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

Groups > comp.lang.python > #45093

Re: object.enable() anti-pattern

Path csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!rt.uk.eu.org!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path <python-python-list@m.gmane.org>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.020
X-Spam-Evidence '*H*': 0.96; '*S*': 0.00; 'patterns': 0.04; 'explicit': 0.07; 'agrees': 0.09; 'method,': 0.09; 'method:': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'constructor.': 0.16; 'fine.': 0.16; 'forbids': 0.16; 'kern': 0.16; 'naming': 0.16; 'programmers.': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'specific,': 0.16; 'underlying': 0.16; 'all.': 0.16; 'wrote:': 0.18; 'discussion': 0.18; 'bit': 0.19; 'file,': 0.19; 'not,': 0.20; 'separate': 0.22; 'header:User- Agent:1': 0.23; 'instead.': 0.24; 'interpret': 0.24; 'file.': 0.24; "i've": 0.25; 'permission': 0.26; 'pass': 0.26; 'least': 0.26; 'header:X-Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'idea': 0.28; 'point': 0.28; 'moved': 0.30; 'robert': 0.30; 'said,': 0.30; 'then.': 0.30; "i'm": 0.30; 'about.': 0.31; "d'aprano": 0.31; 'object.': 0.31; 'steven': 0.31; 'another': 0.32; 'open': 0.33; 'everyone': 0.33; 'entirely': 0.33; 'programmers': 0.33; 'sense': 0.34; "i'd": 0.34; 'but': 0.35; 'there': 0.35; 'curious': 0.36; 'done,': 0.36; 'instances': 0.36; 'object,': 0.36; 'done': 0.36; 'useful': 0.36; 'should': 0.36; 'experience,': 0.37; 'wrong': 0.37; 'others.': 0.38; 'security,': 0.38; 'to:addr:python-list': 0.38; 'does': 0.39; 'to:addr:python.org': 0.39; 'either': 0.39; 'skip:p 20': 0.39; 'received:org': 0.40; 'most': 0.60; 'first': 0.61; 'discuss': 0.62; "you've": 0.63; 'show': 0.63; 'our': 0.64; 'more': 0.64; 'talking': 0.65; 'world': 0.66; 'believe': 0.68; 'natural': 0.68; 'design.': 0.68; 'limit': 0.70; 'continuum': 0.84; 'doubts': 0.84; 'eco': 0.84; 'entity,': 0.84; 'rubbish': 0.84; 'subject:skip:o 10': 0.84; 'terrible': 0.84; 'novice': 0.91; 'reasons,': 0.91; 'story.': 0.93
X-Injected-Via-Gmane http://gmane.org/
To python-list@python.org
From Robert Kern <robert.kern@gmail.com>
Subject Re: object.enable() anti-pattern
Date Fri, 10 May 2013 13:19:05 +0100
References <518a123c$0$11094$c3e8da3@news.astraweb.com> <Z1Eit.289$oB7.283@newsfe02.iad> <518b32ef$0$11120$c3e8da3@news.astraweb.com> <roy-8428A6.09074209052013@news.panix.com> <518be931$0$29997$c3e8da3$5496439d@news.astraweb.com> <mailman.1501.1368124461.3114.python-list@python.org> <518c5bbc$0$29997$c3e8da3$5496439d@news.astraweb.com> <roy-6D8B98.23095509052013@news.panix.com> <518c7f8e$0$29997$c3e8da3$5496439d@news.astraweb.com> <Hm0jt.6$I26.5@newsfe26.iad> <518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
Mime-Version 1.0
Content-Type text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding 7bit
X-Gmane-NNTP-Posting-Host 213.1.240.226
User-Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130328 Thunderbird/17.0.5
In-Reply-To <518cd360$0$29997$c3e8da3$5496439d@news.astraweb.com>
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.1527.1368188358.3114.python-list@python.org> (permalink)
Lines 49
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1368188358 news.xs4all.nl 16003 [2001:888:2000:d::a6]:57746
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:45093

Show key headers only | View raw

On 2013-05-10 12:00, Steven D'Aprano wrote:

> But either way, that's fine. You've found an object where it does make
> sense to have an explicit "make it go" method: first one entity has
> permission to construct the object, but not to open the underlying file.
> Another entity has permission to open the underlying file, but not to
> create the object. I have no idea whether this is a reasonable security
> design or not, it actually sounds a bit rubbish to me but what do I know?
> So let's treat it as a reasonable design.
>
> As I've said, repeatedly, that's not what I'm talking about.
>
> When you DON'T have useful things that can be done with the object before
> calling "enable", then it is an anti-pattern to require a separate call
> to "enable" method, and the enable functionality should be moved into the
> object constructor. If you DO have useful things that can be done, like
> pass the object to another entity, for security, then that's a whole
> 'nuther story.

I'd be curious to see in-the-wild instances of the anti-pattern that you are 
talking about, then. I think everyone agrees that entirely unmotivated "enable" 
methods should be avoided, but I have my doubts that they come up very often. Do 
programmers have a natural tendency to make an extra, completely unnecessary 
method? I would think that they have a natural tendency to the opposite.

In my experience, everyone has a reason in mind when they follow a 
pattern/anti-pattern. It is pretty rare that someone just does some specific, 
nameable thing for no reason at all. There is no need to call out an 
anti-pattern for which no one has a reason to do it. But there is a continuum of 
reasons. Some reasons are better than others. Some reasons only apply in a small 
set of circumstances but seem like they would apply more generally, at least to 
novice programmers. Programmers can be wrong about what they think the 
(anti-)pattern actually achieves. The whole point of naming an anti-pattern is 
to discuss those reasons, show where they are misapplied, where YAGNI, why 
novices overuse it, other patterns that should be used instead, and also the 
circumstances where it is actually a good pattern instead.

To artificially limit the discussion of the anti-pattern to the trivial, 
entirely unmotivated case forbids most of the interesting and instructive parts 
of the conversation.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco

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

Thread

object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-08 08:52 +0000
  Re: object.enable() anti-pattern Christian Heimes <christian@python.org> - 2013-05-08 11:51 +0200
  Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-08 11:13 +0100
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-08 12:30 +0000
  Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-08 09:17 -0400
  Re: object.enable() anti-pattern Duncan Booth <duncan.booth@invalid.invalid> - 2013-05-08 14:27 +0000
    Re: object.enable() anti-pattern Dan Sommers <dan@tombstonezero.net> - 2013-05-09 02:38 +0000
      Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 05:37 +0000
        Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-09 15:52 +1000
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 03:12 +0000
  Re: object.enable() anti-pattern Dan Sommers <dan@tombstonezero.net> - 2013-05-09 02:42 +0000
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 05:23 +0000
      Re: object.enable() anti-pattern Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-09 02:41 -0400
      Re: object.enable() anti-pattern Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-09 19:54 +1200
        Re: object.enable() anti-pattern Cameron Simpson <cs@zip.com.au> - 2013-05-09 18:23 +1000
          Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 11:30 +0000
            Re: object.enable() anti-pattern Cameron Simpson <cs@zip.com.au> - 2013-05-10 09:36 +1000
              Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 05:00 +0000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 01:50 -0400
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 09:47 +0000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 09:22 -0400
                Re: object.enable() anti-pattern Cameron Simpson <cs@zip.com.au> - 2013-05-11 08:25 +1000
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-10 20:16 -0700
                Re: object.enable() anti-pattern Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2013-05-11 06:21 +0200
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-10 21:00 -0700
                Re: object.enable() anti-pattern Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-11 15:04 -0400
        Re: object.enable() anti-pattern Greg Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-10 10:56 +1200
      Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-09 09:07 -0400
        Re: object.enable() anti-pattern Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-05-09 14:51 +0100
        Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 18:21 +0000
          Re: object.enable() anti-pattern MRAB <python@mrabarnett.plus.com> - 2013-05-09 19:34 +0100
            Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 02:30 +0000
              Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-09 23:09 -0400
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-09 20:19 -0700
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-10 13:46 +1000
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 05:03 +0000
                Re: object.enable() anti-pattern Dan Sommers <dan@tombstonezero.net> - 2013-05-10 06:22 +0000
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 11:00 +0000
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-10 13:19 +0100
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 10:01 -0400
                Re: object.enable() anti-pattern Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-05-10 15:29 +0100
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 10:37 -0400
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 00:46 +1000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 10:54 -0400
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 01:09 +1000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 11:21 -0400
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 01:44 +1000
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-10 16:33 +0100
                Re: object.enable() anti-pattern Serhiy Storchaka <storchaka@gmail.com> - 2013-05-10 18:44 +0300
                Re: object.enable() anti-pattern André Malo <ndparker@gmail.com> - 2013-05-11 17:33 +0200
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-12 02:04 +1000
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-10 18:20 +0100
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-11 07:51 +0000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-11 09:31 -0400
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-11 20:55 +0100
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-12 08:39 +1000
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 03:24 +1000
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-10 19:43 -0700
                Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-12 11:48 -0500
                Re: object.enable() anti-pattern Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-12 16:23 -0400
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-09 20:51 -0700
              Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-10 13:08 +1000
          Re: object.enable() anti-pattern roy@panix.com (Roy Smith) - 2013-05-09 14:59 -0400
            Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-10 07:55 +1000
      Re: object.enable() anti-pattern Nobody <nobody@nowhere.com> - 2013-05-10 17:59 +0100
        Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 13:32 -0400
          Re: object.enable() anti-pattern Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-11 15:24 -0400
        Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-11 07:05 +0000
  Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-08 19:53 -0700
  Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-08 19:56 -0700
  Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-09 06:08 -0500
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 11:51 +0000
    Re: object.enable() anti-pattern Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-10 11:43 +1200
      Re: object.enable() anti-pattern Michael Speer <knomenet@gmail.com> - 2013-05-09 20:18 -0400
        Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-09 20:50 -0400
      Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-12 12:14 -0500
      Re: object.enable() anti-pattern Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-12 16:03 -0400
      Re: object.enable() anti-pattern Greg Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-13 11:18 +1200
      Re: object.enable() anti-pattern Fábio Santos <fabiosantosart@gmail.com> - 2013-05-13 07:32 +0100
      Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-13 17:36 +1000
      Re: object.enable() anti-pattern Fábio Santos <fabiosantosart@gmail.com> - 2013-05-13 09:09 +0100
      Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-13 08:15 -0500

csiph-web