Method test_repr_recursive_factory

Lib/test/test_defaultdict.py:207–220

(self)

        self.assertEqual(count, 2)

    def test_repr_recursive_factory(self):
        # gh-145492: defaultdict.__repr__ should not cause infinite recursion
        # when the factory's __repr__ calls repr() on the defaultdict.
        class ProblematicFactory:
            def __call__(self):
                return {}
            def __repr__(self):
                repr(dd)
                return f"ProblematicFactory for {dd}"

        dd = defaultdict(ProblematicFactory())
        # Should not raise RecursionError
        r = repr(dd)
        self.assertIn("ProblematicFactory for", r)

if __name__ == "__main__":
    unittest.main()