Path: csiph.com!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 0.171 X-Spam-Level: * X-Spam-Evidence: '*H*': 0.69; '*S*': 0.03; 'argument': 0.05; 'mrab': 0.05; '21,': 0.07; 'args)': 0.09; 'python': 0.11; 'sheer': 0.16; 'language': 0.16; 'wrote:': 0.18; '>>>': 0.22; 'header:User- Agent:1': 0.23; 'guys': 0.24; 'mention': 0.26; 'skip:" 20': 0.27; 'header:In-Reply-To:1': 0.27; 'function': 0.29; 'designer': 0.30; '+0100,': 0.31; '>>>>': 0.31; "d'aprano": 0.31; 'omitted': 0.31; 'steven': 0.31; 'terminate': 0.31; 'trivial': 0.31; "we're": 0.32; 'fri,': 0.33; 'johnson': 0.35; 'himself': 0.36; 'two': 0.37; 'expected': 0.38; 'somebody': 0.38; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'how': 0.40; 'ian': 0.60; 'worry': 0.60; 'details.': 0.61; 'skip:* 10': 0.61; "you've": 0.63; 'such': 0.63; 'determine': 0.67; 'hardly': 0.84; 'received:195.238': 0.84; 'received:195.238.6': 0.84; 'received:belgacom.be': 0.84; 'received:isp.belgacom.be': 0.84; 'subject:Value': 0.84; 'genius': 0.91; 'rick': 0.93; '2013': 0.98 X-Belgacom-Dynamic: yes X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnIDACW2xVFbtrjL/2dsb2JhbAANToY/vHsDAYERgxcBAQEEOEARCxgJFg8JAwIBAgFFEwYCArIziW6IB45qZhaDSwOXQ5RV Date: Sat, 22 Jun 2013 16:40:37 +0200 From: Antoon Pardon User-Agent: Mozilla/5.0 (X11; Linux i686; rv:10.0.12) Gecko/20130116 Icedove/10.0.12 MIME-Version: 1.0 To: python-list@python.org Subject: Re: Default Value References: <7e6361d5-6619-4aaa-adda-8b5f01bde57f@googlegroups.com> <447dd1c6-1bb2-4276-a109-78d7a067b442@d8g2000pbe.googlegroups.com> <2e92b4c7-31be-40d2-a906-ab19f3630dfa@googlegroups.com> <51c477dd$0$29999$c3e8da3$5496439d@news.astraweb.com> <565a1c8f-6fd9-4bab-9834-076eaea527f8@googlegroups.com> <7e1ed740-df18-4978-b11d-8ca9c4b5bd04@googlegroups.com> <03e9544e-9d6d-4155-a793-56f0c22c7f7a@googlegroups.com> <51c4fab1$0$29999$c3e8da3$5496439d@news.astraweb.com> In-Reply-To: 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 24 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1371912105 news.xs4all.nl 15972 [2001:888:2000:d::a6]:50624 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:48925 Op 22-06-13 03:27, Ian Kelly schreef: > On Fri, Jun 21, 2013 at 7:15 PM, Steven D'Aprano > wrote: >> On Fri, 21 Jun 2013 23:49:51 +0100, MRAB wrote: >> >>> On 21/06/2013 21:44, Rick Johnson wrote: >> [...] >>>> Which in Python would be the "MutableArgumentWarning". >>>> >>>> *school-bell* >>>> >>> I notice that you've omitted any mention of how you'd know that the >>> argument was mutable. >> >> That's easy. Just call ismutable(arg). The implementation of ismutable is >> just an implementation detail, somebody else can work that out. A >> language designer of the sheer genius of Rick can hardly be expected to >> worry himself about such trivial details. > > While we're at it, I would like to petition for a function > terminates(f, args) that I can use to determine whether a function > will terminate before I actually call it. Are you two guys now egging on Rick Johnson?