Method test_zip

Lib/test/test_builtin.py:2150–2192

(self)

        return items

    def test_zip(self):
        a = (1, 2, 3)
        b = (4, 5, 6)
        t = [(1, 4), (2, 5), (3, 6)]
        self.assertEqual(list(zip(a, b)), t)
        b = [4, 5, 6]
        self.assertEqual(list(zip(a, b)), t)
        b = (4, 5, 6, 7)
        self.assertEqual(list(zip(a, b)), t)
        class I:
            def __getitem__(self, i):
                if i < 0 or i > 2: raise IndexError
                return i + 4
        self.assertEqual(list(zip(a, I())), t)
        self.assertEqual(list(zip()), [])
        self.assertEqual(list(zip(*[])), [])
        self.assertRaises(TypeError, zip, None)
        class G:
            pass
        self.assertRaises(TypeError, zip, a, G())
        self.assertRaises(RuntimeError, zip, a, TestFailingIter())

        # Make sure zip doesn't try to allocate a billion elements for the
        # 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)))
        )

        class BadSeq:
            def __getitem__(self, i):
                if i == 5:
                    raise ValueError
                else:
                    return i
        self.assertRaises(ValueError, list, zip(BadSeq(), BadSeq()))

    def test_zip_pickle(self):
        a = (1, 2, 3)