basic-dag.py

import datetime as dt

import requests

from airflow import DAG
from airflow.operators import PythonOperator


def extract(**kwargs):
    param = kwargs.get('param')
    r = requests.get("http://httpbin.org/get?query={}".format(param))
    print r.json()


def transform(**kwargs):
    print kwargs


def load(**kwargs):
    print kwargs


start_date = dt.datetime.strptime('2018-08-01T00:00:00', '%Y-%m-%dT%H:%M:%S')
with DAG(dag_id='my_dag', start_date=start_date) as dag:
    task1 = PythonOperator(task_id='extract', python_callable=extract, op_kwargs={'param': 'a'})
    task2 = PythonOperator(task_id='transform', python_callable=transform, op_kwargs={'foo': 'bar'})
    task3 = PythonOperator(task_id='load', python_callable=transform, op_kwargs={'bar': 'baz'})

    task2.set_upstream(task1)
    task3.set_upstream(task2)