# -*- coding: utf-8 -*-
#
# Licensed to the Apache Software Foundation (ASF) under one
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# 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
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import airflow
from airflow.models import DAG
from airflow.operators.dummy_operator import DummyOperator
from airflow.operators.python_operator import BranchPythonOperator

args = {
    'owner': 'Airflow',
    'start_date': airflow.utils.dates.days_ago(2),
    'depends_on_past': True,
}

# BranchPython operator that depends on past
# and where tasks may run or be skipped on
# alternating runs
dag = DAG(
    dag_id='example_branch_dop_operator_v3',
    schedule_interval='*/1 * * * *',
    default_args=args,
)


def should_run(**kwargs):
    print('------------- exec dttm = {} and minute = {}'.
          format(kwargs['execution_date'], kwargs['execution_date'].minute))
    if kwargs['execution_date'].minute % 2 == 0:
        return "dummy_task_1"
    else:
        return "dummy_task_2"


cond = BranchPythonOperator(
    task_id='condition',
    provide_context=True,
    python_callable=should_run,
    dag=dag,
)

dummy_task_1 = DummyOperator(task_id='dummy_task_1', dag=dag)
dummy_task_2 = DummyOperator(task_id='dummy_task_2', dag=dag)
cond >> [dummy_task_1, dummy_task_2]
