Method collect

celery/result.py:274–321

Collect results as they return. Iterator, like :meth:`get` will wait for the task to complete, but will also follow :class:`AsyncResult` and :class:`ResultSet` returned by the task, yielding ``(result, value)`` tuples for each result in the tree. An example

(self, intermediate=False, **kwargs)

            node = node.parent

    def collect(self, intermediate=False, **kwargs):
        """Collect results as they return.

        Iterator, like :meth:`get` will wait for the task to complete,
        but will also follow :class:`AsyncResult` and :class:`ResultSet`
        returned by the task, yielding ``(result, value)`` tuples for each
        result in the tree.

        An example would be having the following tasks:

        .. code-block:: python

            from celery import group
            from proj.celery import app

            @app.task(trail=True)
            def A(how_many):
                return group(B.s(i) for i in range(how_many))()

            @app.task(trail=True)
            def B(i):
                return pow2.delay(i)

            @app.task(trail=True)
            def pow2(i):
                return i ** 2

        .. code-block:: pycon

            >>> from celery.result import ResultBase
            >>> from proj.tasks import A

            >>> result = A.delay(10)
            >>> [v for v in result.collect()
            ...  if not isinstance(v, (ResultBase, tuple))]
            [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

        Note:
            The ``Task.trail`` option must be enabled
            so that the list of children is stored in ``result.children``.
            This is the default but enabled explicitly for illustration.

        Yields:
            Tuple[AsyncResult, Any]: tuples containing the result instance
            of the child task, and the return value of that task.
        """
        for _, R in self.iterdeps(intermediate=intermediate):
            yield R, R.get(**kwargs)

    def get_leaf(self):
        value = None