[Tutor] creating a subclass from superclass without __init__

[Matt Gregory]

Is it possible to create a subclass of a superclass that doesn't have an 
__init__ and is only created through another class.  Here is an example 
of what isn't working:

class Spam(object):
     def __new__(cls, *args):
         return super(Spam, cls).__new__(cls, args)
     def __init__(self):
         raise AttributeError('Cannot create Spam')
     def test(self):
         print 'This is a Spam class'

class SpamMaker(object):
     def make_spam(self):
         return Spam.__new__(Spam)

class SubSpam(Spam):
     def __new__(cls, *args):
         return SpamMaker().make_spam()
     def test(self):
         print 'This is a SubSpam class'

b = SpamMaker().make_spam()
b.test()

c = SubSpam()
c.test()

prints

This is a Spam class
This is a Spam class

I know that I'm not creating the SubSpam instance correctly, but I have 
no idea how to do it.  It's probably something very obvious that I'm 
missing.  My real use case is using the Python bindings to GDAL and 
trying to create a subclass of gdal.Band which can't be instantiated 
directly.

thanks, matt