Bugs item #1617161, was opened at 2006-12-16 21:36 Message generated for change (Comment added) made by arigo You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1617161&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Interpreter Core Group: Python 2.5 Status: Open Resolution: None Priority: 5 Private: No Submitted By: Frank Niessink (fniessink) Assigned to: Armin Rigo (arigo) >Summary: Instance methods compare equal when their self's are equal Initial Comment: Python 2.5 was changed so that instance methods compare equal when their im_self attributes compare equal. Here's a link to that change: http://svn.python.org/view?rev=46739&view=rev This is a problem if we want to distinguish between methods of instances that compare equal, for example when methods can be registered as callbacks (see attached example). It seems unlogical to me that whether or not the instance methods of two different instances are equal or not depends on the equality of the instance. Thanks, Frank ---------------------------------------------------------------------- >Comment By: Armin Rigo (arigo) Date: 2006-12-17 12:19 Message: Logged In: YES user_id=4771 Originator: NO I see. Indeed, in the callback situation the 2.5 change is not very good. On the other hand, I have a (possibly more obscure) case where the new equality makes more sense. Note also that the change was meant to unify the behavior of built-in and user method objects; e.g. if you use callbacks as dict keys, then already in previous Python versions it was impossible to use say 'mylist.append' as a callback. Moreover, the hash of user methods was strangely based on the hash of the object itself already, which made dict key collisions likely. All in all I think that this part was an accident and never designed; I won't pronounce myself and suggest that python-dev should decide which of the two behaviors is realy "expected". ---------------------------------------------------------------------- Comment By: Martin v. Löwis (loewis) Date: 2006-12-16 23:07 Message: Logged In: YES user_id=21627 Originator: NO Armin, can you please comment? ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1617161&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
