How to create a simple scheduler in Django

If you need to run a function every X minutes/seconds etc. to do some cleanups, trigger some operations you can do a simple scheduler with the help of threading module and django custom cli commands.

Let's say I want to invoke a function every 5 seconds to post something on an external API.

In your django app create a folder/package named management inside that folder create another folder named commands. In the commands folder create a module named runposter.py. In the end you'll have something like this structure yourapp/management/commands/runposter.py.

In this code we use a thread which runs a while loop as long as it's not stopped every 5 seconds. Replace print("posting") with the function/logic you want to run.

# runposter.py
import time
from threading import Thread, Event
from django.conf import settings
from django.core.management.base import BaseCommand


stop_event = Event()


def my_job():
    while not stop_event.is_set():
        try:
            print("posting")
            time.sleep(5)
        except KeyboardInterrupt:
            break
        except Exception as err:
            print(err)
            continue



class Command(BaseCommand):
    help = "Run Poster."

    def handle(self, *args, **options):

        poster = Thread(target=my_job)

        try:
            print("Starting poster...")
            poster.start()
            while poster.is_alive():
                poster.join(timeout=1)
        except KeyboardInterrupt:
            print("Stopping poster...")
            stop_event.set()
            poster.join()
            print("Poster shut down successfully!")

Nice, now open another terminal window and run python manage.py runposter. Command runposter as you can see was created from the module name we've given.

Of course, for something more complex I recommend using rq-scheduler or celery periodic tasks or django-q.

But, for simple cases this should be good enough.