test_byteswap.py 文件源码

def test_struct_fields_2(self):
        # standard packing in struct uses no alignment.
        # So, we have to align using pad bytes.
        #
        # Unaligned accesses will crash Python (on those platforms that
        # don't allow it, like sparc solaris).
        if sys.byteorder == "little":
            base = BigEndianStructure
            fmt = ">bxhid"
        else:
            base = LittleEndianStructure
            fmt = "<bxhid"

        class S(base):
            _fields_ = [("b", c_byte),
                        ("h", c_short),
                        ("i", c_int),
                        ("d", c_double)]

        s1 = S(0x12, 0x1234, 0x12345678, 3.14)
        s2 = struct.pack(fmt, 0x12, 0x1234, 0x12345678, 3.14)
        self.assertEqual(bin(s1), bin(s2))