Has comparison of instancemethods changed between python 2.5 and 2.4?

[Carl Banks]

Frank Niessink wrote:
> Ziga Seilnacht:
> > This method was changed in Python 2.5. Previously, two instancemethods
> > compared equal if their im_self attributes were *identical* and their
> > im_func attributes were equal. Now, they compare equal if their im_self
> > attributes are *equal* and their im_func attributes are equal.
>
> Thanks Ziga, that explains very clearly why I get the behavior I see.
>
> > If you think this is a bug, you should report it to the bugtracker:
> > http://sourceforge.net/bugs/?group_id=5470
>
> Well, from where I am it sure feels like a bug in python, so I've
> submitted a bug report:
> http://sourceforge.net/tracker/index.php?func=detail&aid=1617161&group_id=5470&atid=105470

In the interests of practicality beating purity, I would agree that the
2.4 behavior is better.  (I don't know if it would be classified as a
bug; the behavior of methods under == isn't documented AFAICT.)
There's no question that the 2.5 behavior is purer, but I can't imagine
a single use case for it.

In the meanwhile, you could work around it by using this function
instead:

def same_method(a,b):
    return a.im_class is b.im_class and a.im_func is b.im_func and
a.im_self is b.im_self



Carl Banks