Method test_isqrt

Lib/test/test_math_integer.py:203–240

(self)

        self.assertEqual(lcm(MyIndexable(120), MyIndexable(84)), 840)

    def test_isqrt(self):
        isqrt = self.module.isqrt
        # Test a variety of inputs, large and small.
        test_values = (
            list(range(1000))
            + list(range(10**6 - 1000, 10**6 + 1000))
            + [2**e + i for e in range(60, 200) for i in range(-40, 40)]
            + [3**9999, 10**5001]
        )

        for value in test_values:
            with self.subTest(value=value):
                s = isqrt(value)
                self.assertIs(type(s), int)
                self.assertLessEqual(s*s, value)
                self.assertLess(value, (s+1)*(s+1))

        # Negative values
        with self.assertRaises(ValueError):
            isqrt(-1)

        # Integer-like things
        self.assertIntEqual(isqrt(True), 1)
        self.assertIntEqual(isqrt(False), 0)
        self.assertIntEqual(isqrt(MyIndexable(1729)), 41)

        with self.assertRaises(ValueError):
            isqrt(MyIndexable(-3))

        # Non-integer-like things
        bad_values = [
            3.5, "a string", Decimal("3.5"), 3.5j,
            100.0, -4.0,
        ]
        for value in bad_values:
            with self.subTest(value=value):
                with self.assertRaises(TypeError):
                    isqrt(value)

    @support.bigmemtest(2**32, memuse=0.85)
    def test_isqrt_huge(self, size):