Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!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 0.033 X-Spam-Evidence: '*H*': 0.93; '*S*': 0.00; 'value,': 0.04; 'cc:addr :python-list': 0.11; 'def': 0.12; '1.0)': 0.16; '__lt__': 0.16; '__ne__': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'implemented,': 0.16; 'wrote:': 0.18; 'cc:addr:python.org': 0.22; 'fairly': 0.24; 'cc:2**0': 0.24; 'header:In-Reply-To:1': 0.27; 'am,': 0.29; 'message- id:@mail.gmail.com': 0.30; 'class': 0.32; 'fri,': 0.33; 'skip:_ 10': 0.34; 'but': 0.35; 'received:google.com': 0.35; 'false': 0.36; 'should': 0.36; 'easily': 0.37; 'more': 0.64; 'useful.': 0.68; 'jul': 0.74; 'subject:For': 0.78; 'truth': 0.81; 'to:none': 0.92 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=1ydhkTZ/6V0IDuNbHyMJY85pogrKx6OYhSyRo7lsHMs=; b=QvjIGaT6XX5WLzGAJYlZA/ABKM0eGimrPYBJXlZG4B9CbKzFpMJ33DSI+GUKgg+0sd owYRS1aUWj/NMyLtMTFsYAxIM0cqlFJq1Y84vyOcJy17TV3U/FvK0AhQ7IcKL7+gJvTY ZB3jNTe+5OxM4kj3Tsyr7mVpk5VEfmT4jhdWF2FTt6Bcbv96IdLyEXGXTSvoWByGC4WG BJ4U5bJ/zsmas05Mr38jB4nfa4kKvc1y0YZoa+EdNq0fGm6IUbqSuR5vHJ0hGFNmYbnY v1v8Ke4IDRMU7FvlD/1lsXdBSKZCAFxFeffJM2oDEKHVpiZ4z4UjR2qAcKyuqvAW+DiJ 8DNg== MIME-Version: 1.0 X-Received: by 10.220.1.70 with SMTP id 6mr20660199vce.62.1405623596370; Thu, 17 Jul 2014 11:59:56 -0700 (PDT) In-Reply-To: References: <53BC05FB.4050707@jmunch.dk> <53BD70F4.4000504@stoneleaf.us> <53BDAF90.8010709@jmunch.dk> Date: Fri, 18 Jul 2014 04:59:56 +1000 Subject: Re: NaN comparisons - Call For Anecdotes From: Chris Angelico Cc: "python-list@python.org" Content-Type: text/plain; charset=UTF-8 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: 14 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1405623598 news.xs4all.nl 2898 [2001:888:2000:d::a6]:56175 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:74676 On Fri, Jul 18, 2014 at 4:49 AM, Johann Hibschman wrote: > In > principle, (NA == 1.0) should be a NA (missing) truth value, as should > (NA == NA), but in practice having it be False is more useful. This is actually fairly easily implemented, if you ever want it. class NAType: def __repr__(self): return "NA" def __eq__(self, other): return self __lt__ = __gt__ = __le__ = __ge__ = __ne__ = __eq__ NA = NAType() ChrisA