Mine

import structclass Struct(object):	__slots__ = ('__attrs__', '__values__', '__def__', '__size__', '__cooked__')	int8 = ('b', 1)	uint8 = ('B', 1)		int16 = ('h', 2)	uint16 = ('H', 2)		int32 = ('l', 4)	uint32 = ('L', 4)		float = ('f', 4)		def __init__(self):		self.__attrs__ = []		self.__values__ = {}		self.__def__ = ''		self.__size__ = 0		self.__cooked__ = False		def __setattr__(self, name, value):		if name in self.__slots__:			return object.__setattr__(self, name, value)				if self.__cooked__ == False:			self.__def__ += value[0]			self.__size__ += value[1]			self.__attrs__.append(name)			self.__values__[name] = 0		else:			self.__values__[name] = value		def __getattr__(self, name):		return self.__values__[name]		def __cook__(self):		self.__cooked__ = True		return self		def unpack(self, str):		values = struct.unpack(self.__def__, str[:self.__size__])		i = 0		for name in self.__attrs__:			self.__values__[name] = values[i]			i += 1				return self		def pack(self):		values = [self.__values__[name] for name in self.__attrs__]		return struct.pack(self.__def__, *values)if __name__=='__main__':	class TestStruct(Struct):		def __init__(self):			Struct.__init__(self)						self.foo, self.bar = Struct.uint32, Struct.float						self.__cook__()		test = TestStruct()	test.unpack('\xEF\xBE\xAD\xDE\x00\x00\x80\x3F')	assert test.foo == 0xDEADBEEF	assert test.bar == 1.0		test.foo = 0xCAFEBABE	test.bar = 0.0	assert test.pack() == '\xBE\xBA\xFE\xCA\0\0\0\0'