Class SequenceWithoutALength

Lib/test/test_builtin.py:2175–2180

        # result list when one of its arguments doesn't say how long it is.
        # A MemoryError is the most likely failure mode.
        class SequenceWithoutALength:
            def __getitem__(self, i):
                if i == 5:
                    raise IndexError
                else:
                    return i
        self.assertEqual(
            list(zip(SequenceWithoutALength(), range(2**30))),
            list(enumerate(range(5)))