Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #96312

Re: Python handles globals badly.

Path csiph.com!news.swapon.de!feeder.erje.net!1.eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed7.news.xs4all.nl!nzpost1.xs4all.net!not-for-mail
Return-Path <rosuav@gmail.com>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.000
X-Spam-Evidence '*H*': 1.00; '*S*': 0.00; 'operator': 0.03; 'value,': 0.03; 'subject:Python': 0.05; 'assignment': 0.07; 'repeated': 0.07; 'cc:addr:python-list': 0.09; 'spelling': 0.09; 'python': 0.10; 'useful,': 0.13; 'thu,': 0.15; '"while': 0.16; 'boolean': 0.16; 'comma': 0.16; 'consciously': 0.16; 'expected,': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'operator.)': 0.16; 'value),': 0.16; 'wrote:': 0.16; "wouldn't": 0.16; '2015': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; 'prevent': 0.20; 'logical': 0.22; 'sep': 0.22; 'am,': 0.23; '(like': 0.23; 'ignored.': 0.23; 'thus': 0.24; 'written': 0.24; 'header:In-Reply-To:1': 0.24; 'sort': 0.25; "doesn't": 0.26; 'sense': 0.26; 'chris': 0.26; 'fri,': 0.27; 'message- id:@mail.gmail.com': 0.27; 'yield': 0.27; 'yields': 0.29; "i'm": 0.30; 'posts': 0.30; 'skip:_ 10': 0.32; 'statement': 0.32; 'useful': 0.33; 'previous': 0.34; 'received:google.com': 0.35; 'could': 0.35; 'returning': 0.35; 'something': 0.35; 'but': 0.36; '(and': 0.36; 'subject:: ': 0.37; 'two': 0.37; 'expect': 0.37; 'say': 0.37; 'doing': 0.38; 'why': 0.39; "didn't": 0.39; 'where': 0.40; 'some': 0.40; 'your': 0.60; 'places': 0.64; 'legal': 0.66; 'therefore': 0.67; 'chrisa': 0.84; 'to:none': 0.91; 'mistake': 0.91
DKIM-Signature v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=yPlaaLD+gB7FV4fB+/vG60N32x/6oz6EGO9Ozhbndaw=; b=v2EQ4suTqGT06J0bqcR/sERTrftPp+Gm1KFAgxFWHpWCquYD2ysuy6DL3cxkjS/53K BoLEjpZ+plVPpXMG843+JFsDjWk/CGkaryZdbHH2tcPbFVCtByLiuBAtALyFxR7B6w6B 9yAbT2anMPeQRNTw6es2G4uEpD0w36g/danRhdceO3jw99w33mMnFVub7WvkxoJUSnLB +wh0JjfOwiHzDxtTHlhxqkbsoyaGGkHFyy1L34MxPT9RIBLwvkNv6hW1VsFmpbd5/5DQ IDASSuqTT8GZ4IabXz66Uk/kriNJDerV0AKWroUR9hfbbx5bbLNStYfSNp2Qem7RmWm7 AhaA==
MIME-Version 1.0
X-Received by 10.50.98.7 with SMTP id ee7mr11462297igb.13.1441935340784; Thu, 10 Sep 2015 18:35:40 -0700 (PDT)
In-Reply-To <1441915664.3216384.380230649.5CF010BC@webmail.messagingengine.com>
References <c3363$547e74fe$5419aafe$24179@news.ziggo.nl> <86fa425b-d660-45ba-b0f7-3beebdec8e14@googlegroups.com> <CALwzid=sokeEcPA17yP=Npscg4VSJ6AaF_AMn13ypCr-BtVgwA@mail.gmail.com> <CAK_ErkjJ8ZYhtAoOC0p-DRpd5JQfb6aGWgU2T6uW5ZLtxjY2Mg@mail.gmail.com> <55EE9EEC.1060907@rece.vub.ac.be> <CAK_ErkgQPBxSc+zs7c2tGpGgQQ7s_SsAyJFB6qwcvJg68B9g0w@mail.gmail.com> <55EEDD37.5090602@gmx.com> <CAK_ErkjdWXG7aQ=Q23tq-ZVuyX_etdrC939WtCAPkeu2_5SZ8A@mail.gmail.com> <mailman.243.1441760967.8327.python-list@python.org> <55f072aa$0$1669$c3e8da3$5496439d@news.astraweb.com> <mailman.281.1441825163.8327.python-list@python.org> <55f1a8df$0$1660$c3e8da3$5496439d@news.astraweb.com> <1441902711.3168172.380049449.32E41922@webmail.messagingengine.com> <CAPTjJmpngxHPM6_WMyGGizwMww1LKvFtAM5bXyf6inzUJK9Yiw@mail.gmail.com> <1441915664.3216384.380230649.5CF010BC@webmail.messagingengine.com>
Date Fri, 11 Sep 2015 11:35:40 +1000
Subject Re: Python handles globals badly.
From Chris Angelico <rosuav@gmail.com>
Cc "python-list@python.org" <python-list@python.org>
Content-Type text/plain; charset=UTF-8
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.20+
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <https://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 <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.347.1441935344.8327.python-list@python.org> (permalink)
Lines 29
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1441935344 news.xs4all.nl 23735 [2001:888:2000:d::a6]:35399
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:96312

Show key headers only | View raw

On Fri, Sep 11, 2015 at 6:07 AM,  <random832@fastmail.us> wrote:
> On Thu, Sep 10, 2015, at 12:48, Chris Angelico wrote:
>> Having assignment be a statement (and therefore illegal in a loop
>> condition) makes sense. Having it be an expression that yields a
>> useful or predictable value makes sense. Having it be an expression,
>> but not returning a value, doesn't.
>
> Why not? Having it not return a value (and thus be illegal in places
> that expect a value), but be legal in places like C's comma operator or
> Lisp's progn that do not use the value, would make logical sense. Your
> while loop could be written as something like "while (ch = getchar();
> ch): ..."
>
> The main purpose of this would be to prevent you from using it where a
> boolean is expected, which wouldn't be necessary if Python hadn't
> repeated C's mistake of spelling it "=".

I didn't say it doesn't make _technical_ sense to have an expression
without  value, but it doesn't make any _useful_ sense. In previous
posts I consciously avoided this wording, but I'm going to say it, and
clink my pun jar: There's no value in doing it that way.

In order to make this valueless expression useful, you have to first
have some sort of expression that consists of two subexpressions,
where one of them is ignored. (Like C's comma operator.) Why do it?
Why not simply have the expression yield a useful value - or else not
be an expression, such that you have two _statements_?

ChrisA

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: Python handles globals badly. tdev@freenet.de - 2015-09-02 11:47 -0700
  Re: Python handles globals badly. tdev@freenet.de - 2015-09-02 12:32 -0700
  Re: Python handles globals badly. Emile van Sebille <emile@fenx.com> - 2015-09-02 12:34 -0700
  Re: Python handles globals badly. Ian Kelly <ian.g.kelly@gmail.com> - 2015-09-02 13:38 -0600
  Re: Python handles globals badly. "Sven R. Kunze" <srkunze@mail.de> - 2015-09-02 22:08 +0200
  Re: Python handles globals badly. MRAB <python@mrabarnett.plus.com> - 2015-09-02 21:22 +0100
  Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-02 22:19 +0100
  Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-03 02:16 +0100
  Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-03 11:49 +1000
  Re: Python handles globals badly. Vladimir Ignatov <kmisoft@gmail.com> - 2015-09-04 20:05 -0400
  Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-08 10:40 +0200
  Re: Python handles globals badly. Vladimir Ignatov <kmisoft@gmail.com> - 2015-09-08 07:55 -0400
  Re: Python handles globals badly. Akira Li <4kir4.1i@gmail.com> - 2015-09-08 15:35 +0300
  Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-08 14:05 +0100
  Re: Python handles globals badly. Ian Kelly <ian.g.kelly@gmail.com> - 2015-09-08 08:31 -0600
    Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-09 01:56 +1000
      Re: Python handles globals badly. Michael Torrie <torriem@gmail.com> - 2015-09-08 17:55 -0600
        Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-09 13:23 +1000
          Re: Python handles globals badly. Christian Gollwitzer <auriocus@gmx.de> - 2015-09-09 18:09 +0200
            Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-10 03:22 +1000
              Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-10 03:27 +1000
              Re: Python handles globals badly. William Ray Wing <wrw@mac.com> - 2015-09-09 13:59 -0400
              Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-09 20:20 +0100
                Re: Python handles globals badly. Peter Pearson <pkpearson@nowhere.invalid> - 2015-09-10 20:49 +0000
              Re: Python handles globals badly. MRAB <python@mrabarnett.plus.com> - 2015-09-09 20:22 +0100
              Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-10 05:27 +1000
      Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-09 12:42 +0200
      Re: Python handles globals badly. Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-09-09 09:33 -0400
  Re: Python handles globals badly. random832@fastmail.us - 2015-09-08 12:13 -0400
  Re: Python handles globals badly. MRAB <python@mrabarnett.plus.com> - 2015-09-08 18:41 +0100
  Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-08 23:41 +0100
  Re: Python handles globals badly. MRAB <python@mrabarnett.plus.com> - 2015-09-09 00:20 +0100
  Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-09 00:32 +0100
  Re: Python handles globals badly. Random832 <random832@fastmail.com> - 2015-09-08 20:02 -0400
    Re: Python handles globals badly. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-11 10:23 +0200
  Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-09 02:09 +0100
    Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-10 03:55 +1000
      Re: Python handles globals badly. Laura Creighton <lac@openend.se> - 2015-09-09 20:05 +0200
      Re: Python handles globals badly. Emile van Sebille <emile@fenx.com> - 2015-09-09 11:23 -0700
        Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-10 22:20 +1000
      Re: Python handles globals badly. "Sven R. Kunze" <srkunze@mail.de> - 2015-09-09 20:26 +0200
        Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-11 01:50 +1000
      Re: Python handles globals badly. random832@fastmail.us - 2015-09-09 14:59 -0400
        Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-11 01:59 +1000
          Re: Python handles globals badly. random832@fastmail.us - 2015-09-10 12:31 -0400
            Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-11 04:13 +1000
              Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-11 04:33 +1000
              Re: Python handles globals badly. Jussi Piitulainen <harvesting@makes.email.invalid> - 2015-09-10 22:11 +0300
              Re: Python handles globals badly. random832@fastmail.us - 2015-09-10 16:30 -0400
          Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-11 02:48 +1000
          Re: Python handles globals badly. alister <alister.nospam.ware@ntlworld.com> - 2015-09-10 19:56 +0000
          Re: Python handles globals badly. random832@fastmail.us - 2015-09-10 16:07 -0400
          Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-11 11:35 +1000
          Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-11 12:19 +0200
            Re: Python handles globals badly. Marko Rauhamaa <marko@pacujo.net> - 2015-09-11 14:59 +0300
              Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-14 09:13 +0200
      Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-10 05:00 +1000
      Re: Python handles globals badly. Laura Creighton <lac@openend.se> - 2015-09-09 21:14 +0200
      Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-10 05:18 +1000
        Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-10 22:18 +1000
          Re: Python handles globals badly. jkn <jkn_gg@nicorp.f9.co.uk> - 2015-09-10 08:09 -0700
          Re: Python handles globals badly. rurpy@yahoo.com - 2015-09-10 12:04 -0700
            Re: Python handles globals badly. Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-09-10 20:33 -0400
            Re: Python handles globals badly. Gene Heskett <gheskett@wdtv.com> - 2015-09-10 22:19 -0400
            Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-12 03:35 +0100
            Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-12 05:11 +0100
            Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-12 05:38 +0100
            Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-12 16:52 +0100
            Re: Python handles globals badly. Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-09-12 12:24 -0400
            Re: Python handles globals badly. Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-09-12 12:29 -0400
            Re: Python handles globals badly. MRAB <python@mrabarnett.plus.com> - 2015-09-12 18:09 +0100
            Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-12 22:57 +0100
            Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-12 23:05 +0100
            Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-12 23:07 +0100
      Re: Python handles globals badly. "Sven R. Kunze" <srkunze@mail.de> - 2015-09-09 21:21 +0200
      Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-09 20:24 +0100
      Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-09 20:57 +0100
      Re: Python handles globals badly. Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-09 21:15 +0100
      Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-10 09:27 +0200
        Re: Python handles globals badly. Marko Rauhamaa <marko@pacujo.net> - 2015-09-10 10:49 +0300
      Re: Python handles globals badly. Michael Torrie <torriem@gmail.com> - 2015-09-10 08:21 -0600
      Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-11 09:28 +0200
        Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-12 13:48 +1000
          Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-14 10:30 +0200
            Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-16 11:13 +1000
              Re: Python handles globals badly. Steven D'Aprano <steve@pearwood.info> - 2015-09-16 11:20 +1000
                Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-16 11:58 +1000
              Re: Python handles globals badly. Random832 <random832@fastmail.com> - 2015-09-15 21:54 -0400
              Re: Python handles globals badly. Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2015-09-16 10:51 +0200
      Re: Python handles globals badly. random832@fastmail.us - 2015-09-11 08:50 -0400
  Re: Python handles globals badly. Ben Finney <ben+python@benfinney.id.au> - 2015-09-09 11:26 +1000
  Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-09 11:41 +1000
  Re: Python handles globals badly. Mario Figueiredo <marfig@gmx.com> - 2015-09-09 03:43 +0100
  Re: Python handles globals badly. Chris Angelico <rosuav@gmail.com> - 2015-09-09 13:03 +1000
  Re: Python handles globals badly. Ben Finney <ben+python@benfinney.id.au> - 2015-09-09 15:53 +1000

csiph-web