from __future__ import print_function
from ctypes import *

class SubByte(c_ubyte):
    def __repr__(self):
        return "%d" % self.value

class A(Structure):
    """A structure containing 2 bitfields of type unsigned byte."""
    _fields_ = [("lo", c_ubyte, 5),
                ("hi", c_ubyte, 3)]

class B(Structure):
    """The same structure containing 2 bitfields,
    but of type subclass of unsigned byte."""
    _fields_ = [("lo", SubByte, 5),
                ("hi", SubByte, 3)]

class TestStruct(Union):
    """This union allows access via the c_ubyte bit-fields
    or the SubByte bitfields.
    """
    _fields_ = [("a", A),
                ("b", B)]

t = TestStruct()

t.a.hi, t.a.lo = (7, 0)
print(t.a.hi, t.a.lo) # prints 7 0
print(t.b.hi, t.b.lo) # prints 224 224

t.a.hi, t.a.lo = (0, 31)
print(t.a.hi, t.a.lo) # prints 0 31
print(t.b.hi, t.b.lo) # prints 31 31

t.a.hi, t.a.lo = (7, 31)
print(t.a.hi, t.a.lo) # prints 7 31
print(t.b.hi, t.b.lo) # prints 255 255