Lee-W commented on code in PR #34016:
URL: https://github.com/apache/airflow/pull/34016#discussion_r1314563116
##########
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:
Should we add a similar example here?
##########
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)
Review Comment:
nitpick: I think it might be better for us to add an "a" before the string
or should we just name it as "identifier string"?
```suggestion
task_instance.xcom_push(key="identifier as a string",
value=any_serializable_value)
```
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