Airflow DAG labels

On Airflow you can label dependencies between the tasks using the Label() object.

from airflow.utils.edgemodifier import Label

task_A >> Label("Transform") >> task_B

This become handy when you explicitly want to document the edges of your DAG (Direct Acyclic Graph) e.g. to indicate what is happening between the tasks.

Minimal Functional Example

from airflow import DAG
from airflow.decorators import task
from airflow.utils.edgemodifier import Label

from datetime import datetime

with DAG(
    dag_id="test-airflow-dag-label",
    start_date=datetime(2023, 1, 23),
    schedule_interval="@daily",
    catchup=False,
    tags=["test"],
) as dag:

    @task
    def task_A():
        ...

    @task
    def task_B():
        ...

    task_A() >> Label("Move data from A to B") >> task_B()

Note: the ... (ellipsis literal) is equivalent to pass.