Re: Comparisons and sorting of a numeric class....

From	Gregory Ewing <greg.ewing@canterbury.ac.nz>
Newsgroups	comp.lang.python
Subject	Re: Comparisons and sorting of a numeric class....
Date	2015-01-16 22:23 +1300
Message-ID	<chs3kpFgp3aU1@mid.individual.net> (permalink)
References	(11 earlier) <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com> <54B5B486.7080406@r3dsolutions.com> <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com> <54B72D32.3090209@r3dsolutions.com> <mailman.17739.1421299637.18130.python-list@python.org>

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Ian Kelly wrote:
> Wait, are you actually asking why bool is a doubleton? If nobody has
> answered that, I think probably nobody understood you were asking it,
> because it shouldn't need to be explained.

What does perhaps need explaining is why Python goes
out of its way to *enforce* the doubleton-ness of bool.

I don't know all of Guido's reasoning on this, but part
of it is probably to do with implementation efficiencies.
There are several places in the CPython source where it's
assumed that, if an object is known to be of type bool,
then its truth or falseness can be determined with a
pointer comparison.

-- 
Greg

Thread

Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-12 17:59 -0800
  Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve@pearwood.info> - 2015-01-13 05:32 +0000
    Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-13 17:13 +1100
    Re: Comparisons and sorting of a numeric class.... Terry Reedy <tjreedy@udel.edu> - 2015-01-13 05:49 -0500
      Re: Comparisons and sorting of a numeric class.... Marko Rauhamaa <marko@pacujo.net> - 2015-01-13 13:00 +0200
        Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-13 22:20 +1100
        Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-13 11:56 -0700
        Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-14 06:02 +1100
    Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-13 21:56 +1100
    Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-13 16:12 -0800
    Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-14 01:31 -0700
    Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-14 22:26 -0700
      Re: Comparisons and sorting of a numeric class.... Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-16 22:23 +1300
    Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-14 23:23 -0800
      Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve@pearwood.info> - 2015-01-15 08:41 +0000
        Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-15 17:45 -0800
          Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-16 18:33 +1100
          Re: Comparisons and sorting of a numeric class.... Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-17 00:07 +1300
          Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-16 03:22 -0800
          Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-17 23:27 +1100
        Re: Comparisons and sorting of a numeric class.... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-01-16 02:27 +0000
        Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-15 22:01 -0700
        Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-16 17:58 +1100
      Re: Comparisons and sorting of a numeric class.... Rob Gaddi <rgaddi@technologyhighland.invalid> - 2015-01-15 09:54 -0800
        Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-26 15:47 -0800
        Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-26 18:50 -0700
    Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-15 10:05 -0700
    Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-23 03:46 -0800
      Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 07:31 -0800
        Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-23 09:50 -0700
          Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 09:03 -0800
            Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-24 04:23 +1100
              Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 09:29 -0800
            Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-23 11:04 -0700
              Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 19:13 -0800
              Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 19:21 -0800
            Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-24 16:01 +1100
              Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-24 16:43 +1100
          Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 09:22 -0800
            Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-24 04:37 +1100
              Re: Comparisons and sorting of a numeric class.... Rustom Mody <rustompmody@gmail.com> - 2015-01-23 09:45 -0800
                Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-24 05:03 +1100
                Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-23 11:13 -0700
      Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-24 19:27 +1100
    Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-23 22:58 +1100
    Re: Comparisons and sorting of a numeric class.... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-01-23 12:07 +0000
    Re: Comparisons and sorting of a numeric class.... Terry Reedy <tjreedy@udel.edu> - 2015-01-23 11:17 -0500
    Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-23 11:00 -0700

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