airflow_719.py

from datetime import datetime

from airflow.models import DAG
from airflow.operators.dummy_operator import DummyOperator
from airflow.operators.latest_only_operator import LatestOnlyOperator

dag = DAG(dag_id='airflow_719', start_date=datetime(2017, 4, 1), schedule_interval='@hourly', catchup=True)

latest_only = LatestOnlyOperator(
    task_id='latest_only',
    dag=dag,
)

dummy1 = DummyOperator(
    task_id='dummy1',
    dag=dag,
)

dummy2 = DummyOperator(
    task_id='dummy2',
    dag=dag,
)

dummy3 = DummyOperator(
    task_id='dummy3',
    dag=dag,
)

latest_only >> dummy1 >> dummy2 >> dummy3

if __name__ == '__main__':
    dag.cli()