Thought I'd share an update on my efforts to solve what I had termed a "method loading" issue in trying to achieve the scripting interface I had envisioned for PyGeo. The discussion is in the August edu-sig archive. I had written -

And in doing some real error catching and reporting on arguments, I would expect isinstance will come into play, and in doing it, it should not be very much additional burden to do it in such a way so that at least I can make argument order irrelevant.

After that I guess I need to see where I am, and then take the more complex issues of this kind on a case by case basis - there probably is no one-size answer for all cases.

Turns out "issubclass", rather than "issinstance", was the key to accomplishing what I wanted. And I was able to accomplish everything I had hoped - methods called based on passed arguments (order insensitive), error reporting of invalid argument sets,etc. - with a ten line function. The function is currently, BTW, ugly and broken - but basically funtional. I will get it refined in due course. Using this, and the occasional string qualifier, there are in the end going to be maybe 15 "argument smart" classes with which the user interacts, rather the 40 to 50 there had been. Another BTW: I also wanted to be lenient in terms of the passing of string qualifiers. "CircumCenter", "Cirumcenter", "Circum_Center", "Circum_center" all acceptable.Was simple to implement. So whether I have made the right choices for my Scripting Interfacte remains to be seen. But in the end Python posed no limitation on allowing me to implement exactly what I envisioned, in all essential respects. Also satisfying that I have been able to implement a serviceable (though not perfect) Observer pattern in a few lines of Python. Essentially as classes are instantiated, its arguments, and recursively, the arguments to its argments, are inspected. The class instance is registered to any of these arguments which are accessible for manipulation to the user through the GUI. The result, of course, is that when a point (for example) is interactively picked and moved, only the class instances registered with it need to be updated. Significant performance benefit - depending on the complexity of the construction. In short, having much fun. Art