[Zope] ExtensionClass peculiarity (was: [Zope-PTK] Multiple Inheritance and the Portal Base classes.) (was: [Zope-PTK] Multiple Inheritance and the Portal Base classes.)

Steinar Rune Eriksen writes:

In other Python programs, calling Parent.__init__(self) works fine, but when running through Zope in this context

Error Type: TypeError Error Value: unbound method must be called with class instance 1st argument Have a look at the "ExtensionClass" documentation (-> zope.org).

ExtensionClass is not completely compatible with Python: if a class "C" inherits from an extension class "E" and from a normal Python class "P", then Python does not recognize "C" as a subclass from "P". The mentioned documentation tells you, that there is a method "InheritedAttribute" to work around this problem. Dieter