Mike Meyer wrote: > [EMAIL PROTECTED] writes: > > Mike Meyer wrote: > >> [EMAIL PROTECTED] writes: > >> > Well, in this case, would it be simple for the OP that if he wants to > >> > disallow this attaching additional things, just use __slot__. > >> That's *documented* as an implementation-dependent behavior. Using it > >> to get that effect is abuse of the feature, and may well quit working > >> in the future. > > It still won't affect what is working, so it is harmless side effect, > > if it ever changes in the future. > > If not allowing is required, then allowing is "not working", pretty > much by definition. > > > Abuse or not doesn't matter so long it fits the needs, IMO. > > I guess it doesn't matter to you whether or not your code works in the > future. It does to me. > For this particular case, I don't see it as a problem.
First it meets the need, works on 2.2, 2.3, 2.4. No one knows what would change in the future, beside the fact that I don't see it as implementation-dependent in the doc. Adding to the fact that things can/may be removed even it is fully documented, without this caveat emptor(like the famous reduce/map etc.). That is if I read the document when I was writing python codes in the early days and used reduce/map/filter/lambda, my code still breaks if in one day those are removed and I can't forsee that either. So why bother, unless it has some definitive schedule(like saying in 2.5, reduce won't be there or __slot__ behaviour will definitely change), then I would consider if the code I write now should avoid using it. And back to this case, I regard it as a no harm side effect, yes, it doesn't perform as expected(assume it really is changed in some unknown version in the future) that someone does hang something there, it doesn't hurt my expected usage of the class, as this is used to prevent unexpected usage. Quoting the frequently used term "Practicality beats purity". If I have a practical problem/needs now and it solves it, why not use it ? The zip(it,it) case is even worse than this __slot__ situation and I don't have much problem in using that either. It is not unusual in this industry that certain software only expects to be working with some combination of OS/Compiler version. -- http://mail.python.org/mailman/listinfo/python-list
