Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed1.news.xs4all.nl!xs4all!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 0.025 X-Spam-Evidence: '*H*': 0.95; '*S*': 0.00; '"if': 0.09; 'buggy': 0.16; 'leaks': 0.16; 'objection': 0.16; 'sentinel': 0.16; 'summarizes': 0.16; 'wrote:': 0.18; "python's": 0.19; 'seems': 0.21; 'machine': 0.22; 'header:In-Reply-To:1': 0.27; 'message-id:@mail.gmail.com': 0.30; 'test': 0.35; 'received:google.com': 0.35; 'to:addr:python- list': 0.38; 'pm,': 0.38; 'does': 0.39; 'legitimate': 0.39; 'to:addr:python.org': 0.39; 'mar': 0.68 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=TqyuipoeyOJruiEsRDz9e+BB+NPlaZ4fd8pmt9eHMl4=; b=mmYts3TfVlw4+pwSGwKuTlN3wS6cK9/DQkOiK7KnOstQStwvtgYAHWNojlkrDF17rw z4GmgBQArckmXzzuMvvYhzWgfOATu5PrQt/UZchtSp6PSJ3nrJcbhDwYIsWZV2w26e6X Yd/10pQkTrj42lbrmQ/UFrdd7B6hgvjqTKuwo6rC19M0G0fDUTOXlG6m4/PyhotE/cc4 lUdd9GBMtWg9cgwCEcfBmEFfQq7AYgZP5N10jdp9S4j90sp4Tp1VMFutoM0Dsgg99+Qa wONQ5n7PEQ4m4IgR5sdPV+Z+EMXw35a34vq9mxQdxo4Z5djblM8PkdZlaufK0gye8YAK vyGA== X-Received: by 10.66.41.106 with SMTP id e10mr3882579pal.109.1393992578452; Tue, 04 Mar 2014 20:09:38 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <164d209c-ba5e-449f-bc25-c27ebfb1fc0f@googlegroups.com> References: <53144e8d$0$2149$426a74cc@news.free.fr> <1d1dfa1b-b715-4d8f-9c12-f0d3dc1a22c9@googlegroups.com> <85ppm3httu.fsf@benfinney.id.au> <20140303155112.46e34ff8@bigbox.christie.dr> <87siqy7whs.fsf@elektro.pacujo.net> <53155c15$0$2923$c3e8da3$76491128@news.astraweb.com> <164d209c-ba5e-449f-bc25-c27ebfb1fc0f@googlegroups.com> From: Ian Kelly Date: Tue, 4 Mar 2014 21:08:58 -0700 Subject: Re: Reference To: Python Content-Type: text/plain; charset=ISO-8859-1 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: 8 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1393992587 news.xs4all.nl 2938 [2001:888:2000:d::a6]:44979 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:67792 On Tue, Mar 4, 2014 at 8:36 PM, Rustom Mody wrote: > * ... which summarizes my objection in this thread: Python's 'is' leaks the > machine abstraction. 'id' does it legitimately (somewhat), > 'is' does it illegitimately Well, since "if x == None" is buggy as a test for sentinel values, that means the only legitimate non-buggy way to do it is with "if id(x) == id(None)", which just seems gross to me.