On 9/16/07, Mathieu Fenniak <[EMAIL PROTECTED]> wrote: > On 16-Sep-07, at 7:56 PM, Guido van Rossum wrote: > > So suppose my answer was "no, bytes won't be subclassable". How much > > would you really lose by having to wrap a separate object around a > > bytes object, rather than being able to subclass? How much extra code > > do you think you would have to write? > > > > Another way to look at it-- how much of the bytes type's API do your > > objects really have to support? > > Most often, I'd be concatenating and comparing with other bytes > objects, iterating through the byte array, and passing the byte array > into methods like stream.write. Iterating and comparing could be > dealt with by some code in the containing class; for other needs, I > would sprinkle ".data" property accesses throughout the code to > access the bytes instance.
OK, so it sounds like at least you are treating it as a bytes array. > I'm not too concerned about the programming I'd have to do, even > though the end result wouldn't really be what I'd like to have. It's > not the end of the world, it's just not ideal. > > I do think that subclassing bytes would probably be a request a few > people would have, especially when porting Python 2 code that > subclasses str. Well, due to bytes' mutability, they'll be in for a ton of surprises. > It seems especially unusual that bytes can't be > subclassed, when builtin types like str, list, dict, and set can be. Maybe I should apologize for pushing back so hard, but in my experience most people who subclass a built-in type do it because they can, not because they should -- the lamented "path" module being a prime example in my view. I'm still not convinced of the usefulness in your case -- what would you lose if you just passed a bytes instance around instead of an instance of the subclass you'd like to have? -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
