Class Session

lib/sqlalchemy/orm/session.py:1458–4928

Manages persistence operations for ORM-mapped objects. The :class:`_orm.Session` is **not safe for use in concurrent threads.**. See :ref:`session_faq_threadsafe` for background. The Session's usage paradigm is described at :doc:`/orm/session`.

class Session(_SessionClassMethods, EventTarget):
    """Manages persistence operations for ORM-mapped objects.

    The :class:`_orm.Session` is **not safe for use in concurrent threads.**.
    See :ref:`session_faq_threadsafe` for background.

    The Session's usage paradigm is described at :doc:`/orm/session`.


    """

    _is_asyncio = False

    dispatch: dispatcher[Session]

    identity_map: IdentityMap
    """A mapping of object identities to objects themselves.

    Iterating through ``Session.identity_map.values()`` provides
    access to the full set of persistent objects (i.e., those
    that have row identity) currently in the session.

    .. seealso::

        :func:`.identity_key` - helper function to produce the keys used
        in this dictionary.

    """

    _new: Dict[InstanceState[Any], Any]
    _deleted: Dict[InstanceState[Any], Any]
    bind: Optional[Union[Engine, Connection]]
    __binds: Dict[_SessionBindKey, _SessionBind]
    _flushing: bool
    _warn_on_events: bool
    _transaction: Optional[SessionTransaction]
    _nested_transaction: Optional[SessionTransaction]
    hash_key: int
    autoflush: bool
    expire_on_commit: bool
    enable_baked_queries: bool
    twophase: bool
    join_transaction_mode: JoinTransactionMode
    _query_cls: Type[Query[Any]]
    _close_state: _SessionCloseState

    def __init__(
        self,
        bind: Optional[_SessionBind] = None,
        *,
        autoflush: bool = True,
        future: Literal[True] = True,
        expire_on_commit: bool = True,
        autobegin: bool = True,
        twophase: bool = False,
        binds: Optional[Dict[_SessionBindKey, _SessionBind]] = None,
        enable_baked_queries: bool = True,
        info: Optional[_InfoType] = None,