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

Groups > comp.lang.python > #80558

Re: I love assert

Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path <ethan@stoneleaf.us>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.007
X-Spam-Evidence '*H*': 0.99; '*S*': 0.00; 'tool,': 0.07; 'from:addr:ethan': 0.09; 'from:addr:stoneleaf.us': 0.09; 'from:name:ethan furman': 0.09; 'message-id:@stoneleaf.us': 0.09; 'statements': 0.09; 'tests,': 0.09; '~ethan~': 0.09; 'python': 0.11; 'intended.': 0.16; 'pythonistas': 0.16; 'removed,': 0.16; 'substitute': 0.16; 'exception': 0.16; 'wrote:': 0.18; 'all,': 0.19; 'not,': 0.20; 'coding': 0.22; 'header:User-Agent:1': 0.23; "aren't": 0.24; 'removed.': 0.24; 'question': 0.24; 'somewhere': 0.26; 'gets': 0.27; 'header:In-Reply-To:1': 0.27; 'point': 0.28; 'am,': 0.29; "doesn't": 0.30; 'assert': 0.31; 'run': 0.32; 'basic': 0.35; 'but': 0.35; 'there': 0.35; 'curious': 0.36; 'data,': 0.36; 'impression': 0.36; 'useful': 0.36; 'should': 0.36; 'unit': 0.37; 'easily': 0.37; 'to:addr:python-list': 0.38; 'bad': 0.39; 'to:addr:python.org': 0.39; 'truly': 0.60; 'most': 0.60; 'received:173': 0.61; 'specialized': 0.65; 'gotten': 0.74; '"active': 0.84; 'action.': 0.84; 'am.': 0.91; 'passive': 0.91
Date Tue, 11 Nov 2014 12:08:16 -0800
From Ethan Furman <ethan@stoneleaf.us>
User-Agent Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121010 Thunderbird/16.0.1
MIME-Version 1.0
To python-list@python.org
Subject Re: I love assert
References <96c138e4-ab95-4e5f-a0c8-e696b5a926bb@googlegroups.com>
In-Reply-To <96c138e4-ab95-4e5f-a0c8-e696b5a926bb@googlegroups.com>
Content-Type text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding 7bit
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 <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.15688.1415736500.18130.python-list@python.org> (permalink)
Lines 23
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1415736500 news.xs4all.nl 2953 [2001:888:2000:d::a6]:50244
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:80558

Show key headers only | View raw

On 11/11/2014 11:40 AM, Peter Cacioppi wrote:
>
> I get the impression that most Pythonistas aren't as habituated with assert statements
>  as I am. Is that just a misimpression on my part? If not, is there a good reason to
>  assert less with Python than other languages?
>
> As far as I can tell, Python supports assert perfectly well. When run with the optimization
>  flagging, the asserts are truly removed.
>
> I think one needs to take care with some basic assert coding - it's not a substitute for
>  unit tests, it doesn't absolve you of normal exception responsibilities, and, most of all,
>  it should be used for passive inspection and not action. But given these guidelines, I
>  still find it very useful as "active comments".

asserts are a specialized tool, easily abused.  Sounds like you are using them exactly as intended.

The key question to ask (if one is curious whether one is using assert correctly) is:  if all the asserts are removed, 
and my programs gets bad data, will it keep going as if it had gotten good data?  Or, will it fail at the point it 
should have failed, or will it fail somewhere else?

--
~Ethan~

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

Thread

I love assert Peter Cacioppi <peter.cacioppi@gmail.com> - 2014-11-11 11:40 -0800
  Re: I love assert Ben Finney <ben+python@benfinney.id.au> - 2014-11-12 07:03 +1100
    Re: I love assert Grant Edwards <invalid@invalid.invalid> - 2014-11-11 21:43 +0000
  Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-11 12:08 -0800
  Re: I love assert Rob Gaddi <rgaddi@technologyhighland.invalid> - 2014-11-11 12:20 -0800
  Re: I love assert Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-11 20:34 +0000
  Re: I love assert TP <wingusr@gmail.com> - 2014-11-11 12:57 -0800
  Re: I love assert Terry Reedy <tjreedy@udel.edu> - 2014-11-11 17:34 -0500
  Re: I love assert Ben Finney <ben+python@benfinney.id.au> - 2014-11-12 09:52 +1100
  Re: I love assert Tim Chase <python.list@tim.thechases.com> - 2014-11-11 17:03 -0600
  Re: I love assert Peter Cacioppi <peter.cacioppi@gmail.com> - 2014-11-11 15:02 -0800
  Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-11 15:38 -0800
  Re: I love assert Dan Stromberg <drsalists@gmail.com> - 2014-11-11 17:56 -0800
  Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-12 13:21 +1100
  Re: I love assert Ben Finney <ben+python@benfinney.id.au> - 2014-11-12 13:35 +1100
    Re: I love assert Grant Edwards <invalid@invalid.invalid> - 2014-11-12 14:10 +0000
  Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-12 13:44 +1100
    Re: I love assert wxjmfauth@gmail.com - 2014-11-11 23:14 -0800
  Re: I love assert Terry Reedy <tjreedy@udel.edu> - 2014-11-12 03:29 -0500
  Re: I love assert Anton <anton.schattenfeld@gmail.com> - 2014-11-12 12:53 -0800
    Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-12 23:41 +0200
      Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-12 13:52 -0800
        Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-12 23:56 +0200
          Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 15:04 -0700
            Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:13 -0800
              Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 15:41 -0700
                Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:48 -0800
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:01 +0200
                Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-15 10:40 +1100
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 02:12 +0200
                Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-15 12:04 +1100
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 03:30 +0200
                Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-15 12:48 +1100
                Re: I love assert Tim Chase <python.list@tim.thechases.com> - 2014-11-14 20:14 -0600
                Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-15 13:16 +1100
                Re: I love assert albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-11-29 17:35 +0000
                Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 16:02 -0700
                Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 15:43 -0800
                Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 10:10 +1100
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:23 +0200
                Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 10:27 +1100
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:31 +0200
              Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-12 14:47 -0800
                Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-14 22:37 +1100
                Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-14 09:40 -0700
          Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 15:07 -0700
            Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 00:47 +0200
              Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-12 14:56 -0800
              Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 09:58 +1100
              Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 16:05 -0700
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:12 +0200
              Re: I love assert Lie Ryan <lie.1296@gmail.com> - 2014-11-14 01:09 +1100
        Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-14 22:33 +1100
          Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-14 10:18 -0800
            Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-14 21:12 +0200
              Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-14 12:41 -0800
                Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-14 22:50 +0200
            Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-15 13:58 +1100
              Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-14 20:09 -0800
                Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-17 13:09 +1100
                Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-16 19:25 -0800
      Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:00 -0800
        Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:04 -0800
          Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 00:34 +0200
    Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 09:43 +1100
  Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-14 22:15 +1100
  Re: I love assert Richard Riehle <rriehle@itu.edu> - 2014-11-14 14:09 -0800
    Decorators (was: Re: I love assert) Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 00:18 +0200
      Re: Decorators Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-14 22:37 +0000
        Re: Decorators Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 00:47 +0200
      Re: Decorators (was: Re: I love assert) Richard Riehle <rriehle@itu.edu> - 2014-11-14 18:19 -0800
        Re: Decorators (was: Re: I love assert) Mayank Tripathi <oquanox@gmail.com> - 2014-11-15 02:36 +0000
        Re: Decorators (was: Re: I love assert) Tim Chase <python.list@tim.thechases.com> - 2014-11-14 20:30 -0600
          Re: Decorators Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 09:00 +0200
            Re: Decorators Grant Edwards <invalid@invalid.invalid> - 2014-11-15 15:32 +0000
        Re: Decorators (was: Re: I love assert) Richard Riehle <rriehle@itu.edu> - 2014-11-14 23:42 -0800
        Re: Decorators Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-15 13:12 +0000
          Re: Decorators Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 15:24 +0200
            Re: Decorators Terry Reedy <tjreedy@udel.edu> - 2014-11-15 15:28 -0500
        Re: Decorators (was: Re: I love assert) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-16 02:39 +1100
  Re: I love assert TP <wingusr@gmail.com> - 2014-11-27 01:22 -0800
    Re: I love assert alister <alister.nospam.ware@ntlworld.com> - 2014-11-27 09:59 +0000
      Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-29 12:30 +1100
        Re: I love assert MRAB <python@mrabarnett.plus.com> - 2014-11-29 02:56 +0000
          Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-29 20:31 +1100
            Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-29 21:40 +1100
            Re: I love assert MRAB <python@mrabarnett.plus.com> - 2014-11-29 19:49 +0000
        Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-29 14:02 +1100
        Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-29 14:33 -0800
          Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-30 19:18 +1100
            Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-30 11:34 -0800

csiph-web