This document describes the current stable version of Celery (5.2). For development docs, go here.

Source code for celery.states

"""Built-in task states.

.. _states:

States
------

See :ref:`task-states`.

.. _statesets:

Sets
----

.. state:: READY_STATES

READY_STATES
~~~~~~~~~~~~

Set of states meaning the task result is ready (has been executed).

.. state:: UNREADY_STATES

UNREADY_STATES
~~~~~~~~~~~~~~

Set of states meaning the task result is not ready (hasn't been executed).

.. state:: EXCEPTION_STATES

EXCEPTION_STATES
~~~~~~~~~~~~~~~~

Set of states meaning the task returned an exception.

.. state:: PROPAGATE_STATES

PROPAGATE_STATES
~~~~~~~~~~~~~~~~

Set of exception states that should propagate exceptions to the user.

.. state:: ALL_STATES

ALL_STATES
~~~~~~~~~~

Set of all possible states.

Misc
----

"""

__all__ = (
    'PENDING', 'RECEIVED', 'STARTED', 'SUCCESS', 'FAILURE',
    'REVOKED', 'RETRY', 'IGNORED', 'READY_STATES', 'UNREADY_STATES',
    'EXCEPTION_STATES', 'PROPAGATE_STATES', 'precedence', 'state',
)

#: State precedence.
#: None represents the precedence of an unknown state.
#: Lower index means higher precedence.
PRECEDENCE = [
    'SUCCESS',
    'FAILURE',
    None,
    'REVOKED',
    'STARTED',
    'RECEIVED',
    'REJECTED',
    'RETRY',
    'PENDING',
]

#: Hash lookup of PRECEDENCE to index
PRECEDENCE_LOOKUP = dict(zip(PRECEDENCE, range(0, len(PRECEDENCE))))
NONE_PRECEDENCE = PRECEDENCE_LOOKUP[None]


[docs]def precedence(state: str) -> int: """Get the precedence index for state. Lower index means higher precedence. """ try: return PRECEDENCE_LOOKUP[state] except KeyError: return NONE_PRECEDENCE
[docs]class state(str): """Task state. State is a subclass of :class:`str`, implementing comparison methods adhering to state precedence rules:: >>> from celery.states import state, PENDING, SUCCESS >>> state(PENDING) < state(SUCCESS) True Any custom state is considered to be lower than :state:`FAILURE` and :state:`SUCCESS`, but higher than any of the other built-in states:: >>> state('PROGRESS') > state(STARTED) True >>> state('PROGRESS') > state('SUCCESS') False """ def __gt__(self, other: str) -> bool: return precedence(self) < precedence(other) def __ge__(self, other: str) -> bool: return precedence(self) <= precedence(other) def __lt__(self, other: str) -> bool: return precedence(self) > precedence(other) def __le__(self, other: str) -> bool: return precedence(self) >= precedence(other)
#: Task state is unknown (assumed pending since you know the id). PENDING = 'PENDING' #: Task was received by a worker (only used in events). RECEIVED = 'RECEIVED' #: Task was started by a worker (:setting:`task_track_started`). STARTED = 'STARTED' #: Task succeeded SUCCESS = 'SUCCESS' #: Task failed FAILURE = 'FAILURE' #: Task was revoked. REVOKED = 'REVOKED' #: Task was rejected (only used in events). REJECTED = 'REJECTED' #: Task is waiting for retry. RETRY = 'RETRY' IGNORED = 'IGNORED' READY_STATES = frozenset({SUCCESS, FAILURE, REVOKED}) UNREADY_STATES = frozenset({PENDING, RECEIVED, STARTED, REJECTED, RETRY}) EXCEPTION_STATES = frozenset({RETRY, FAILURE, REVOKED}) PROPAGATE_STATES = frozenset({FAILURE, REVOKED}) ALL_STATES = frozenset({ PENDING, RECEIVED, STARTED, SUCCESS, FAILURE, RETRY, REVOKED, })