turbaszek commented on a change in pull request #10153: URL: https://github.com/apache/airflow/pull/10153#discussion_r484260857
########## File path: airflow/example_dags/example_task_group.py ########## @@ -0,0 +1,59 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +"""Example DAG demonstrating the usage of the TaskGroup.""" + +from airflow.models.dag import DAG +from airflow.operators.dummy_operator import DummyOperator +from airflow.utils.dates import days_ago +from airflow.utils.task_group import TaskGroup + + +# [START howto_task_group] +def create_section(): + """ + Create tasks in the outer section. + """ + dummies = [DummyOperator(task_id=f'task-{i + 1}') for i in range(5)] + + with TaskGroup("inside_section_1") as inside_section_1: + _ = [DummyOperator(task_id=f'task-{i + 1}',) for i in range(3)] + + with TaskGroup("inside_section_2") as inside_section_2: + _ = [DummyOperator(task_id=f'task-{i + 1}',) for i in range(3)] + + dummies[-1] >> inside_section_1 + dummies[-2] >> inside_section_2 + inside_section_1 >> inside_section_2 + + +with DAG(dag_id="example_task_group", start_date=days_ago(2)) as dag: + start = DummyOperator(task_id="start") + + with TaskGroup("section_1", tooltip="Tasks for Section 1") as section_1: + create_section() + + some_other_task = DummyOperator(task_id="some-other-task") + + with TaskGroup("section_2", tooltip="Tasks for Section 2") as section_2: + create_section() + + end = DummyOperator(task_id='end') + + start >> section_1 >> some_other_task >> section_2 >> end +# [END howto_task_group] Review comment: It took me a while to understand this example. I would suggest to simplify it a bit by - avoiding `create_section` function and creating tasks explicitly - adding START/END for single `TaskGroup` section so users can grasp this as a single idea - adding START/END for `TaskGroup` within `TaskGroup` to demonstrate nesting Eventually, we may add another, simpler DAG next to this one. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected]
