Techniques to extend code without modifying it? (besides modules and decorators)

[Christian Seberino]

Paul

Thanks!  I'm glad there is theory about my concern.  I knew
I wasn't the only one with that question.

cs


> > https://en.wikipedia.org/wiki/Open%E2%80%93closed_principle
> 
> Also:
> 
> https://en.wikipedia.org/wiki/Expression_problem