django-chard 0.1.1

A very simple async/await background task queue for Django.

Chard

Chard is a very simple async/await background task queue for Django. One process, no threads, no other dependencies.

It uses Django's ORM to keep track of tasks.

Not very efficient or battle tested. PRs are welcome!

Parts of this were inspired by dramatiq and django_dramatiq.

Requirements

• Python 3.8+
• Django 4.1+

Installation

pip install django-chard

Quickstart

First add chard anywhere in your INSTALLED_APPS setting and then run the migrations:

python manage.py migrate

Create a file called tasks.py in one of your apps and define a task:

import chard
import httpx
from asgiref.sync import sync_to_async

from .models import MyModel

@chard.task
async def my_task(country_code):
    url = f"https://somewhere.com/some-api.json?country_code={country_code}"
    async with httpx.AsyncClient() as client:
        resp = await client.get(url)
        obj = resp.json()
    for item in obj["items"]:
        await sync_to_async(MyModel.objects.create)(
          country_code=country_code,
          item=item
        )

To fire a task for the worker:

# Note that all arguments must be JSON serializable.
my_task.send("gb")

Run the worker process and it will watch for new pending tasks:

python manage.py chardworker

## Configuration

You can optionally place these in your settings.py:

# How many tasks can run concurrently (default: 10)
CHARD_MAX_CONCURRENT_TASKS = 50

# How long a task can run until it is forcibly canceled - setting this to
# to 0 means no timeout (default: 60)
CHARD_TIMEOUT = 30