, transaction):
+                    if transaction.parent is None:
+                        ...  # work with top-level transaction
+
+         To detect if the :class:`.SessionTransaction` is a SAVEPOINT, use the
+         :attr:`.SessionTransaction.nested` attribute::
+
+                @event.listens_for(session, "after_transaction_create")
+                def after_transaction_end(session, transaction):
+                    if transaction.nested:
+                        ...  # work with SAVEPOINT transaction
+
+        .. seealso::
+
+            :class:`.SessionTransaction`
+
+            :meth:`~.SessionEvents.after_transaction_create`
+
+        """
+
+    def before_commit(self, session: Session) -> None:
+        """Execute before commit is called.
+
+        .. note::
+
+            The :meth:`~.SessionEvents.before_commit` hook is *not* per-flush,
+            that is, the :class:`.Session` can emit SQL to the database
+            many times within the scope of a transaction.
+            For interception of these events, use the
+            :meth:`~.SessionEvents.before_flush`,
+            :meth:`~.SessionEvents.after_flush`, or
+            :meth:`~.SessionEvents.after_flush_postexec`
+            events.
+
+        :param session: The target :class:`.Session`.
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.after_commit`
+
+            :meth:`~.SessionEvents.after_begin`
+
+            :meth:`~.SessionEvents.after_transaction_create`
+
+            :meth:`~.SessionEvents.after_transaction_end`
+
+        """
+
+    def after_commit(self, session: Session) -> None:
+        """Execute after a commit has occurred.
+
+        .. note::
+
+            The :meth:`~.SessionEvents.after_commit` hook is *not* per-flush,
+            that is, the :class:`.Session` can emit SQL to the database
+            many times within the scope of a transaction.
+            For interception of these events, use the
+            :meth:`~.SessionEvents.before_flush`,
+            :meth:`~.SessionEvents.after_flush`, or
+            :meth:`~.SessionEvents.after_flush_postexec`
+            events.
+
+        .. note::
+
+            The :class:`.Session` is not in an active transaction
+            when the :meth:`~.SessionEvents.after_commit` event is invoked,
+            and therefore can not emit SQL.  To emit SQL corresponding to
+            every transaction, use the :meth:`~.SessionEvents.before_commit`
+            event.
+
+        :param session: The target :class:`.Session`.
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.before_commit`
+
+            :meth:`~.SessionEvents.after_begin`
+
+            :meth:`~.SessionEvents.after_transaction_create`
+
+            :meth:`~.SessionEvents.after_transaction_end`
+
+        """
+
+    def after_rollback(self, session: Session) -> None:
+        """Execute after a real DBAPI rollback has occurred.
+
+        Note that this event only fires when the *actual* rollback against
+        the database occurs - it does *not* fire each time the
+        :meth:`.Session.rollback` method is called, if the underlying
+        DBAPI transaction has already been rolled back.  In many
+        cases, the :class:`.Session` will not be in
+        an "active" state during this event, as the current
+        transaction is not valid.   To acquire a :class:`.Session`
+        which is active after the outermost rollback has proceeded,
+        use the :meth:`.SessionEvents.after_soft_rollback` event, checking the
+        :attr:`.Session.is_active` flag.
+
+        :param session: The target :class:`.Session`.
+
+        """
+
+    def after_soft_rollback(
+        self, session: Session, previous_transaction: SessionTransaction
+    ) -> None:
+        """Execute after any rollback has occurred, including "soft"
+        rollbacks that don't actually emit at the DBAPI level.
+
+        This corresponds to both nested and outer rollbacks, i.e.
+        the innermost rollback that calls the DBAPI's
+        rollback() method, as well as the enclosing rollback
+        calls that only pop themselves from the transaction stack.
+
+        The given :class:`.Session` can be used to invoke SQL and
+        :meth:`.Session.query` operations after an outermost rollback
+        by first checking the :attr:`.Session.is_active` flag::
+
+            @event.listens_for(Session, "after_soft_rollback")
+            def do_something(session, previous_transaction):
+                if session.is_active:
+                    session.execute(text("select * from some_table"))
+
+        :param session: The target :class:`.Session`.
+        :param previous_transaction: The :class:`.SessionTransaction`
+         transactional marker object which was just closed.   The current
+         :class:`.SessionTransaction` for the given :class:`.Session` is
+         available via the :attr:`.Session.transaction` attribute.
+
+        """
+
+    def before_flush(
+        self,
+        session: Session,
+        flush_context: UOWTransaction,
+        instances: Optional[Sequence[_O]],
+    ) -> None:
+        """Execute before flush process has started.
+
+        :param session: The target :class:`.Session`.
+        :param flush_context: Internal :class:`.UOWTransaction` object
+         which handles the details of the flush.
+        :param instances: Usually ``None``, this is the collection of
+         objects which can be passed to the :meth:`.Session.flush` method
+         (note this usage is deprecated).
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.after_flush`
+
+            :meth:`~.SessionEvents.after_flush_postexec`
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def after_flush(
+        self, session: Session, flush_context: UOWTransaction
+    ) -> None:
+        """Execute after flush has completed, but before commit has been
+        called.
+
+        Note that the session's state is still in pre-flush, i.e. 'new',
+        'dirty', and 'deleted' lists still show pre-flush state as well
+        as the history settings on instance attributes.
+
+        .. warning:: This event runs after the :class:`.Session` has emitted
+           SQL to modify the database, but **before** it has altered its
+           internal state to reflect those changes, including that newly
+           inserted objects are placed into the identity map.  ORM operations
+           emitted within this event such as loads of related items
+           may produce new identity map entries that will immediately
+           be replaced, sometimes causing confusing results.  SQLAlchemy will
+           emit a warning for this condition as of version 1.3.9.
+
+        :param session: The target :class:`.Session`.
+        :param flush_context: Internal :class:`.UOWTransaction` object
+         which handles the details of the flush.
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.before_flush`
+
+            :meth:`~.SessionEvents.after_flush_postexec`
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def after_flush_postexec(
+        self, session: Session, flush_context: UOWTransaction
+    ) -> None:
+        """Execute after flush has completed, and after the post-exec
+        state occurs.
+
+        This will be when the 'new', 'dirty', and 'deleted' lists are in
+        their final state.  An actual commit() may or may not have
+        occurred, depending on whether or not the flush started its own
+        transaction or participated in a larger transaction.
+
+        :param session: The target :class:`.Session`.
+        :param flush_context: Internal :class:`.UOWTransaction` object
+         which handles the details of the flush.
+
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.before_flush`
+
+            :meth:`~.SessionEvents.after_flush`
+
+            :ref:`session_persistence_events`
+
+        """
+
+    def after_begin(
+        self,
+        session: Session,
+        transaction: SessionTransaction,
+        connection: Connection,
+    ) -> None:
+        """Execute after a transaction is begun on a connection.
+
+        .. note:: This event is called within the process of the
+          :class:`_orm.Session` modifying its own internal state.
+          To invoke SQL operations within this hook, use the
+          :class:`_engine.Connection` provided to the event;
+          do not run SQL operations using the :class:`_orm.Session`
+          directly.
+
+        :param session: The target :class:`.Session`.
+        :param transaction: The :class:`.SessionTransaction`.
+        :param connection: The :class:`_engine.Connection` object
+         which will be used for SQL statements.
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.before_commit`
+
+            :meth:`~.SessionEvents.after_commit`
+
+            :meth:`~.SessionEvents.after_transaction_create`
+
+            :meth:`~.SessionEvents.after_transaction_end`
+
+        """
+
+    @_lifecycle_event
+    def before_attach(self, session: Session, instance: _O) -> None:
+        """Execute before an instance is attached to a session.
+
+        This is called before an add, delete or merge causes
+        the object to be part of the session.
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.after_attach`
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def after_attach(self, session: Session, instance: _O) -> None:
+        """Execute after an instance is attached to a session.
+
+        This is called after an add, delete or merge.
+
+        .. note::
+
+           As of 0.8, this event fires off *after* the item
+           has been fully associated with the session, which is
+           different than previous releases.  For event
+           handlers that require the object not yet
+           be part of session state (such as handlers which
+           may autoflush while the target object is not
+           yet complete) consider the
+           new :meth:`.before_attach` event.
+
+        .. seealso::
+
+            :meth:`~.SessionEvents.before_attach`
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @event._legacy_signature(
+        "0.9",
+        ["session", "query", "query_context", "result"],
+        lambda update_context: (
+            update_context.session,
+            update_context.query,
+            None,
+            update_context.result,
+        ),
+    )
+    def after_bulk_update(self, update_context: _O) -> None:
+        """Event for after the legacy :meth:`_orm.Query.update` method
+        has been called.
+
+        .. legacy:: The :meth:`_orm.SessionEvents.after_bulk_update` method
+           is a legacy event hook as of SQLAlchemy 2.0.   The event
+           **does not participate** in :term:`2.0 style` invocations
+           using :func:`_dml.update` documented at
+           :ref:`orm_queryguide_update_delete_where`.  For 2.0 style use,
+           the :meth:`_orm.SessionEvents.do_orm_execute` hook will intercept
+           these calls.
+
+        :param update_context: an "update context" object which contains
+         details about the update, including these attributes:
+
+            * ``session`` - the :class:`.Session` involved
+            * ``query`` -the :class:`_query.Query`
+              object that this update operation
+              was called upon.
+            * ``values`` The "values" dictionary that was passed to
+              :meth:`_query.Query.update`.
+            * ``result`` the :class:`_engine.CursorResult`
+              returned as a result of the
+              bulk UPDATE operation.
+
+        .. versionchanged:: 1.4 the update_context no longer has a
+           ``QueryContext`` object associated with it.
+
+        .. seealso::
+
+            :meth:`.QueryEvents.before_compile_update`
+
+            :meth:`.SessionEvents.after_bulk_delete`
+
+        """
+
+    @event._legacy_signature(
+        "0.9",
+        ["session", "query", "query_context", "result"],
+        lambda delete_context: (
+            delete_context.session,
+            delete_context.query,
+            None,
+            delete_context.result,
+        ),
+    )
+    def after_bulk_delete(self, delete_context: _O) -> None:
+        """Event for after the legacy :meth:`_orm.Query.delete` method
+        has been called.
+
+        .. legacy:: The :meth:`_orm.SessionEvents.after_bulk_delete` method
+           is a legacy event hook as of SQLAlchemy 2.0.   The event
+           **does not participate** in :term:`2.0 style` invocations
+           using :func:`_dml.delete` documented at
+           :ref:`orm_queryguide_update_delete_where`.  For 2.0 style use,
+           the :meth:`_orm.SessionEvents.do_orm_execute` hook will intercept
+           these calls.
+
+        :param delete_context: a "delete context" object which contains
+         details about the update, including these attributes:
+
+            * ``session`` - the :class:`.Session` involved
+            * ``query`` -the :class:`_query.Query`
+              object that this update operation
+              was called upon.
+            * ``result`` the :class:`_engine.CursorResult`
+              returned as a result of the
+              bulk DELETE operation.
+
+        .. versionchanged:: 1.4 the update_context no longer has a
+           ``QueryContext`` object associated with it.
+
+        .. seealso::
+
+            :meth:`.QueryEvents.before_compile_delete`
+
+            :meth:`.SessionEvents.after_bulk_update`
+
+        """
+
+    @_lifecycle_event
+    def transient_to_pending(self, session: Session, instance: _O) -> None:
+        """Intercept the "transient to pending" transition for a specific
+        object.
+
+        This event is a specialization of the
+        :meth:`.SessionEvents.after_attach` event which is only invoked
+        for this specific transition.  It is invoked typically during the
+        :meth:`.Session.add` call.
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def pending_to_transient(self, session: Session, instance: _O) -> None:
+        """Intercept the "pending to transient" transition for a specific
+        object.
+
+        This less common transition occurs when an pending object that has
+        not been flushed is evicted from the session; this can occur
+        when the :meth:`.Session.rollback` method rolls back the transaction,
+        or when the :meth:`.Session.expunge` method is used.
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def persistent_to_transient(self, session: Session, instance: _O) -> None:
+        """Intercept the "persistent to transient" transition for a specific
+        object.
+
+        This less common transition occurs when an pending object that has
+        has been flushed is evicted from the session; this can occur
+        when the :meth:`.Session.rollback` method rolls back the transaction.
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def pending_to_persistent(self, session: Session, instance: _O) -> None:
+        """Intercept the "pending to persistent"" transition for a specific
+        object.
+
+        This event is invoked within the flush process, and is
+        similar to scanning the :attr:`.Session.new` collection within
+        the :meth:`.SessionEvents.after_flush` event.  However, in this
+        case the object has already been moved to the persistent state
+        when the event is called.
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def detached_to_persistent(self, session: Session, instance: _O) -> None:
+        """Intercept the "detached to persistent" transition for a specific
+        object.
+
+        This event is a specialization of the
+        :meth:`.SessionEvents.after_attach` event which is only invoked
+        for this specific transition.  It is invoked typically during the
+        :meth:`.Session.add` call, as well as during the
+        :meth:`.Session.delete` call if the object was not previously
+        associated with the
+        :class:`.Session` (note that an object marked as "deleted" remains
+        in the "persistent" state until the flush proceeds).
+
+        .. note::
+
+            If the object becomes persistent as part of a call to
+            :meth:`.Session.delete`, the object is **not** yet marked as
+            deleted when this event is called.  To detect deleted objects,
+            check the ``deleted`` flag sent to the
+            :meth:`.SessionEvents.persistent_to_detached` to event after the
+            flush proceeds, or check the :attr:`.Session.deleted` collection
+            within the :meth:`.SessionEvents.before_flush` event if deleted
+            objects need to be intercepted before the flush.
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def loaded_as_persistent(self, session: Session, instance: _O) -> None:
+        """Intercept the "loaded as persistent" transition for a specific
+        object.
+
+        This event is invoked within the ORM loading process, and is invoked
+        very similarly to the :meth:`.InstanceEvents.load` event.  However,
+        the event here is linkable to a :class:`.Session` class or instance,
+        rather than to a mapper or class hierarchy, and integrates
+        with the other session lifecycle events smoothly.  The object
+        is guaranteed to be present in the session's identity map when
+        this event is called.
+
+        .. note:: This event is invoked within the loader process before
+           eager loaders may have been completed, and the object's state may
+           not be complete.  Additionally, invoking row-level refresh
+           operations on the object will place the object into a new loader
+           context, interfering with the existing load context.   See the note
+           on :meth:`.InstanceEvents.load` for background on making use of the
+           :paramref:`.SessionEvents.restore_load_context` parameter, which
+           works in the same manner as that of
+           :paramref:`.InstanceEvents.restore_load_context`, in  order to
+           resolve this scenario.
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def persistent_to_deleted(self, session: Session, instance: _O) -> None:
+        """Intercept the "persistent to deleted" transition for a specific
+        object.
+
+        This event is invoked when a persistent object's identity
+        is deleted from the database within a flush, however the object
+        still remains associated with the :class:`.Session` until the
+        transaction completes.
+
+        If the transaction is rolled back, the object moves again
+        to the persistent state, and the
+        :meth:`.SessionEvents.deleted_to_persistent` event is called.
+        If the transaction is committed, the object becomes detached,
+        which will emit the :meth:`.SessionEvents.deleted_to_detached`
+        event.
+
+        Note that while the :meth:`.Session.delete` method is the primary
+        public interface to mark an object as deleted, many objects
+        get deleted due to cascade rules, which are not always determined
+        until flush time.  Therefore, there's no way to catch
+        every object that will be deleted until the flush has proceeded.
+        the :meth:`.SessionEvents.persistent_to_deleted` event is therefore
+        invoked at the end of a flush.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def deleted_to_persistent(self, session: Session, instance: _O) -> None:
+        """Intercept the "deleted to persistent" transition for a specific
+        object.
+
+        This transition occurs only when an object that's been deleted
+        successfully in a flush is restored due to a call to
+        :meth:`.Session.rollback`.   The event is not called under
+        any other circumstances.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def deleted_to_detached(self, session: Session, instance: _O) -> None:
+        """Intercept the "deleted to detached" transition for a specific
+        object.
+
+        This event is invoked when a deleted object is evicted
+        from the session.   The typical case when this occurs is when
+        the transaction for a :class:`.Session` in which the object
+        was deleted is committed; the object moves from the deleted
+        state to the detached state.
+
+        It is also invoked for objects that were deleted in a flush
+        when the :meth:`.Session.expunge_all` or :meth:`.Session.close`
+        events are called, as well as if the object is individually
+        expunged from its deleted state via :meth:`.Session.expunge`.
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+    @_lifecycle_event
+    def persistent_to_detached(self, session: Session, instance: _O) -> None:
+        """Intercept the "persistent to detached" transition for a specific
+        object.
+
+        This event is invoked when a persistent object is evicted
+        from the session.  There are many conditions that cause this
+        to happen, including:
+
+        * using a method such as :meth:`.Session.expunge`
+          or :meth:`.Session.close`
+
+        * Calling the :meth:`.Session.rollback` method, when the object
+          was part of an INSERT statement for that session's transaction
+
+
+        :param session: target :class:`.Session`
+
+        :param instance: the ORM-mapped instance being operated upon.
+
+        :param deleted: boolean.  If True, indicates this object moved
+         to the detached state because it was marked as deleted and flushed.
+
+
+        .. seealso::
+
+            :ref:`session_lifecycle_events`
+
+        """
+
+
+class AttributeEvents(event.Events[QueryableAttribute[Any]]):
+    r"""Define events for object attributes.
+
+    These are typically defined on the class-bound descriptor for the
+    target class.
+
+    For example, to register a listener that will receive the
+    :meth:`_orm.AttributeEvents.append` event::
+
+        from sqlalchemy import event
+
+
+        @event.listens_for(MyClass.collection, "append", propagate=True)
+        def my_append_listener(target, value, initiator):
+            print("received append event for target: %s" % target)
+
+    Listeners have the option to return a possibly modified version of the
+    value, when the :paramref:`.AttributeEvents.retval` flag is passed to
+    :func:`.event.listen` or :func:`.event.listens_for`, such as below,
+    illustrated using the :meth:`_orm.AttributeEvents.set` event::
+
+        def validate_phone(target, value, oldvalue, initiator):
+            "Strip non-numeric characters from a phone number"
+
+            return re.sub(r"\D", "", value)
+
+
+        # setup listener on UserContact.phone attribute, instructing
+        # it to use the return value
+        listen(UserContact.phone, "set", validate_phone, retval=True)
+
+    A validation function like the above can also raise an exception
+    such as :exc:`ValueError` to halt the operation.
+
+    The :paramref:`.AttributeEvents.propagate` flag is also important when
+    applying listeners to mapped classes that also have mapped subclasses,
+    as when using mapper inheritance patterns::
+
+
+        @event.listens_for(MySuperClass.attr, "set", propagate=True)
+        def receive_set(target, value, initiator):
+            print("value set: %s" % target)
+
+    The full list of modifiers available to the :func:`.event.listen`
+    and :func:`.event.listens_for` functions are below.
+
+    :param active_history=False: When True, indicates that the
+      "set" event would like to receive the "old" value being
+      replaced unconditionally, even if this requires firing off
+      database loads. Note that ``active_history`` can also be
+      set directly via :func:`.column_property` and
+      :func:`_orm.relationship`.
+
+    :param propagate=False: When True, the listener function will
+      be established not just for the class attribute given, but
+      for attributes of the same name on all current subclasses
+      of that class, as well as all future subclasses of that
+      class, using an additional listener that listens for
+      instrumentation events.
+    :param raw=False: When True, the "target" argument to the
+      event will be the :class:`.InstanceState` management
+      object, rather than the mapped instance itself.
+    :param retval=False: when True, the user-defined event
+      listening must return the "value" argument from the
+      function.  This gives the listening function the opportunity
+      to change the value that is ultimately used for a "set"
+      or "append" event.
+
+    """
+
+    _target_class_doc = "SomeClass.some_attribute"
+    _dispatch_target = QueryableAttribute
+
+    @staticmethod
+    def _set_dispatch(
+        cls: Type[_HasEventsDispatch[Any]], dispatch_cls: Type[_Dispatch[Any]]
+    ) -> _Dispatch[Any]:
+        dispatch = event.Events._set_dispatch(cls, dispatch_cls)
+        dispatch_cls._active_history = False
+        return dispatch
+
+    @classmethod
+    def _accept_with(
+        cls,
+        target: Union[QueryableAttribute[Any], Type[QueryableAttribute[Any]]],
+        identifier: str,
+    ) -> Union[QueryableAttribute[Any], Type[QueryableAttribute[Any]]]:
+        # TODO: coverage
+        if isinstance(target, interfaces.MapperProperty):
+            return getattr(target.parent.class_, target.key)
+        else:
+            return target
+
+    @classmethod
+    def _listen(  # type: ignore [override]
+        cls,
+        event_key: _EventKey[QueryableAttribute[Any]],
+        active_history: bool = False,
+        raw: bool = False,
+        retval: bool = False,
+        propagate: bool = False,
+        include_key: bool = False,
+    ) -> None:
+        target, fn = event_key.dispatch_target, event_key._listen_fn
+
+        if active_history:
+            target.dispatch._active_history = True
+
+        if not raw or not retval or not include_key:
+
+            def wrap(target: InstanceState[_O], *arg: Any, **kw: Any) -> Any:
+                if not raw:
+                    target = target.obj()  # type: ignore [assignment]
+                if not retval:
+                    if arg:
+                        value = arg[0]
+                    else:
+                        value = None
+                    if include_key:
+                        fn(target, *arg, **kw)
+                    else:
+                        fn(target, *arg)
+                    return value
+                else:
+                    if include_key:
+                        return fn(target, *arg, **kw)
+                    else:
+                        return fn(target, *arg)
+
+            event_key = event_key.with_wrapper(wrap)
+
+        event_key.base_listen(propagate=propagate)
+
+        if propagate:
+            manager = instrumentation.manager_of_class(target.class_)
+
+            for mgr in manager.subclass_managers(True):  # type: ignore [no-untyped-call] # noqa: E501
+                event_key.with_dispatch_target(mgr[target.key]).base_listen(
+                    propagate=True
+                )
+                if active_history:
+                    mgr[target.key].dispatch._active_history = True
+
+    def append(
+        self,
+        target: _O,
+        value: _T,
+        initiator: Event,
+        *,
+        key: EventConstants = NO_KEY,
+    ) -> Optional[_T]:
+        """Receive a collection append event.
+
+        The append event is invoked for each element as it is appended
+        to the collection.  This occurs for single-item appends as well
+        as for a "bulk replace" operation.
+
+        :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 appended.  If this listener
+          is registered with ``retval=True``, the listener
+          function must return this value, or a new value which
+          replaces it.
+        :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, as well as be inspected for information
+          about the source of the event.
+        :param key: When the event is established using the
+         :paramref:`.AttributeEvents.include_key` parameter set to
+         True, this will be the key used in the operation, such as
+         ``collection[some_key_or_index] = value``.
+         The parameter is not passed
+         to the event at all if the the
+         :paramref:`.AttributeEvents.include_key`
+         was not used to set up the event; this is to allow backwards
+         compatibility with existing event handlers that don't include the
+         ``key`` parameter.
+
+         .. versionadded:: 2.0
+
+        :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.
+
+            :meth:`.AttributeEvents.bulk_replace`
+
+        """
+
+    def append_wo_mutation(
+        self,
+        target: _O,
+        value: _T,
+        initiator: Event,
+        *,
+        key: EventConstants = NO_KEY,
+    ) -> None:
+        """Receive a collection append event where the collection was not
+        actually mutated.
+
+        This event differs from :meth:`_orm.AttributeEvents.append` in that
+        it is fired off for de-duplicating collections such as sets and
+        dictionaries, when the object already exists in the target collection.
+        The event does not have a return value and the identity of the
+        given object cannot be changed.
+
+        The event is used for cascading objects into a :class:`_orm.Session`
+        when the collection has already been mutated via a backref 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 that would be appended if the object did not
+          already exist in the collection.
+        :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, as well as be inspected for information
+          about the source of the event.
+        :param key: When the event is established using the
+         :paramref:`.AttributeEvents.include_key` parameter set to
+         True, this will be the key used in the operation, such as
+         ``collection[some_key_or_index] = value``.
+         The parameter is not passed
+         to the event at all if the the
+         :paramref:`.AttributeEvents.include_key`
+         was not used to set up the event; this is to allow backwards
+         compatibility with existing event handlers that don't include the
+         ``key`` parameter.
+
+         .. versionadded:: 2.0
+
+        :return: No return value is defined for this event.
+
+        .. versionadded:: 1.4.15
+
+        """
+
+    def bulk_replace(
+        self,
+        target: _O,
+        values: Iterable[_T],
+        initiator: Event,
+        *,
+        keys: Optional[Iterable[EventConstants]] = None,
+    ) -> None:
+        """Receive a collection 'bulk replace' event.
+
+        This event is invoked for a sequence of values as they are incoming
+        to a bulk collection set operation, which can be
+        modified in place before the values are treated as ORM objects.
+        This is an "early hook" that runs before the bulk replace routine
+        attempts to reconcile which objects are already present in the
+        collection and which are being removed by the net replace operation.
+
+        It is typical that this method be combined with use of the
+        :meth:`.AttributeEvents.append` event.    When using both of these
+        events, note that a bulk replace operation will invoke
+        the :meth:`.AttributeEvents.append` event for all new items,
+        even after :meth:`.AttributeEvents.bulk_replace` has been invoked
+        for the collection as a whole.  In order to determine if an
+        :meth:`.AttributeEvents.append` event is part of a bulk replace,
+        use the symbol :attr:`~.attributes.OP_BULK_REPLACE` to test the
+        incoming initiator::
+
+            from sqlalchemy.orm.attributes import OP_BULK_REPLACE
+
+
+            @event.listens_for(SomeObject.collection, "bulk_replace")
+            def process_collection(target, values, initiator):
+                values[:] = [_make_value(value) for value in values]
+
+
+            @event.listens_for(SomeObject.collection, "append", retval=True)
+            def process_collection(target, value, initiator):
+                # make sure bulk_replace didn't already do it
+                if initiator is None or initiator.op is not OP_BULK_REPLACE:
+                    return _make_value(value)
+                else:
+                    return value
+
+        .. versionadded:: 1.2
+
+        :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: a sequence (e.g. a list) of the values being set.  The
+          handler can modify this list in place.
+        :param initiator: An instance of :class:`.attributes.Event`
+          representing the initiation of the event.
+        :param keys: When the event is established using the
+         :paramref:`.AttributeEvents.include_key` parameter set to
+         True, this will be the sequence of keys used in the operation,
+         typically only for a dictionary update.  The parameter is not passed
+         to the event at all if the the
+         :paramref:`.AttributeEvents.include_key`
+         was not used to set up the event; this is to allow backwards
+         compatibility with existing event handlers that don't include the
+         ``key`` parameter.
+
+         .. versionadded:: 2.0
+
+        .. seealso::
+
+            :class:`.AttributeEvents` - background on listener options such
+            as propagation to subclasses.
+
+
+        """
+
+    def remove(
+        self,
+        target: _O,
+        value: _T,
+        initiator: Event,
+        *,
+        key: EventConstants = NO_KEY,
+    ) -> None:
+        """Receive a collection remove 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 removed.
+        :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.
+
+        :param key: When the event is established using the
+         :paramref:`.AttributeEvents.include_key` parameter set to
+         True, this will be the key used in the operation, such as
+         ``del collection[some_key_or_index]``.  The parameter is not passed
+         to the event at all if the the
+         :paramref:`.AttributeEvents.include_key`
+         was not used to set up the event; this is to allow backwards
+         compatibility with existing event handlers that don't include the
+         ``key`` parameter.
+
+         .. versionadded:: 2.0
+
+        :return: No return value is defined for this event.
+
+
+        .. seealso::
+
+            :class:`.AttributeEvents` - background on listener options such
+            as propagation to subclasses.
+
+        """
+
+    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]
+    ) -> None:
+        r"""Receive a scalar "init" event.
+
+        This event is invoked when an uninitialized, unpersisted scalar
+        attribute is accessed, e.g. read::
+
+
+            x = my_object.some_attribute
+
+        The ORM's default behavior when this occurs for an un-initialized
+        attribute is to return the value ``None``; note this differs from
+        Python's usual behavior of raising ``AttributeError``.    The
+        event here can be used to customize what value is actually returned,
+        with the assumption that the event listener would be mirroring
+        a default generator that is configured on the Core
+        :class:`_schema.Column`
+        object as well.
+
+        Since a default generator on a :class:`_schema.Column`
+        might also produce
+        a changing value such as a timestamp, the
+        :meth:`.AttributeEvents.init_scalar`
+        event handler can also be used to **set** the newly returned value, so
+        that a Core-level default generation function effectively fires off
+        only once, but at the moment the attribute is accessed on the
+        non-persisted object.   Normally, no change to the object's state
+        is made when an uninitialized attribute is accessed (much older
+        SQLAlchemy versions did in fact change the object's state).
+
+        If a default generator on a column returned a particular constant,
+        a handler might be used as follows::
+
+            SOME_CONSTANT = 3.1415926
+
+
+            class MyClass(Base):
+                # ...
+
+                some_attribute = Column(Numeric, default=SOME_CONSTANT)
+
+
+            @event.listens_for(
+                MyClass.some_attribute, "init_scalar", retval=True, propagate=True
+            )
+            def _init_some_attribute(target, dict_, value):
+                dict_["some_attribute"] = SOME_CONSTANT
+                return SOME_CONSTANT
+
+        Above, we initialize the attribute ``MyClass.some_attribute`` to the
+        value of ``SOME_CONSTANT``.   The above code includes the following
+        features:
+
+        * By setting the value ``SOME_CONSTANT`` in the given ``dict_``,
+          we indicate that this value is to be persisted to the database.
+          This supersedes the use of ``SOME_CONSTANT`` in the default generator
+          for the :class:`_schema.Column`.  The ``active_column_defaults.py``
+          example given at :ref:`examples_instrumentation` illustrates using
+          the same approach for a changing default, e.g. a timestamp
+          generator.    In this particular example, it is not strictly
+          necessary to do this since ``SOME_CONSTANT`` would be part of the
+          INSERT statement in either case.
+
+        * By establishing the ``retval=True`` flag, the value we return
+          from the function will be returned by the attribute getter.
+          Without this flag, the event is assumed to be a passive observer
+          and the return value of our function is ignored.
+
+        * The ``propagate=True`` flag is significant if the mapped class
+          includes inheriting subclasses, which would also make use of this
+          event listener.  Without this flag, an inheriting subclass will
+          not use our event handler.
+
+        In the above example, the attribute set event
+        :meth:`.AttributeEvents.set` as well as the related validation feature
+        provided by :obj:`_orm.validates` is **not** invoked when we apply our
+        value to the given ``dict_``.  To have these events to invoke in
+        response to our newly generated value, apply the value to the given
+        object as a normal attribute set operation::
+
+            SOME_CONSTANT = 3.1415926
+
+
+            @event.listens_for(
+                MyClass.some_attribute, "init_scalar", retval=True, propagate=True
+            )
+            def _init_some_attribute(target, dict_, value):
+                # will also fire off attribute set events
+                target.some_attribute = SOME_CONSTANT
+                return SOME_CONSTANT
+
+        When multiple listeners are set up, the generation of the value
+        is "chained" from one listener to the next by passing the value
+        returned by the previous listener that specifies ``retval=True``
+        as the ``value`` argument of the next listener.
+
+        :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 that is to be returned before this event
+         listener were invoked.  This value begins as the value ``None``,
+         however will be the return value of the previous event handler
+         function if multiple listeners are present.
+        :param dict\_: the attribute dictionary of this mapped object.
+         This is normally the ``__dict__`` of the object, but in all cases
+         represents the destination that the attribute system uses to get
+         at the actual value of this attribute.  Placing the value in this
+         dictionary has the effect that the value will be used in the
+         INSERT statement generated by the unit of work.
+
+
+        .. seealso::
+
+            :meth:`.AttributeEvents.init_collection` - collection version
+            of this event
+
+            :class:`.AttributeEvents` - background on listener options such
+            as propagation to subclasses.
+
+            :ref:`examples_instrumentation` - see the
+            ``active_column_defaults.py`` example.
+
+        """  # noqa: E501
+
+    def init_collection(
+        self,
+        target: _O,
+        collection: Type[Collection[Any]],
+        collection_adapter: CollectionAdapter,
+    ) -> None:
+        """Receive a 'collection init' event.
+
+        This event is triggered for a collection-based attribute, when
+        the initial "empty collection" is first generated for a blank
+        attribute, as well as for when the collection is replaced with
+        a new one, such as via a set event.
+
+        E.g., given that ``User.addresses`` is a relationship-based
+        collection, the event is triggered here::
+
+            u1 = User()
+            u1.addresses.append(a1)  #  <- new collection
+
+        and also during replace operations::
+
+            u1.addresses = [a2, a3]  #  <- new collection
+
+        :param target: the object instance receiving the event.
+         If the listener is registered with ``raw=True``, this will
+         be the :class:`.InstanceState` object.
+        :param collection: the new collection.  This will always be generated
+         from what was specified as
+         :paramref:`_orm.relationship.collection_class`, and will always
+         be empty.
+        :param collection_adapter: the :class:`.CollectionAdapter` that will
+         mediate internal access to the collection.
+
+        .. seealso::
+
+            :class:`.AttributeEvents` - background on listener options such
+            as propagation to subclasses.
+
+            :meth:`.AttributeEvents.init_scalar` - "scalar" version of this
+            event.
+
+        """
+
+    def dispose_collection(
+        self,
+        target: _O,
+        collection: Collection[Any],
+        collection_adapter: CollectionAdapter,
+    ) -> None:
+        """Receive a 'collection dispose' event.
+
+        This event is triggered for a collection-based attribute when
+        a collection is replaced, that is::
+
+            u1.addresses.append(a1)
+
+            u1.addresses = [a2, a3]  # <- old collection is disposed
+
+        The old collection received will contain its previous contents.
+
+        .. versionchanged:: 1.2 The collection passed to
+           :meth:`.AttributeEvents.dispose_collection` will now have its
+           contents before the dispose intact; previously, the collection
+           would be empty.
+
+        .. seealso::
+
+            :class:`.AttributeEvents` - background on listener options such
+            as propagation to subclasses.
+
+        """
+
+    def modified(self, target: _O, initiator: Event) -> None:
+        """Receive a 'modified' event.
+
+        This event is triggered when the :func:`.attributes.flag_modified`
+        function is used to trigger a modify event on an attribute without
+        any specific value being set.
+
+        .. versionadded:: 1.2
+
+        :param target: the object instance receiving the event.
+          If the listener is registered with ``raw=True``, this will
+          be the :class:`.InstanceState` object.
+
+        :param initiator: An instance of :class:`.attributes.Event`
+          representing the initiation of the event.
+
+        .. seealso::
+
+            :class:`.AttributeEvents` - background on listener options such
+            as propagation to subclasses.
+
+        """
+
+
+class QueryEvents(event.Events[Query[Any]]):
+    """Represent events within the construction of a :class:`_query.Query`
+    object.
+
+    .. legacy:: The :class:`_orm.QueryEvents` event methods are legacy
+        as of SQLAlchemy 2.0, and only apply to direct use of the
+        :class:`_orm.Query` object. They are not used for :term:`2.0 style`
+        statements. For events to intercept and modify 2.0 style ORM use,
+        use the :meth:`_orm.SessionEvents.do_orm_execute` hook.
+
+
+    The :class:`_orm.QueryEvents` hooks are now superseded by the
+    :meth:`_orm.SessionEvents.do_orm_execute` event hook.
+
+    """
+
+    _target_class_doc = "SomeQuery"
+    _dispatch_target = Query
+
+    def before_compile(self, query: Query[Any]) -> None:
+        """Receive the :class:`_query.Query`
+        object before it is composed into a
+        core :class:`_expression.Select` object.
+
+        .. deprecated:: 1.4  The :meth:`_orm.QueryEvents.before_compile` event
+           is superseded by the much more capable
+           :meth:`_orm.SessionEvents.do_orm_execute` hook.   In version 1.4,
+           the :meth:`_orm.QueryEvents.before_compile` event is **no longer
+           used** for ORM-level attribute loads, such as loads of deferred
+           or expired attributes as well as relationship loaders.   See the
+           new examples in :ref:`examples_session_orm_events` which
+           illustrate new ways of intercepting and modifying ORM queries
+           for the most common purpose of adding arbitrary filter criteria.
+
+
+        This event is intended to allow changes to the query given::
+
+            @event.listens_for(Query, "before_compile", retval=True)
+            def no_deleted(query):
+                for desc in query.column_descriptions:
+                    if desc["type"] is User:
+                        entity = desc["entity"]
+                        query = query.filter(entity.deleted == False)
+                return query
+
+        The event should normally be listened with the ``retval=True``
+        parameter set, so that the modified query may be returned.
+
+        The :meth:`.QueryEvents.before_compile` event by default
+        will disallow "baked" queries from caching a query, if the event
+        hook returns a new :class:`_query.Query` object.
+        This affects both direct
+        use of the baked query extension as well as its operation within
+        lazy loaders and eager loaders for relationships.  In order to
+        re-establish the query being cached, apply the event adding the
+        ``bake_ok`` flag::
+
+            @event.listens_for(Query, "before_compile", retval=True, bake_ok=True)
+            def my_event(query):
+                for desc in query.column_descriptions:
+                    if desc["type"] is User:
+                        entity = desc["entity"]
+                        query = query.filter(entity.deleted == False)
+                return query
+
+        When ``bake_ok`` is set to True, the event hook will only be invoked
+        once, and not called for subsequent invocations of a particular query
+        that is being cached.
+
+        .. versionadded:: 1.3.11  - added the "bake_ok" flag to the
+           :meth:`.QueryEvents.before_compile` event and disallowed caching via
+           the "baked" extension from occurring for event handlers that
+           return  a new :class:`_query.Query` object if this flag is not set.
+
+        .. seealso::
+
+            :meth:`.QueryEvents.before_compile_update`
+
+            :meth:`.QueryEvents.before_compile_delete`
+
+            :ref:`baked_with_before_compile`
+
+        """  # noqa: E501
+
+    def before_compile_update(
+        self, query: Query[Any], update_context: BulkUpdate
+    ) -> None:
+        """Allow modifications to the :class:`_query.Query` object within
+        :meth:`_query.Query.update`.
+
+        .. deprecated:: 1.4  The :meth:`_orm.QueryEvents.before_compile_update`
+           event is superseded by the much more capable
+           :meth:`_orm.SessionEvents.do_orm_execute` hook.
+
+        Like the :meth:`.QueryEvents.before_compile` event, if the event
+        is to be used to alter the :class:`_query.Query` object, it should
+        be configured with ``retval=True``, and the modified
+        :class:`_query.Query` object returned, as in ::
+
+            @event.listens_for(Query, "before_compile_update", retval=True)
+            def no_deleted(query, update_context):
+                for desc in query.column_descriptions:
+                    if desc["type"] is User:
+                        entity = desc["entity"]
+                        query = query.filter(entity.deleted == False)
+
+                        update_context.values["timestamp"] = datetime.datetime.now(
+                            datetime.UTC
+                        )
+                return query
+
+        The ``.values`` dictionary of the "update context" object can also
+        be modified in place as illustrated above.
+
+        :param query: a :class:`_query.Query` instance; this is also
+         the ``.query`` attribute of the given "update context"
+         object.
+
+        :param update_context: an "update context" object which is
+         the same kind of object as described in
+         :paramref:`.QueryEvents.after_bulk_update.update_context`.
+         The object has a ``.values`` attribute in an UPDATE context which is
+         the dictionary of parameters passed to :meth:`_query.Query.update`.
+         This
+         dictionary can be modified to alter the VALUES clause of the
+         resulting UPDATE statement.
+
+        .. versionadded:: 1.2.17
+
+        .. seealso::
+
+            :meth:`.QueryEvents.before_compile`
+
+            :meth:`.QueryEvents.before_compile_delete`
+
+
+        """  # noqa: E501
+
+    def before_compile_delete(
+        self, query: Query[Any], delete_context: BulkDelete
+    ) -> None:
+        """Allow modifications to the :class:`_query.Query` object within
+        :meth:`_query.Query.delete`.
+
+        .. deprecated:: 1.4  The :meth:`_orm.QueryEvents.before_compile_delete`
+           event is superseded by the much more capable
+           :meth:`_orm.SessionEvents.do_orm_execute` hook.
+
+        Like the :meth:`.QueryEvents.before_compile` event, this event
+        should be configured with ``retval=True``, and the modified
+        :class:`_query.Query` object returned, as in ::
+
+            @event.listens_for(Query, "before_compile_delete", retval=True)
+            def no_deleted(query, delete_context):
+                for desc in query.column_descriptions:
+                    if desc["type"] is User:
+                        entity = desc["entity"]
+                        query = query.filter(entity.deleted == False)
+                return query
+
+        :param query: a :class:`_query.Query` instance; this is also
+         the ``.query`` attribute of the given "delete context"
+         object.
+
+        :param delete_context: a "delete context" object which is
+         the same kind of object as described in
+         :paramref:`.QueryEvents.after_bulk_delete.delete_context`.
+
+        .. versionadded:: 1.2.17
+
+        .. seealso::
+
+            :meth:`.QueryEvents.before_compile`
+
+            :meth:`.QueryEvents.before_compile_update`
+
+
+        """
+
+    @classmethod
+    def _listen(
+        cls,
+        event_key: _EventKey[_ET],
+        retval: bool = False,
+        bake_ok: bool = False,
+        **kw: Any,
+    ) -> None:
+        fn = event_key._listen_fn
+
+        if not retval:
+
+            def wrap(*arg: Any, **kw: Any) -> Any:
+                if not retval:
+                    query = arg[0]
+                    fn(*arg, **kw)
+                    return query
+                else:
+                    return fn(*arg, **kw)
+
+            event_key = event_key.with_wrapper(wrap)
+        else:
+            # don't assume we can apply an attribute to the callable
+            def wrap(*arg: Any, **kw: Any) -> Any:
+                return fn(*arg, **kw)
+
+            event_key = event_key.with_wrapper(wrap)
+
+        wrap._bake_ok = bake_ok  # type: ignore [attr-defined]
+
+        event_key.base_listen(**kw)