While browsing through Zope and product Python source code, I often see a method being called on an object and want to find out what it's doing and look up the definition. Because Zope objects often have many superclasses, I end up scanning through many class definitions. (My most recent experience was finally finding the definition of this() in the Item class, and saying, oh yes, that's correct, it doesn't do anything :-) And, there's always a danger that I'll miss a definition in a subclass or a superclass that gets inherited first, and be looking at the wrong method definition for the particular object. Is there a way in the runtime or in the debugger, perhaps through the magic of Python reflection, to ask "when I call this method on this object, this is the class providing the definition?"