How to pass parameter to PythonOperator in Airflow

Question

I just started using Airflow, can anyone enlighten me how to pass a parameter into PythonOperator like below:

t5_send_notification = PythonOperator(
    task_id='t5_send_notification',
    provide_context=True,
    python_callable=SendEmail,
    op_kwargs=None,
    #op_kwargs=(key1='value1', key2='value2'),
    dag=dag,
)

def SendEmail(**kwargs):
    msg = MIMEText("The pipeline for client1 is completed, please check.")
    msg['Subject'] = "xxxx"
    msg['From'] = "xxxx"
    ......
    s = smtplib.SMTP('localhost')
    s.send_message(msg)
    s.quit()

I would like to be able to pass some parameters into the t5_send_notification's callable which is SendEmail, ideally I want to attach the full log and/or part of the log (which is essentially from the kwargs) to the email to be sent out, guessing the t5_send_notification is the place to gather those information.

Thank you very much.

score 64 · Accepted Answer · answered Feb 26 '19 at 23:27

64

Pass a dict object to op_kwargs

Use the keys to access their value from kwargs dict in your python callable

def SendEmail(**kwargs):
    print(kwargs['key1'])
    print(kwargs['key2'])
    msg = MIMEText("The pipeline for client1 is completed, please check.")
    msg['Subject'] = "xxxx"
    msg['From'] = "xxxx"
    ......
    s = smtplib.SMTP('localhost')
    s.send_message(msg)
    s.quit()


t5_send_notification = PythonOperator(
    task_id='t5_send_notification',
    provide_context=True,
    python_callable=SendEmail,
    op_kwargs={'key1': 'value1', 'key2': 'value2'},
    dag=dag,
)

answered Feb 26 '19 at 23:27

Ryan Yuan

2,396
2
13
23

1

that didn't work. it should be like: `SendEmail(key1, key2, **kwargs):` – Amin Mar 17 '20 at 04:18
@Amin which version of the airflow you are using? the reason why I asked is that you might be using python3 as the latest versions of airflow support python3 much better than a year ago, but still there are lots of people using python2 for airflow dev. – Ryan Yuan Mar 17 '20 at 04:49
3

If it has something to do with python version please mention it in the answer. – Amin Mar 18 '20 at 05:45

score 19 · Answer 2 · edited Sep 10 '20 at 23:37

19

PythonOperator have a named parameter op_kwargs and accepts dict object.

have

t5_send_notification = PythonOperator(
    task_id='t5_send_notification',
    provide_context=True,
    python_callable=SendEmail,
    op_kwargs={"my_param":'value1'},
    dag=dag,
)

def SendEmail(my_param,**kwargs):
    print(my_param) #'value_1'
    msg = MIMEText("The pipeline for client1 is completed, please check.")
    msg['Subject'] = "xxxx"
    msg['From'] = "xxxx"
    ......
    s = smtplib.SMTP('localhost')
    s.send_me

edited Sep 10 '20 at 23:37

jahmia

65
1
10

answered Feb 26 '19 at 21:42

ethanenglish

1,217
2
15
32

2

Thank you Ethan, your code of `op_kwargs={my_param='value1'},` reports error. – mdivk Feb 27 '19 at 01:09
1

`{key : value}` – Joseph Seung Jae Dollar Jul 11 '19 at 16:03
Do you have the entire error? Is the key in quotes as well? – ethanenglish Jul 12 '19 at 19:18

How to pass parameter to PythonOperator in Airflow

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