Elliot Gorokhovsky added the comment: Your code changes __class__, not type, which would remain equal to "instance". (my understanding, could be wrong). The docs say the following:
https://docs.python.org/3.7/reference/datamodel.html > Like its identity, an object’s type is also unchangeable. [1] > > [1] It is possible in some cases to change an object’s type, under certain controlled conditions. > It generally isn’t a good idea though, since it can lead to some very strange behavior if it is > handled incorrectly. So I think it's safe to assume that type doesn't change; if you change type, you get undefined ("very strange") behavior. Based on the comment in the footnote, other code clearly assumes that type doesn't change, so I don't see why list.sort() should be any different. On Fri, Mar 10, 2017 at 5:08 PM ppperry <rep...@bugs.python.org> wrote: > > ppperry added the comment: > > Does this work with wacky code like this? > @functools.total_ordering > class ClassAssignmentCanBreakChecks(): > def __init__(self, i): > self._i = i > def __lt__ (self, other): > last.__class__ = OrdinaryOldInteger > return self._i < (other._i if hasattr(other, '_i') > else other) > @functools.total_ordering > class OrdinaryOldInteger: > def __init__(self, i): > self._i = i > def __lt__(self, other): > return self._i < (other._i if hasattr(other, '_i') > else other) > lst = [ClassAssignmentCanBreakChecks(i) for i in range(10)] > random.shuffle(lst) > last = lst[-1] > lst.sort() > It looks like it will initially say that all are the same type, and > attempt that optimization, which will probably lead to unexpected results > as that condition is no longer true after the first compare. > > ---------- > nosy: +ppperry > > _______________________________________ > Python tracker <rep...@bugs.python.org> > <http://bugs.python.org/issue28685> > _______________________________________ > ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue28685> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
