Re: Short-circuit Logic

Path	csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!eweka.nl!lightspeed.eweka.nl!194.109.133.81.MISMATCH!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path	<ian.g.kelly@gmail.com>
X-Original-To	python-list@python.org
Delivered-To	python-list@mail.python.org
X-Spam-Status	OK 0.025
X-Spam-Evidence	'H': 0.95; 'S': 0.00; 'parser': 0.07; '0.1': 0.09; 'integers': 0.09; 'wrong,': 0.09; "wouldn't": 0.14; '1):': 0.16; 'digits.': 0.16; 'unnecessary.': 0.16; 'wrote:': 0.18; 'thu,': 0.19; '>>>': 0.22; 'case.': 0.24; 'either.': 0.24; 'propose': 0.24; 'this:': 0.26; 'second': 0.26; 'pass': 0.26; 'least': 0.26; 'certain': 0.27; 'header:In-Reply-To:1': 0.27; 'chris': 0.29; 'message-id:@mail.gmail.com': 0.30; "i'm": 0.30; "d'aprano": 0.31; 'steven': 0.31; 'received:209.85': 0.35; 'equal': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'scheme': 0.36; 'received:209': 0.37; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'expect': 0.39; 'to:addr:python.org': 0.39; 'how': 0.40; 'ensure': 0.60; '30,': 0.65; 'world': 0.66; 'actually,': 0.84; 'this!': 0.93; '2013': 0.98
DKIM-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=i/wSWZSM8sPW9uRnDa2KCvfs6Mr2/jkH/ZhE/Hz1U08=; b=wFkwri05UpZP9aH6Y6jo4WXw0SnvquAzOa6LMpyRx/ZWKKt0RYp5gihBbusv1uvrfl V7AMj3yMGbmFAhxH3JtvpnPUk7EIKMuJl9LZfUqng0Bil4fRsQXwOnlamyWvT5UvuZgx u+hTDWHXjBO+13FYzt+azPNtJ/CFtjK2VUQ8YObULpWWL41I4DiQVcD4Ojc0wnMv56qs gFU0Z4vgfBUzHWPxqjJ9ubcsBjkiY7bXO8vZPfS5V4sKbpN8A9KSaNNmfZwqodCxDPTl d0qSmjAKXd+NIlq+Cm0Vo7NyhpUY9xP8+o9gpIkbs2yha+Ukho0dVxMURnoJTP6hTrDM ny0A==
X-Received	by 10.68.42.134 with SMTP id o6mr9524924pbl.149.1369943423799; Thu, 30 May 2013 12:50:23 -0700 (PDT)
MIME-Version	1.0
In-Reply-To	<b0pnn1F6r6uU1@mid.individual.net>
References	<5f101d70-e51f-4531-9153-c92ee2486fd9@googlegroups.com> <51a1fc7b$0$30002$c3e8da3$5496439d@news.astraweb.com> <2abf4e9c-8c3b-4e2f-80c9-50c1f1d75c9d@googlegroups.com> <51a4b5a1$0$29966$c3e8da3$5496439d@news.astraweb.com> <04b90c02-833a-4bad-88ad-ab71178b8f79@googlegroups.com> <51a6df59$0$11118$c3e8da3@news.astraweb.com> <mailman.2395.1369891346.3114.python-list@python.org> <b0pnn1F6r6uU1@mid.individual.net>
From	Ian Kelly <ian.g.kelly@gmail.com>
Date	Thu, 30 May 2013 13:49:43 -0600
Subject	Re: Short-circuit Logic
To	Python <python-list@python.org>
Content-Type	text/plain; charset=ISO-8859-1
X-BeenThere	python-list@python.org
X-Mailman-Version	2.1.15
Precedence	list
List-Id	General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe	<http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive	<http://mail.python.org/pipermail/python-list/>
List-Post	<mailto:python-list@python.org>
List-Help	<mailto:python-list-request@python.org?subject=help>
List-Subscribe	<http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups	comp.lang.python
Message-ID	<mailman.2449.1369943426.3114.python-list@python.org> (permalink)
Lines	29
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1369943426 news.xs4all.nl 15932 [2001:888:2000:d::a6]:60798
X-Complaints-To	abuse@xs4all.nl
Xref	csiph.com comp.lang.python:46540

Show key headers only | View raw

On Thu, May 30, 2013 at 1:30 PM, Neil Cerutti <neilc@norwich.edu> wrote:
> On 2013-05-30, Chris Angelico <rosuav@gmail.com> wrote:
>> On Thu, May 30, 2013 at 3:10 PM, Steven D'Aprano
>><steve+comp.lang.python@pearwood.info> wrote:
>>> # Wrong, don't do this!
>>> x = 0.1
>>> while x != 17.3:
>>>     print(x)
>>>     x += 0.1
>>
>> Actually, I wouldn't do that with integers either.
>
> I propose borrowing the concept of significant digits from the
> world of Physics.
>
> The above has at least three significant digits. With that scheme
> x would approximately equal 17.3 when 17.25 <= x < 17.35.
>
> But I don't see immediately how to calculate 17.25 and 17.35 from
> 17.3, 00.1 and 3 significant digits.

How about this:

while round(x, 1) != round(17.3, 1):
    pass

The second round call may be unnecessary.  I would expect the parser
to ensure that round(17.3, 1) == 17.3, but I'm not certain that is the
case.

Thread

Short-circuit Logic Ahmed Abdulshafy <abdulshafy@gmail.com> - 2013-05-26 04:11 -0700
  Re: Short-circuit Logic Roy Smith <roy@panix.com> - 2013-05-26 07:38 -0400
  Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-26 12:13 +0000
    Re: Short-circuit Logic Ahmed Abdulshafy <abdulshafy@gmail.com> - 2013-05-27 13:11 -0700
      Re: Short-circuit Logic Nobody <nobody@nowhere.com> - 2013-05-28 01:10 +0100
        Re: Short-circuit Logic Ahmed Abdulshafy <abdulshafy@gmail.com> - 2013-05-28 01:39 -0700
          RE: Short-circuit Logic Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-05-28 12:32 +0300
          Re: Short-circuit Logic Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-05-28 12:45 +0100
          Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-28 13:51 +0000
            Re: Short-circuit Logic Grant Edwards <invalid@invalid.invalid> - 2013-05-28 15:14 +0000
              Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-28 15:55 +0000
      Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-28 13:48 +0000
        Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-29 00:01 +1000
        Re: Short-circuit Logic Ahmed Abdulshafy <abdulshafy@gmail.com> - 2013-05-29 07:27 -0700
          Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-30 00:32 +1000
          Re: Short-circuit Logic rusi <rustompmody@gmail.com> - 2013-05-29 07:33 -0700
            Re: Short-circuit Logic Ian Kelly <ian.g.kelly@gmail.com> - 2013-05-29 10:50 -0600
              Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 02:28 +0000
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-30 13:45 +1000
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 05:42 +0000
                Re: Short-circuit Logic Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-05-30 10:22 +0300
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 08:29 +0000
                Re: Short-circuit Logic Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-05-30 12:07 +0300
                Re: Short-circuit Logic Nobody <nobody@nowhere.com> - 2013-05-30 23:55 +0100
                Re: Short-circuit Logic Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-30 19:31 -0400
                Re: Short-circuit Logic Stefan Drees <stefan@drees.name> - 2013-05-31 17:34 +0200
                Re: Short-circuit Logic Roy Smith <roy@panix.com> - 2013-05-30 08:48 -0400
                Re: Short-circuit Logic Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-30 19:38 -0400
                Re: Short-circuit Logic Nobody <nobody@nowhere.com> - 2013-05-31 02:10 +0100
                Re: Short-circuit Logic Roy Smith <roy@panix.com> - 2013-05-30 21:21 -0400
                Re: Short-circuit Logic Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-30 21:57 -0400
                Re: Short-circuit Logic Michael Torrie <torriem@gmail.com> - 2013-05-30 21:33 -0600
                RE: Short-circuit Logic Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-05-31 03:03 +0300
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-30 18:29 +1000
                RE: Short-circuit Logic Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-05-31 00:03 +0300
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-31 05:13 +0000
                RE: Short-circuit Logic Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-05-31 09:42 +0300
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-31 08:11 +0000
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-31 17:09 +1000
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-31 08:45 +0000
                Re: Short-circuit Logic Roy Smith <roy@panix.com> - 2013-05-31 09:20 -0400
                RE: Short-circuit Logic Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-06-01 10:23 +0300
                Re: Short-circuit Logic 88888 Dihedral <dihedral88888@gmail.com> - 2013-05-30 20:11 -0700
            Re: Short-circuit Logic Dave Angel <davea@davea.name> - 2013-05-29 20:23 -0400
              Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 05:20 +0000
          Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 05:10 +0000
            Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-30 15:22 +1000
              Re: Short-circuit Logic Roy Smith <roy@panix.com> - 2013-05-30 08:40 -0400
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-30 22:58 +1000
                Re: Short-circuit Logic rusi <rustompmody@gmail.com> - 2013-05-30 09:58 -0700
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-31 03:23 +1000
                Re: Short-circuit Logic Rick Johnson <rantingrickjohnson@gmail.com> - 2013-05-30 17:13 -0700
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-31 12:29 +1000
                Re: Short-circuit Logic Ethan Furman <ethan@stoneleaf.us> - 2013-05-30 08:02 -0700
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-31 01:56 +1000
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 16:40 +0000
                Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-30 19:22 +0000
                Re: Short-circuit Logic Chris Angelico <rosuav@gmail.com> - 2013-05-31 07:46 +1000
                Re: Short-circuit Logic Ethan Furman <ethan@stoneleaf.us> - 2013-05-30 09:30 -0700
              Re: Short-circuit Logic Neil Cerutti <neilc@norwich.edu> - 2013-05-30 19:30 +0000
                Re: Short-circuit Logic Ian Kelly <ian.g.kelly@gmail.com> - 2013-05-30 13:49 -0600
  Re: Short-circuit Logic Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-26 16:19 -0400
    Re: Short-circuit Logic Roy Smith <roy@panix.com> - 2013-05-26 16:22 -0400
      Re: Short-circuit Logic Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-26 17:28 -0400
      Re: Short-circuit Logic Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-27 00:40 +0000
        Re: Short-circuit Logic Cameron Simpson <cs@zip.com.au> - 2013-05-27 11:57 +1000
        Re: Short-circuit Logic rusi <rustompmody@gmail.com> - 2013-05-26 21:44 -0700
        Re: Short-circuit Logic Vito De Tullio <vito.detullio@gmail.com> - 2013-05-27 06:59 +0200
  Re: Short-circuit Logic Nobody <nobody@nowhere.com> - 2013-05-27 18:52 +0100
  Re: Short-circuit Logic Ahmed Abdulshafy <abdulshafy@gmail.com> - 2013-05-27 13:08 -0700
    Re: Short-circuit Logic Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-27 21:36 -0400

csiph-web