test_querysetsequence.py 文件源码

def test_empty(self):
        """
        Ensure that filter() works when it results in an empty QuerySet.
        """
        # Filter to nothing.
        with self.assertNumQueries(0):
            qss = self.all.exclude(author__in=[self.alice, self.bob])
        self.assertEqual(qss.count(), 0)
        self.assertIsInstance(qss, QuerySetSequence)

        # This should not throw an exception.
        data = list(qss)
        self.assertEqual(len(data), 0)