test_orm.py 文件源码

def test_get_one_does_not_iterate_long_sequence_indefinitely(self):
        # Avoid typical performance pitfall of retrieving all objects.
        # In rare failure cases, there may be large numbers.  Fail fast.

        class InfinityException(Exception):
            """Iteration went on indefinitely."""

        def infinite_sequence():
            """Generator: count to infinity (more or less), then fail."""
            for counter in range(3):
                yield counter
            raise InfinityException()

        # Raises MultipleObjectsReturned as spec'ed.  It does not
        # iterate to infinity first!
        self.assertRaises(
            MultipleObjectsReturned, get_one, infinite_sequence())