rajrao commented on code in PR #34016: URL: https://github.com/apache/airflow/pull/34016#discussion_r1315041680
########## docs/apache-airflow/core-concepts/xcoms.rst: ########## @@ -25,9 +25,23 @@ XComs (short for "cross-communications") are a mechanism that let :doc:`tasks` t An XCom is identified by a ``key`` (essentially its name), as well as the ``task_id`` and ``dag_id`` it came from. They can have any (serializable) value, but they are only designed for small amounts of data; do not use them to pass around large values, like dataframes. -XComs are explicitly "pushed" and "pulled" to/from their storage using the ``xcom_push`` and ``xcom_pull`` methods on Task Instances. Many operators will auto-push their results into an XCom key called ``return_value`` if the ``do_xcom_push`` argument is set to ``True`` (as it is by default), and ``@task`` functions do this as well. +XComs are explicitly "pushed" and "pulled" to/from their storage using the ``xcom_push`` and ``xcom_pull`` methods on Task Instances. -``xcom_pull`` defaults to using this key if no key is passed to it, meaning it's possible to write code like this:: +To push a value within a task called **"task-1"** that will be used by another task: + +.. code-block:: python + + # pushes data in any_serializable_value into xcom with key "identifier as string" + task_instance.xcom_push(key="identifier as string", value=any_serializable_value) + +To pull the value that was pushed in the code above in a different task: + +.. code-block:: python + + # pulls the xcom variable with key "identifier as string" that was pushed from within task-1 + task_instance.xcom_pull(key="identifier as string", task_ids="task-1") + +Many operators will auto-push their results into an XCom key called ``return_value`` if the ``do_xcom_push`` argument is set to ``True`` (as it is by default), and ``@task`` functions do this as well. ``xcom_pull`` defaults to using ``return_value`` as key if no key is passed to it, meaning it's possible to write code like this:: Review Comment: do you mean change it from: value = task_instance.xcom_pull(task_ids='pushing_task') to value = task_instance.xcom_pull(task_ids='task-1') I like "pushing_task", as it gives the context that you are pulling a variable that was pushed from "pushing_task". -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@airflow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
