formal shoal
This is best described by a tiny example: https://gitlab.com/offby1/django-tutorial/-/tree/8da79f6bab5edd98a33292a4370b9afee8e73b3b
If you clone that, and run poetry install --no-root, and then DJANGO_SETTINGS_MODULE=django_project.settings poetry run pytest demo/tests.py --create-db, you'll see the test fail.
My question is: why does it behave that way? Why doesn't the test pass? Is this behavior documented somewhere?
Because of this behavior, I find myself writing getattr(t, "bottle", None) more than I'd like to.
glass hollow
maybe try .save()
glass hollow
I would check whether the objects have been created
trim kernel
Does it make a difference if you explicitly set the related name?
formal shoal
gosh I hadn't noticed any of these replies!
formal shoal
maybe try `.save()`
which object should I save -- b or t?
formal shoal
Does it make a difference if you explicitly set the related name?
No.
glass hollow
which object should I save -- `b` or `t`?
try it with both
formal shoal
didn't help
so I'm not saying that the behavior is wrong; I'm saying it's surprising.
ember flame
if you "assert t.bottle is None" on line 6, before you create b, you will get the same exception that happens after b is deleted.
formal shoal
oho
indeed. Somehow that's less surprising. Lemme examine my own mind and see if I can articulate why 🙂
meanwhile, I'll ask: is there a cleaner way to do stuff with t.bottle than getattr(t, "bottle", None)?
ember flame
That's a good question. Using getattr seems easy to read and it will perform consistently and it uses less space than a try..except clause or a assertRaises. As for the "assert t.bottle is None", at least it is behaving consistently. I think that with "null=True" on the OneToOne relationship from Bottle to Thing that it would be reasonable to expect the reverse to be None if there is no relationship. I suppose there is a good reason for throwing an exception instead.