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Groups > comp.lang.python > #86967
| From | Ben Finney <ben+python@benfinney.id.au> |
|---|---|
| Subject | Re: Is nan in (nan,) correct? |
| Date | 2015-03-06 10:39 +1100 |
| References | <mailman.67.1425594415.21433.python-list@python.org> <eb903edb-6400-4a61-8d79-e8a8535443e7@googlegroups.com> <mailman.70.1425597600.21433.python-list@python.org> <5cfab73a-ec0b-488b-8787-72e7640dc352@googlegroups.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.72.1425598789.21433.python-list@python.org> (permalink) |
sohcahtoa82@gmail.com writes:
> On Thursday, March 5, 2015 at 3:20:16 PM UTC-8, Ben Finney wrote:
> > It is fine to define such a type in Python, because 'is' does not
> > necessarily imply '=='.
>
> Do you have an example of where `a is b` but `a != b` in Python?
Maybe I misunderstand your question, but you've already been discussing
such an example. Here it is for clarity::
>>> nan = float("NaN")
>>> (nan is nan) == (nan == nan)
False
>>> nan is nan
True
>>> nan == nan
False
> `None == None` is True.
Right, the Python `None` is not the null I was describing. Python does
allow for a null with the semantics I described, because ‘is’ does not
imply ‘==’.
--
\ “We suffer primarily not from our vices or our weaknesses, but |
`\ from our illusions.” —Daniel J. Boorstin, historian, 1914–2004 |
_o__) |
Ben Finney
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Is nan in (nan,) correct? random832@fastmail.us - 2015-03-05 17:26 -0500
Re: Is nan in (nan,) correct? sohcahtoa82@gmail.com - 2015-03-05 15:11 -0800
Re: Is nan in (nan,) correct? Ben Finney <ben+python@benfinney.id.au> - 2015-03-06 10:20 +1100
Re: Is nan in (nan,) correct? sohcahtoa82@gmail.com - 2015-03-05 15:27 -0800
Re: Is nan in (nan,) correct? Ben Finney <ben+python@benfinney.id.au> - 2015-03-06 10:39 +1100
Re: Is nan in (nan,) correct? Chris Angelico <rosuav@gmail.com> - 2015-03-06 10:40 +1100
Re: Is nan in (nan,) correct? Chris Angelico <rosuav@gmail.com> - 2015-03-06 10:25 +1100
Re: Is nan in (nan,) correct? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-06 13:09 +1100
Re: Is nan in (nan,) correct? Ben Finney <ben+python@benfinney.id.au> - 2015-03-06 13:55 +1100
Re: Is nan in (nan,) correct? Ethan Furman <ethan@stoneleaf.us> - 2015-03-05 19:18 -0800
Re: Is nan in (nan,) correct? Ben Finney <ben+python@benfinney.id.au> - 2015-03-06 14:26 +1100
Re: Is nan in (nan,) correct? Ethan Furman <ethan@stoneleaf.us> - 2015-03-05 19:44 -0800
Re: Is nan in (nan,) correct? Chris Angelico <rosuav@gmail.com> - 2015-03-06 14:49 +1100
Re: Is nan in (nan,) correct? random832@fastmail.us - 2015-03-05 23:37 -0500
Re: Is nan in (nan,) correct? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-07 04:07 +1100
Re: Is nan in (nan,) correct? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-06 04:46 +0000
Re: Is nan in (nan,) correct? Rustom Mody <rustompmody@gmail.com> - 2015-03-06 01:50 -0800
Re: Is nan in (nan,) correct? Chris Angelico <rosuav@gmail.com> - 2015-03-06 21:01 +1100
Re: Is nan in (nan,) correct? Rustom Mody <rustompmody@gmail.com> - 2015-03-06 02:22 -0800
Re: Is nan in (nan,) correct? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-07 03:59 +1100
Re: Is nan in (nan,) correct? Rustom Mody <rustompmody@gmail.com> - 2015-03-06 10:04 -0800
Re: Is nan in (nan,) correct? Ethan Furman <ethan@stoneleaf.us> - 2015-03-06 10:16 -0800
Re: Is nan in (nan,) correct? Grant Edwards <invalid@invalid.invalid> - 2015-03-06 15:34 +0000
Re: Is nan in (nan,) correct? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-07 03:43 +1100
Re: Is nan in (nan,) correct? Rustom Mody <rustompmody@gmail.com> - 2015-03-06 09:04 -0800
Re: Is nan in (nan,) correct? Chris Angelico <rosuav@gmail.com> - 2015-03-07 04:16 +1100
Re: Is nan in (nan,) correct? Rustom Mody <rustompmody@gmail.com> - 2015-03-06 09:36 -0800
Re: Is nan in (nan,) correct? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-07 10:33 +1100
Re: Is nan in (nan,) correct? Rustom Mody <rustompmody@gmail.com> - 2015-03-06 18:37 -0800
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