This question is not directly related to zope, but I was told on comp.lang.python that this would be a better place to ask. The question is about the ExtensionClass package that now seems to be maintained as part of zope. I guess the problem might be encountered by some people writing zope packages, so it is sort of zope related :) I am looking at converting my pygtk wrapper for GTK+ over to using ExtensionClass (because it will reduce the amount of code needed, and make it easier to autogenerate the wrapper, among other reasons). This would involve creating a fairly deep heirachy of classes defined in C. While looking through the ExtensionClass documentation, there were examples of creating ExtensionClasses and subclassing extension classes from python, but no examples of subclassing from C. Is this actually possible to do with ExtensionClass? I noticed it is possible to create a PyMethodChain for each class, which would allow inheritance of methods, but does not handle `instance of' type relationships, which I need to do some type checking. I hope someone knows the answer to this. Thanks, James Henstridge. -- Email: james@daa.com.au WWW: http://www.daa.com.au/~james/