Testing DELETE with django.test.Client

I want to be able to test various constraints that I have on my Django API.

I'm having difficulty doing this with the django.test.Client.

// prepare my_thing so it cannot be deleted
my_thing.save()

response = Client().delete('/my_things/%s/' % my_thing.id,
                             content_type='application/x-www-form-urlencoded')

self.assertEquals(204, response.status_code)

Even if the constraints prevent deletion, tests like this will pass successfully.

Is there a way to unit test Django constraints? I could write a test that uses requests but that would require the API to be running, which I don't want to require.