[ESR]
For different reasons, I'd like to be able to set a constant flag on a object instance. Simple semantics: if you try to assign to a member or method, it throws an exception.
Application? I have a large Python program that goes to a lot of effort to build elaborate context structures in core. It would be nice to know they can't be even inadvertently trashed without throwing an exception I can watch for.
Yes, this is a good thing. Easy to do on lists and dicts. Questions: - How to spell it? x.freeze()? x.readonly()? - Should this reversible? I.e. should there be an x.unfreeze()? - Should we support something like this for instances too? Sometimes it might be cool to be able to freeze changing attribute values... --Guido van Rossum (home page: http://www.python.org/~guido/)