Source code for airflow.example_dags.example_branch_operator

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"""Example DAG demonstrating the usage of the BranchPythonOperator."""

import random

import pendulum

from airflow import DAG
from airflow.operators.empty import EmptyOperator
from airflow.operators.python import BranchPythonOperator
from airflow.utils.edgemodifier import Label
from airflow.utils.trigger_rule import TriggerRule

with DAG(
    dag_id='example_branch_operator',
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    catchup=False,
    schedule_interval="@daily",
    tags=['example', 'example2'],
) as dag:
[docs] run_this_first = EmptyOperator( task_id='run_this_first',
) options = ['branch_a', 'branch_b', 'branch_c', 'branch_d'] branching = BranchPythonOperator( task_id='branching', python_callable=lambda: random.choice(options), ) run_this_first >> branching join = EmptyOperator( task_id='join', trigger_rule=TriggerRule.NONE_FAILED_MIN_ONE_SUCCESS, ) for option in options: t = EmptyOperator( task_id=option, ) empty_follow = EmptyOperator( task_id='follow_' + option, ) # Label is optional here, but it can help identify more complex branches branching >> Label(option) >> t >> empty_follow >> join

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