[pvg]

Right. It doesn't happen by rooting around objects looking for methods by name. That's usually a sign of some misdesign that's making you re-invent the polymorphic mechanisms of the language yourself. True both in Java and Python.

[ighost]

I agree that polymorphism is the "right way" if there's already a class hierarchy established.

If the superclass-subclass relationships aren't in place for you (worse yet, they're not set up how you want them to be set up), this hack accomplishes a similar effect with no refactoring.