Airflow DAG Loop - 如何使每次迭代顺序而不是并行

Question

我有一个 Apache Airflow DAG，如下所示:

DAG_NAME='my_dag'
sections = ["0", "1", "2", "3"]

with DAG(DAG_NAME, default_args=default_args, schedule_interval=None) as dag:

        for s in sections:
            a = DummyOperator(task_id=f"section_{s}_start")
            b = SubDagOperator(task_id=f"init_{s}_subdag",subdag=init_section(DAG_NAME,f"init_{s}_subdag", default_args))
            c = SubDagOperator(task_id=f"process_{s}_subdag", subdag=process_section(DAG_NAME,f"process_{s}_subdag", default_args))
            d = SubDagOperator(task_id=f"update_{s}_subdag", subdag=update_section(DAG_NAME,f"update_{s}_subdag", default_args))
            e = DummyOperator(task_id=f"section_{s}_end")
            a>>b>>c>>d>>e

这段代码像这样呈现我的任务

我怎样才能使任务序列是:
section_0_start>>init_0_subdag>>process_0_subdag>>update_0_subdag>>section_0_end
section_0_end>>section_1_start
section_1_start>>init_1_subdag>>process_1_subdag>>update_1_subdag>>section_1_end
.....
依此类推，从第 0 部分到第 3 部分任务结束
谢谢

Answer 1

像这样修改for循环:

    previous_e = None
    for s in sections:
        a = ...
        ...
        e = ...
        if previous_e:
            previous_e >> a
        a>>b>>c>>d>>e
        previous_e = e