Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!ecngs!feeder2.ecngs.de!newsfeed.freenet.ag!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'bug': 0.02; 'python.': 0.04; 'bug.': 0.07; 'differently.': 0.07; 'imply': 0.07; 'python': 0.08; 'bug?': 0.09; 'mutable': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:80.91.229.12': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'received:lo.gmane.org': 0.09; 'underlying': 0.09; 'am,': 0.12; 'list?': 0.13; 'enigma': 0.16; 'kern': 0.16; 'likewise': 0.16; 'subject:=': 0.16; 'language': 0.17; 'wrote:': 0.18; '>>>': 0.18; 'arguments': 0.18; 'dec': 0.22; 'header:In-Reply-To:1': 0.22; 'there.': 0.24; 'function': 0.27; 'asking': 0.28; 'interpret': 0.29; 'pm,': 0.29; 'argue': 0.30; 'feature,': 0.30; 'means,': 0.30; 'chris': 0.30; 'minor': 0.32; 'header:User-Agent:1': 0.33; 'header:X-Complaints-To:1': 0.33; 'that,': 0.33; 'fri,': 0.34; 'to:addr:python-list': 0.34; 'too': 0.34; 'calling': 0.34; 'url:python': 0.36; 'url:pipermail': 0.37; 'but': 0.37; 'steven': 0.38; 'received:org': 0.38; 'some': 0.38; 'hold': 0.38; 'mailing': 0.39; 'url:org': 0.39; 'either': 0.39; 'should': 0.39; 'to:addr:python.org': 0.40; 'might': 0.40; 'more': 0.61; '2011': 0.61; 'world': 0.62; 'received:86': 0.63; 'our': 0.64; 'believe': 0.65; '10:22': 0.84; 'deliberate': 0.84; 'difficulties': 0.84; 'gotcha': 0.84; 'nonsense.': 0.84; 'rusi': 0.84; 'eco': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Robert Kern Subject: Re: what does 'a=b=c=[]' do Date: Fri, 23 Dec 2011 13:10:54 +0000 References: <18f78d0d-1e70-4c7b-9033-1422e6edb6db@t13g2000yqg.googlegroups.com> <10c62dac-2750-4f08-8962-21952c1c0a0b@v31g2000prg.googlegroups.com> <5a7a7aab-a320-4429-a130-ffcfcf0ac174@v24g2000prn.googlegroups.com> <4ef44c6f$0$29973$c3e8da3$5496439d@news.astraweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: cpc24-cmbg15-2-0-cust204.5-4.cable.virginmedia.com User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:8.0) Gecko/20111105 Thunderbird/8.0 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 37 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1324645872 news.xs4all.nl 6926 [2001:888:2000:d::a6]:39456 X-Complaints-To: abuse@xs4all.nl Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:17800 On 12/23/11 10:22 AM, rusi wrote: > On Dec 23, 2:39 pm, Steven D'Aprano +comp.lang.pyt...@pearwood.info> wrote: >> On Fri, 23 Dec 2011 00:38:07 -0800, rusi wrote: >>> Likewise function arguments that default to mutable entities is a known >>> gotcha of python which is best treated as a bug in python. >> >> Nonsense. It is a feature, not a bug. > > Tsk Tsk How can python have a bug? And that too on the python mailing > list? > > Others however feel differently. See Chris Rebert's > http://mail.python.org/pipermail/python-ideas/2007-January/000073.html > and the links cited there. > >> >> Some people might argue that it is a mistake, a minor feature which >> allegedly causes more difficulties than benefits. I do not hold with that >> idea. But either way, it is not a bug to be fixed, but a deliberate >> consequence of intended semantics. > > I did not ask or imply that it should be 'fixed', just that language > misfeatures should be treated with extra care. "Bug" means, roughly, "something that should be fixed" not just any "thing that has some unwanted consequences". So yes, by calling it a bug you are asking and implying just that. If you don't mean that, don't use the word "bug". -- 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