# -*- coding: utf-8 -*-
#
# 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
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from __future__ import print_function
from builtins import range
import airflow
from airflow.operators.python_operator import PythonOperator
from airflow.models import DAG

import time
from pprint import pprint

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

dag = DAG(
    dag_id='example_python_operator', default_args=args,
    schedule_interval=None)


def my_sleeping_function(random_base):
    """This is a function that will run within the DAG execution"""
    time.sleep(random_base)


def print_context(ds, **kwargs):
    pprint(kwargs)
    print(ds)
    return 'Whatever you return gets printed in the logs'

run_this = PythonOperator(
    task_id='print_the_context',
    provide_context=True,
    python_callable=print_context,
    dag=dag)

# Generate 10 sleeping tasks, sleeping from 0 to 9 seconds respectively
for i in range(10):
    task = PythonOperator(
        task_id='sleep_for_' + str(i),
        python_callable=my_sleeping_function,
        op_kwargs={'random_base': float(i) / 10},
        dag=dag)

    task.set_upstream(run_this)
