Atomicity Documentation
To summarize, @transaction.atomic
will execute a transaction on the database if your view produces a response without errors. Because you’re catching the exception yourself, it appears to Django that your view executed just fine.
If you catch the exception, you need to handle it yourself: Controlling Transactions
If you need to produce a proper json response in the event of failure:
from django.db import SomeError, transaction
def viewfunc(request):
do_something()
try:
with transaction.atomic():
thing_that_might_fail()
except SomeError:
handle_exception()
render_response()