| # 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. |
| from __future__ import annotations |
| |
| from datetime import datetime |
| |
| from airflow import DAG |
| from airflow.models.param import Param |
| from airflow.operators.python import PythonOperator |
| |
| with DAG( |
| "test_valid_param", |
| start_date=datetime(2021, 1, 1), |
| schedule=None, |
| params={ |
| # a string default is not mandatory as DAG has no schedule |
| "str_param": Param(type="string", minLength=2, maxLength=4), |
| # a string with None as default is also accepted as no schedule |
| "str_param2": Param(None, type="string", minLength=2, maxLength=4), |
| # But of course adding a valid default is also fine |
| "str_param3": Param("valid_default", type="string", minLength=2, maxLength=15), |
| }, |
| ) as the_dag: |
| |
| def print_these(*params): |
| for param in params: |
| print(param) |
| |
| PythonOperator( |
| task_id="ref_params", |
| python_callable=print_these, |
| op_args=[ |
| "{{ params.str_param }}", |
| ], |
| ) |