sorry, forget all I wrote: I should have read this more thoroughly, it explained it all http://www.cafepy.com/article/python_attributes_and_methods/python_attributes_and_methods.htm
<http://www.cafepy.com/article/python_attributes_and_methods/python_attributes_and_methods.html>Descriptors only works with type objects, not instance. and you can't write from an instance object to a class variable. You can only hide it. Also __slots__ works by creating descriptors in the class and preventing creation of any atrributes in the class instance, so everything is clear now Dave
-- http://mail.python.org/mailman/listinfo/python-list
