Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.mixmin.net!rt.uk.eu.org!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 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'python,': 0.02; '21,': 0.07; 'subject:bug': 0.07; '0.02': 0.09; '0.1': 0.09; 'cc:addr :python-list': 0.11; 'python': 0.11; 'bug': 0.12; '0.01': 0.16; '0.03': 0.16; '0.04': 0.16; '0.06': 0.16; '0.07': 0.16; '0.09': 0.16; '0.19': 0.16; 'url:ftp': 0.16; 'subject:python': 0.16; 'sat,': 0.16; 'wrote:': 0.18; 'seems': 0.21; 'cc:addr:python.org': 0.22; 'install': 0.23; 'cc:2**0': 0.24; 'compare': 0.26; 'this:': 0.26; 'header:In-Reply-To:1': 0.27; 'am,': 0.29; 'message- id:@mail.gmail.com': 0.30; "i'm": 0.30; 'url:mailman': 0.30; 'code': 0.31; 'url:python': 0.33; 'but': 0.35; 'received:google.com': 0.35; 'crazy': 0.36; 'url:listinfo': 0.36; 'subject:?': 0.36; 'url:org': 0.36; 'url:mail': 0.40; 'read': 0.60; 'url:3': 0.61; 'url:4': 0.69 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 :cc:content-type; bh=nDoO2rKJEI9QKgPbpnlDqoc/0flRAqn1vPmPH2vr9YI=; b=wvgmH2L2VbcQbu39ex2OdAuAhpkVNbDw2uGcH9kEXI2nY1MDoC4Sp56Z/Rk5PpvRNj qu815N/ipHqCMQJRZ448qMOc7ldlEgV+GpL0ZYKWXMRQxCFD7JsD/XSMWKW828SyrbtD wT0bA/wcqRsBi8QmJlm0+qT2dN0Gyao3Zw2xQoi3U3yFjWnOJbbx0XnfGo32FaTTxVCP cIZwn0MBScuJcEUKMNpEjjv3oFLaCnChmk43bLbfaVhm3LdXvQc3ev2LQkBE2op7pisk WLn3rTh5iofvfo/lD1nSd4sjDhA2Aa0+Y4f3mDbKFYPOU3GAQwggG4KLPgdaMibxYsPS bfnw== X-Received: by 10.140.109.118 with SMTP id k109mr9683427qgf.98.1403312812820; Fri, 20 Jun 2014 18:06:52 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: From: INADA Naoki Date: Sat, 21 Jun 2014 10:06:32 +0900 Subject: Re: python 3.44 float addition bug? To: FraserL Content-Type: text/plain; charset=UTF-8 X-Mailman-Approved-At: Sat, 21 Jun 2014 03:50:47 +0200 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: 77 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1403315448 news.xs4all.nl 2862 [2001:888:2000:d::a6]:40343 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:73475 Read this: https://docs.python.org/3.4/tutorial/floatingpoint.html On Sat, Jun 21, 2014 at 9:57 AM, FraserL wrote: > I think I found a strange bug in python 3.4.1, > > fresh install of > > https://www.python.org/ftp/python/3.4.1/python-3.4.1.amd64.msi > > and a fresh install of > https://www.python.org/ftp/python/2.7.7/python-2.7.7.amd64.msi > to compare it to. > > #test code > z = 0.01 > p = 0.0 > for x, y in enumerate(range(1, 20)): > p += z > print(p) > #end > > > 3.4.1 output: > > 0.01 > 0.02 > 0.03 > 0.04 > 0.05 > 0.060000000000000005 > 0.07 > 0.08 > 0.09 > 0.09999999999999999 > 0.10999999999999999 > 0.11999999999999998 > 0.12999999999999998 > 0.13999999999999999 > 0.15 > 0.16 > 0.17 > 0.18000000000000002 > 0.19000000000000003 > > > 2.7.7 output: > > 0.01 > 0.02 > 0.03 > 0.04 > 0.05 > 0.06 > 0.07 > 0.08 > 0.09 > 0.1 > 0.11 > 0.12 > 0.13 > 0.14 > 0.15 > 0.16 > 0.17 > 0.18 > 0.19 > > > I'm not hugely accustomed to Python, but this seems crazy to me. > -- > https://mail.python.org/mailman/listinfo/python-list -- INADA Naoki