On Fri, 25 Nov 2005 20:50:41 -0500, Mike Meyer wrote: > Steven D'Aprano <[EMAIL PROTECTED]> writes: >> On Thu, 24 Nov 2005 11:44:16 -0500, Mike Meyer wrote: >>> In Python, I can even fix >>> it so *your* code uses my wrapped version: >>> >>> import Finney >>> class Addable(Finnney.Immutable): pass >>> Finney.Immutable = Addable >> >> Python's consenting adults philosophy allows the class designer some >> limited ability to force the class user to think about it before messing >> about with private variables. I think Ben's immutable class falls into >> that same category. > > If you read the whole thread, you'll see that I don't have a problem > with messing with private variables. It's disallowing the addition of > new variables that I found objectionable.
But you've just demonstrated that those who really want to shoot themselves in the foot, er, add new attributes (not variables, let's get the terminology right) can do so by sub-classing and rebinding. The fact that Ben's proposal would prevent you from adding attributes is precisely analogous to the name mangling that Python does: if you want to work around it, it is easy to do so, but you have to make a conscious effort to do so it. "Hmmm, the class designer didn't want me adding attributes to instances... maybe he had a good reason for that..." -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
