test_number.py 文件源码

def test_exact_log2(self):
        """Util.number.exact_log2"""
        self.assertRaises(TypeError, number.exact_log2, "0")
        self.assertRaises(ValueError, number.exact_log2, -1)
        self.assertRaises(ValueError, number.exact_log2, 0)
        self.assertEqual(0, number.exact_log2(1))
        self.assertEqual(1, number.exact_log2(2))
        self.assertRaises(ValueError, number.exact_log2, 3)
        self.assertEqual(2, number.exact_log2(4))
        self.assertRaises(ValueError, number.exact_log2, 5)
        self.assertRaises(ValueError, number.exact_log2, 6)
        self.assertRaises(ValueError, number.exact_log2, 7)
        e = 3
        n = 8
        while e < 16:
            if n == 2**e:
                self.assertEqual(e, number.exact_log2(n), "expected=2**%d, n=%d" % (e, n))
                e += 1
            else:
                self.assertRaises(ValueError, number.exact_log2, n)
            n += 1

        for e in range(16, 1+64, 2):
            self.assertRaises(ValueError, number.exact_log2, 2**e-1)
            self.assertEqual(e, number.exact_log2(2**e))
            self.assertRaises(ValueError, number.exact_log2, 2**e+1)