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 0.027 X-Spam-Evidence: '*H*': 0.95; '*S*': 0.00; 'float': 0.07; 'keys,': 0.09; 'cc:addr:python-list': 0.11; 'from:addr:pobox.com': 0.16; 'from:addr:skip': 0.16; 'sender:addr:gmail.com': 0.17; 'wrote:': 0.18; 'cc:addr:python.org': 0.22; 'cc:2**0': 0.24; 'header:In- Reply-To:1': 0.27; 'chris': 0.29; 'am,': 0.29; 'message- id:@mail.gmail.com': 0.30; '>>>>': 0.31; 'up:': 0.31; 'received:google.com': 0.35; 'skip:x 10': 0.40; 'to:addr:gmail.com': 0.65; 'jul': 0.74; 'subject:For': 0.78 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=t9OGeKDeAuG2+DpQqp3BG733yomKzd5iWBQm/Ozcigg=; b=EM1p2x0fw15Gf9HWLNJxjxJAA22jZNOV/UZ5Th8+hHY0vTHNvUZKGAz2sgNwtGv/Uk O5hc6OqZ4Rs8qRaxQ1IsQKVZ3MhG7Q3TcZssg/x8K68aIjQbv/d1haXTkrM7J30NcRty GtskVAbfgksf1MjNJyKkV69/8TLTqAbNVeF+AEqvp75NZcMotc+qHiFX8CpZIVfjE/1q J9mANRo6cIXN979oW3+SB/KDOt01nAanIj7FhBoViIEfl1ZnFeTzNFnXA+BgMkE2Cmzw /WZxPEcaL6c1gKi4SUPylEeXBORbFa/FE/lVHR2ayi/30ZQvVe9Uaw7DtQYmhd8EGP/G vxQA== MIME-Version: 1.0 X-Received: by 10.50.61.244 with SMTP id t20mr6571757igr.0.1404833090329; Tue, 08 Jul 2014 08:24:50 -0700 (PDT) Sender: skip.montanaro@gmail.com In-Reply-To: References: <53BC05FB.4050707@jmunch.dk> Date: Tue, 8 Jul 2014 10:24:50 -0500 X-Google-Sender-Auth: TlXJkih5CbYYDUe4zwyzZ58q8T8 Subject: Re: NaN comparisons - Call For Anecdotes From: Skip Montanaro To: Chris Angelico Content-Type: text/plain; charset=UTF-8 Cc: "python-list@python.org" 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: 15 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1404833099 news.xs4all.nl 2933 [2001:888:2000:d::a6]:37583 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:74175 On Tue, Jul 8, 2014 at 10:19 AM, Chris Angelico wrote: > For hash keys, float object identity will successfully look them up: >>>> d={} >>>> d[float("nan")]=1 >>>> d[float("nan")]=2 >>>> x=float("nan") >>>> d[x]=3 >>>> d[x] > 3 >>>> d > {nan: 1, nan: 2, nan: 3} Neat! S