def ATypes(typeName, typeArgs):
    if type(typeArgs) == type(""):typeArgs = (typeArgs,)
    def creator(self, *args, **kwargs):
        i = 0
        for arg in typeArgs:
            if kwargs.has_key(arg):
                self.__dict__[arg] = kwargs[arg]
                del kwargs[arg]
            else:
                self.__dict__[arg] = args[i]
                i += 1
    globals()[typeName] = type(typeName, (), {'__init__': creator})

#Теперь тестим: 
ATypes('List', ('head', 'Tail'))
ATypes('Tail', 'List') 
s = List(1, List(2, None)) 
if isinstance(s.Tail, List):
    print s.Tail.head


ATypes('BTree', ('LH', 'RH', 'data'))
ATypes('LH', 'BTree')
ATypes('RH', 'BTree') 
MyTree = BTree(None, BTree(None, None, 2), 1)

if isinstance(MyTree , BTree) and isinstance(MyTree.RH , BTree):
    print MyTree.RH.data