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Re: code review

Newsgroups comp.lang.python
From Albert van der Horst <albert@spenarnc.xs4all.nl>
Subject Re: code review
Date 2012-07-13 12:30 +0000
Message-ID <m73mrb.cke@spenarnc.xs4all.nl> (permalink)
Organization Dutch Forth Workshop
References <mailman.1623.1340939177.4697.python-list@python.org> <mailman.1659.1341089444.4697.python-list@python.org> <4ff0f8e0$0$29988$c3e8da3$5496439d@news.astraweb.com>

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In article <4ff0f8e0$0$29988$c3e8da3$5496439d@news.astraweb.com>,
Steven D'Aprano  <steve+comp.lang.python@pearwood.info> wrote:
>On Sun, 01 Jul 2012 05:55:24 -0400, Terry Reedy wrote:
>
>> On 7/1/2012 2:54 AM, Steven D'Aprano wrote:
>>
>>> So no, Python has always included chained comparisons, and yes, it is
>>> shameful that a language would force you to unlearn standard notation
>>> in favour of a foolish consistency with other operators. Comparisons
>>> aren't special because they return bools. They are special because of
>>> the way they are used.
>>>
>>> C treats comparison operators as if they were arithmetic operators, and
>>> so the behaviour of a chained comparison is the same as the behaviour
>>> as a sequence of arithmetic operators: a foolish consistency. Python
>>> treats comparison operators as comparison operators, and gives them
>>> behaviour appropriate to comparisons.
>>
>> I considered this a great feature of Python when I first learned it.
>> Reading about how rare it is among programming languages to treat
>> comparisons in the standard way in mathematics reinforces that.
>
>Apart from Python, Mathematica, Perl 6, CoffeeScript, Cobra and Clay give
>chained comparisons the standard meaning. It is, or was, a feature
>request for Boo, but I can't tell whether it has been implemented or not.

Algol 68 does not. It has promoted operator symbols to first
class citizens. In that context chained comparison operators
cannot be made to work.
Both Mathematica and Perl are ad-hoc-ish languages. I would
hate Python go that way.

From now on, for each operator I would have to remember wether it
is a supposedly comparison operator or not.

Comparison operations on booleans make sense.
I remember a FORTRAN compiler complaining about me
comparing LOGICALS. The lack of abstraction!

>
>
>C-like semantics are next to useless, except perhaps for obfuscation:
>
>http://stackoverflow.com/questions/4089284/why-does-0-5-3-return-true/
>
>And surprising:
>
>http://answers.yahoo.com/question/index?qid=20090923172909AA4O9Hx
>
>C-like semantics are a clear case of purity of implementation overruling
>functional usefulness.

The worst of is, of course, = for assignment instead of := .
This is a convention that Python follows, to my dismay.

>
>--
>Steven

Groetjes Albert

--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

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code review "Littlefield, Tyler" <tyler@tysdomain.com> - 2012-06-28 20:57 -0600
  Re: code review alex23 <wuwei23@gmail.com> - 2012-06-28 20:58 -0700
    Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-06-29 07:31 +0000
      Re: code review Chris Angelico <rosuav@gmail.com> - 2012-06-29 17:42 +1000
      Re: code review "Littlefield, Tyler" <tyler@tysdomain.com> - 2012-06-29 09:03 -0600
        Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-29 19:41 +0000
          Re: code review MRAB <python@mrabarnett.plus.com> - 2012-06-29 21:09 +0100
          Re: code review "Martin P. Hellwig" <martin.hellwig@gmail.com> - 2012-06-29 13:27 -0700
            Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-29 20:43 +0000
              Re: code review Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-06-29 19:02 -0400
              Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-06-29 23:02 -0400
          Re: code review "Littlefield, Tyler" <tyler@tysdomain.com> - 2012-06-29 14:49 -0600
            Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-30 09:31 +0000
              Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-30 09:36 +0000
          Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-06-30 02:28 +0000
            Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-30 09:22 +0000
          Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-06-29 23:00 -0400
        Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-30 10:04 +0000
          Re: code review Peter Otten <__peter__@web.de> - 2012-06-30 12:29 +0200
            Re: code review Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-06-30 20:39 +0200
              Re: code review Thomas Jollans <t@jollybox.de> - 2012-06-30 21:38 +0200
                Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-30 20:30 +0000
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-06-30 22:50 +0200
                Re: code review Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2012-06-30 23:07 +0200
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-06-30 23:35 +0200
                Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-06-30 17:47 -0400
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-01 00:05 +0200
                Re: code review Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2012-07-01 01:03 +0200
                Re: code review Ben Finney <ben+python@benfinney.id.au> - 2012-07-01 10:08 +1000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 10:37 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-01 03:23 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 13:48 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-01 06:54 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 16:59 +1000
                Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-07-01 05:55 -0400
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-02 01:26 +0000
                Re: code review Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-13 12:30 +0000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-13 15:04 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-14 01:36 +1000
                Re: code review rusi <rustompmody@gmail.com> - 2012-07-13 09:24 -0700
                Re: code review Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-13 16:39 -0400
                Re: code review Duncan Booth <duncan.booth@invalid.invalid> - 2012-07-16 10:43 +0000
                Re: code review Ben Finney <ben+python@benfinney.id.au> - 2012-07-16 21:34 +1000
                Re: code review Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-17 10:54 +0000
                Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-07-13 19:09 -0400
                Re: code review Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-14 03:26 -0600
                Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-07-14 16:42 -0400
                Re: code review rusi <rustompmody@gmail.com> - 2012-06-30 21:07 -0700
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 14:20 +1000
                Re: code review Ben Finney <ben+python@benfinney.id.au> - 2012-07-01 17:28 +1000
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-01 09:46 +0200
                Re: code review HoneyMonster <nobody@someplace.invalid> - 2012-07-01 20:53 +0000
                Re: code review Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-01 05:18 -0400
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-02 00:41 +0000
                Re: code review Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-01 21:40 -0400
                Re: code review Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-01 13:41 -0400
                Re: code review John O'Hagan <research@johnohagan.com> - 2012-07-02 14:43 +1000
                Re: Re: code review Evan Driscoll <driscoll@cs.wisc.edu> - 2012-06-30 23:45 -0500
                Re: Re: code review Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-07-01 08:57 +0200
                Re: code review Alister <alister.ware@ntlworld.com> - 2012-07-01 09:54 +0000
                Re: Re: code review Evan Driscoll <driscoll@cs.wisc.edu> - 2012-07-01 10:48 -0500
                Re: Re: code review lars van gemerden <lars@rational-it.com> - 2012-07-06 04:22 -0700
                Re: Re: code review lars van gemerden <lars@rational-it.com> - 2012-07-06 04:22 -0700
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-06 13:58 +0000
                Re: code review Roy Smith <roy@panix.com> - 2012-07-13 08:32 -0700
                Re: code review Evan Driscoll <driscoll@cs.wisc.edu> - 2012-06-30 23:57 -0500
                Re: code review Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-07-01 09:04 +0200
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-01 02:06 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 12:20 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-01 04:17 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 14:23 +1000
                Re: code review Steven D'Aprano <steve+usenet@pearwood.info> - 2012-07-01 06:27 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 16:33 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-02 01:28 +0000
                Re: code review Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-01 21:50 -0400
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-02 07:29 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-02 12:04 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-02 08:11 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-02 18:20 +1000
                Re: code review Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-02 08:57 -0700
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-03 02:42 +1000
                Re: code review Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-02 11:22 -0700
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-02 21:06 +0200
                Re: code review Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-02 12:35 -0700
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-03 07:57 +1000
                Re: code review Neil Cerutti <neilc@norwich.edu> - 2012-07-03 12:19 +0000
                Re: code review Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-02 01:20 -0400
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-02 16:41 +0200
                Re: code review Terry Reedy <tjreedy@udel.edu> - 2012-07-02 11:33 -0400
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-01 09:35 +0200
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-02 00:43 +0000
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-02 16:26 +0200
                Re: code review Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-02 08:16 -0700
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-03 02:55 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-03 00:57 +0000
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-03 11:22 +1000
                Re: code review John O'Hagan <research@johnohagan.com> - 2012-07-03 12:25 +1000
                Re: code review Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-03 04:11 +0000
                Re: code review Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-03 02:09 -0400
                Re: code review Roy Smith <roy@panix.com> - 2012-07-03 08:33 -0400
                Re: code review Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-03 16:53 +0100
                Re: code review Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-03 17:32 -0400
                Re: code review rusi <rustompmody@gmail.com> - 2012-07-02 22:10 -0700
                Re: code review Ben Finney <ben+python@benfinney.id.au> - 2012-07-03 15:46 +1000
                Re: code review John O'Hagan <research@johnohagan.com> - 2012-07-04 00:59 +1000
                Re: code review Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-03 16:50 +0100
                Re: code review Paul Rudin <paul.nospam@rudin.co.uk> - 2012-07-04 10:29 +0100
                Re: code review Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-04 17:25 +0100
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-04 01:53 +1000
                Re: code review Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-03 17:05 +0100
                Re: code review Dave Angel <d@davea.name> - 2012-07-03 16:13 -0400
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-04 07:54 +1000
                Re: code review Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-04 09:28 +0100
                Re: code review rusi <rustompmody@gmail.com> - 2012-06-30 19:37 -0700
                Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-01 09:25 +1000
                Re: code review Thomas Jollans <t@jollybox.de> - 2012-07-01 01:50 +0200
                Re: code review "Martin P. Hellwig" <martin.hellwig@gmail.com> - 2012-06-30 14:48 -0700
                Re: code review Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-02 13:16 -0600
            Re: code review Alister <alister.ware@ntlworld.com> - 2012-06-30 20:25 +0000
          Re: code review Kushal Kumaran <kushal.kumaran+python@gmail.com> - 2012-07-03 23:23 +0530
            Re: code review John Gordon <gordon@panix.com> - 2012-07-03 18:18 +0000
              Re: code review Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-03 12:27 -0600
              Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-04 07:51 +1000
          Re: code review Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-03 12:19 -0600
          Re: code review kushal.kumaran+python@gmail.com - 2012-07-04 08:27 +0530
          Re: code review Chris Angelico <rosuav@gmail.com> - 2012-07-04 13:53 +1000
          Re: code review Simon Cropper <simoncropper@fossworkflowguides.com> - 2012-07-04 14:55 +1000
          Re: code review "Littlefield, Tyler" <tyler@tysdomain.com> - 2012-07-03 23:39 -0600
            Re: code review alex23 <wuwei23@gmail.com> - 2012-07-03 23:17 -0700
              Re: code review rusi <rustompmody@gmail.com> - 2012-07-04 00:05 -0700
          Apology for OT posts (was: code review) John O'Hagan <research@johnohagan.com> - 2012-07-06 12:06 +1000
          Re: Apology for OT posts Simon Cropper <simoncropper@fossworkflowguides.com> - 2012-07-06 15:30 +1000
          Re: Apology for OT posts Chris Angelico <rosuav@gmail.com> - 2012-07-06 17:45 +1000
          Re: Apology for OT posts Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-06 10:37 +0100

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