Message 222270 - Python tracker

Message222270

Author	andymaier
Recipients	andymaier, chris.jerdonek, cvrebert, docs@python, ezio.melotti, mark.dickinson, mikehoy, rhettinger, terry.reedy
Date	2014-07-04.08:08:11
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1404461291.9.0.407027483922.issue12067@psf.upfronthosting.co.za>
In-reply-to

Content
Terry, I'd like to comment on your statement: > 3. By default, == and /= compare identities. in msg148774. What experiment lead you to that conclusion? Here is one that contradicts it (using cpython 3.4.1): >>> i1 = 42 >>> f1 = 42.0 >>> i1 == f1 True >>> i1 is f1 False Is it possible, that your experiment got influenced by the optimization that attempts to reuse existing objects of immutable types? Like in this: >>> i1 = 42 >>> i2 = 40 + 2 >>> i1 == i2 True >>> i1 is i2 True Andy

Content

Terry,
I'd like to comment on your statement:
> 3. By default, == and /= compare identities.
in msg148774.

What experiment lead you to that conclusion?

Here is one that contradicts it (using cpython 3.4.1):

>>> i1 = 42
>>> f1 = 42.0
>>> i1 == f1
True
>>> i1 is f1
False

Is it possible, that your experiment got influenced by the optimization that attempts to reuse existing objects of immutable types?
Like in this:

>>> i1 = 42
>>> i2 = 40 + 2
>>> i1 == i2
True
>>> i1 is i2
True

Andy

History
Date	User	Action	Args
2014-07-04 08:08:11	andymaier	set	recipients: + andymaier, rhettinger, terry.reedy, mark.dickinson, ezio.melotti, cvrebert, chris.jerdonek, docs@python, mikehoy
2014-07-04 08:08:11	andymaier	set	messageid: <1404461291.9.0.407027483922.issue12067@psf.upfronthosting.co.za>
2014-07-04 08:08:11	andymaier	link	issue12067 messages
2014-07-04 08:08:11	andymaier	create