Location of signals in Django

I am confused about the use of signals. Where should I put the signal codes so that they are orderly and appropriate? I have a signal file for an app. Where do I call it?

I am confused about the use of signals. Where should I put the signal codes so that they are orderly and appropriate?

Often these are stored in a file named signals.py in the app directory. But that is not required at all.

I have a signal file for an app. Where do I call it?

You load it in the AppConfig which will load the module when the app is ready:

# my_app/apps.py

from django.apps import AppConfig


class MyAppConfig(AppConfig):
    name = 'my_app'
    verbose_name = 'My app name'

    def ready(self):
        import my_app.signals  # noqa

Signals are often a bad idea. Indeed, signals can be circumventing, for example with a .bulk_create(…) ^[Django-doc] that will not trigger signals for created objects. There are also a lot of scenarios where the data can change: creating records, updating records, removing records. It turns out that keeping the same data in sync, even on the same database, is not easy. I summarized some problems with signals in this article ^{[django-antipatterns]}.