[Python-Dev] Re: redefining is
Casey Duncan
casey at zope.com
Thu Mar 18 14:38:03 EST 2004
On Thu, 18 Mar 2004 10:51:02 -0800
Guido van Rossum <guido at python.org> wrote:
> > Indeed. Of course, object() is mutable, so there is no proposal to
> > change the meaning of this program. What I'm concerned about is
> > someone trying to do the same thing this way:
> >
> > missing = 'missing'
> >
> > if d.get('somekey', missing) is 'missing':
> > # it ain't there
> >
> > This code contains a bug, but on an implementation that interns
> > strings that happen to look like identifiers, no test will detect
> > the bug.
>
> I'm ready to pronounce. The code is buggy. There are good reasons to
> keep 'is' the way it always was. The definition of 'is' ain't gonna
> change. So be it.
So then: is is as is was ;^)
-Casey
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