This document describes the current stable version of Celery (5.6). For development docs, go here.

# Source code for celery.app.registry

    """Registry of available tasks."""
    import inspect
    from importlib import import_module

    from celery._state import get_current_app
    from celery.app.autoretry import add_autoretry_behaviour
    from celery.exceptions import InvalidTaskError, NotRegistered

    __all__ = ('TaskRegistry',)

    class TaskRegistry(dict):
        """Map of registered tasks."""

        NotRegistered = NotRegistered

        def __missing__(self, key):
            raise self.NotRegistered(key)

        def register(self, task):
            """Register a task in the task registry.

            The task will be automatically instantiated if not already an
            instance. Name must be configured prior to registration.
            """
            if task.name is None:
                raise InvalidTaskError(
                    'Task class {!r} must specify .name attribute'.format(
                        type(task).__name__))
            task = inspect.isclass(task) and task() or task
            add_autoretry_behaviour(task)
            self[task.name] = task

        def unregister(self, name):
            """Unregister task by name.

            Arguments:
                name (str): name of the task to unregister, or a
                    :class:`celery.app.task.Task` with a valid `name` attribute.

            Raises:
                celery.exceptions.NotRegistered: if the task is not registered.
            """
            try:
                self.pop(getattr(name, 'name', name))
            except KeyError:
                raise self.NotRegistered(name)

        # -- these methods are irrelevant now and will be removed in 4.0

        def regular(self):
            return self.filter_types('regular')

        def periodic(self):
            return self.filter_types('periodic')

        def filter_types(self, type):
            return {name: task for name, task in self.items()
                    if getattr(task, 'type', 'regular') == type}

    def _unpickle_task(name):
        return get_current_app().tasks[name]

    def _unpickle_task_v2(name, module=None):
        if module:
            import_module(module)
        return get_current_app().tasks[name]