test_byteswap.py 文件源码

def test_endian_float(self):
        if sys.byteorder == "little":
            self.assertIs(c_float.__ctype_le__, c_float)
            self.assertIs(c_float.__ctype_be__.__ctype_le__, c_float)
        else:
            self.assertIs(c_float.__ctype_be__, c_float)
            self.assertIs(c_float.__ctype_le__.__ctype_be__, c_float)
        s = c_float(math.pi)
        self.assertEqual(bin(struct.pack("f", math.pi)), bin(s))
        # Hm, what's the precision of a float compared to a double?
        self.assertAlmostEqual(s.value, math.pi, 6)
        s = c_float.__ctype_le__(math.pi)
        self.assertAlmostEqual(s.value, math.pi, 6)
        self.assertEqual(bin(struct.pack("<f", math.pi)), bin(s))
        s = c_float.__ctype_be__(math.pi)
        self.assertAlmostEqual(s.value, math.pi, 6)
        self.assertEqual(bin(struct.pack(">f", math.pi)), bin(s))