Events framework for Python?
Solution 1
I decided Celery with RabbitMQ is the most mature software combination, and I will stick with them. Celery allows not just creating events, but flexible specialization via queue routing, and parallelization.
Solution 2
Check circuits: a Lightweight Event driven and Asynchronous Application Framework for the Python Programming Language with a strong Component Architecture.
Solution 3
Django ztaskd is a way of calling asynchronous tasks from Django via ZeroMQ (via pyzmq).
culebrón
My GitHub profile, my CV at careers. Erde: hiking-light geospatial toolkit I'm a Python & Javascript programmer, know some DBs well. Know some Linux stuff. I speak Russian, Italian, Spanish and English fluently. I'm fond of cycling, MTB orienteering, travelling.
Updated on June 04, 2022Comments
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culebrón almost 2 years
I'm building a system that works with web clients (Django) and remote APIs (probably a standalone daemon). I see it's easier to coordinate their work with some events framework like in JavaScript. Unfortunately, Django signals are synchronous, which will make replies to the clients very slow. Also, I might want to be able to migrate the daemon or its part to a separate machine, but still work the same way (not RPC, but just triggering an event or sending a message). (This might sound like Erlang's approach.)
Is there a framework that would use proven and reliable ways to communicate between processes (say, RabbitMQ), and require minimum boilerplate?
As for Twisted, that André Paramés suggested, I'd prefer a simpler code. Is this doable in Twisted?
from events_framework import subscribe, trigger from django.http import Client http_client = Client() # just a sample @subscribe('data_received'): def reply(data): http_client.post('http://www.example.com', data) trigger('data_resent', data)
Here are more details. There is a Django views file that uses some models and notifies others of events. And there is a standalone daemon script that runs infinitely and reacts to events.
This is just pseudo code, I only mean how easy it should be.
# django_project/views.py (a Django views file) from events_framework import publish, subscribe from annoying import @subscribe('settings_updated') def _on_settings_update(event): # listens to settings_updated event and saves the data Settings.object.get(user__id=event.user_id).update(event.new_settings) @render_to('form.html') def show_form(request): # triggers 'form_shown' event publish('form_shown', {'user_id': request.user.id, 'form_data': request.GET}) return {...} # script.py (a standalone script) from events_framework import publish, subscribe @subscribe('form_shown') def on_form_shown(event): # listens to form_shown event and triggers another event pass result = requests.get('third party url', some_data) publish('third_party_requested', {'result': result})
Again, this couldn't be done just with Django signals: some events need to be published over network, others should be local but asynchronous.
It may be necessary to do instantiate something, like
from events_framework import Environment env = Environment() # will connect to default rabbitmq server from settings.