Path: csiph.com!usenet.pasdenom.info!news.albasani.net!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 0.002 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'languages,': 0.04; 'say,': 0.05; 'subject:Python': 0.06; 'affected': 0.07; 'dan': 0.09; 'happen,': 0.09; 'python': 0.11; 'bug': 0.12; 'caching': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'higher-level': 0.16; 'merely': 0.16; 'retrieving': 0.16; 'wrote:': 0.18; 'code.': 0.18; '(where': 0.19; 'properly': 0.19; 'things.': 0.19; 'memory': 0.22; 'python?': 0.22; 'print': 0.22; "shouldn't": 0.24; 'subject:problem': 0.24; 'mon,': 0.24; 'source': 0.25; 'header:In-Reply-To:1': 0.27; 'appear': 0.29; 'tim': 0.29; "doesn't": 0.30; 'message-id:@mail.gmail.com': 0.30; 'code': 0.31; 'critical': 0.32; 'languages': 0.32; 'bugs': 0.33; 'could': 0.34; 'subject:with': 0.35; 'common': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'aside': 0.39; 'to:addr:python.org': 0.39; 'how': 0.40; 'days': 0.60; 'skip:u 10': 0.60; 'most': 0.60; 'affect': 0.61; 'subject:The': 0.64; 'increase': 0.74; 'protect': 0.79; '2013': 0.98 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:to :content-type; bh=eA6xOxtAcdCQL58y4QpQqYaolIl2sn9uvkVsDkAc2SU=; b=erfTqkmu6i1TFFGd+/eTU5FRi7LAR2OmH4Bh4MwHcU+JL2vz5cQ9F1oDbQOZN/lT5Z 1zQp06w64Lxlt3R9qwlye6S065XulVccrKZ8pzP/qqUmzsXsIfRgMcW2nPiaAxSKeToH HKZZHMw2Prd4Rv6fjTF64+WI+zpC+7K5b8YJsywc8lJMnZohvWM9twdQnTYXdnX2f2KM 9NaafkTu6BXFaFXA2RKqz2AUcOk86Xf0+zlHnFShVO0Gc2iNWObeafoCeQ2TcDKi3e8I ogvwFHSaa2kFKqTKMKsT7QwE52o27hI0I0zvU6doLZK+ekwhigUFQOtA+DfAxIra8KtD auaA== MIME-Version: 1.0 X-Received: by 10.220.109.66 with SMTP id i2mr16200580vcp.51.1370235953222; Sun, 02 Jun 2013 22:05:53 -0700 (PDT) In-Reply-To: References: <687dea63-84da-4c45-9366-cb5a10665d1f@googlegroups.com> Date: Mon, 3 Jun 2013 15:05:53 +1000 Subject: Re: Python Heisenbugs? (was: Re: PyWart: The problem with "print") From: Chris Angelico To: python-list@python.org 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: 17 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1370235962 news.xs4all.nl 15864 [2001:888:2000:d::a6]:33141 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:46765 On Mon, Jun 3, 2013 at 2:34 PM, Dan Sommers wrote: > On Mon, 03 Jun 2013 13:37:27 +1000, Tim Delaney wrote: > >> With the increase in use of higher-level languages, these days >> Heisenbugs most often appear with multithreaded code that doesn't >> properly protect critical sections, but as you say, with lower-level >> languages uninitialised memory is a common source of them. > > Aside from an I/O caching bug directly affected by calling print or > somefile.write (where somefile is stdout), how else could I create a > Heisenbug in pure Python? If you have a @property, merely retrieving it could affect things. It shouldn't happen, but bugs can be anywhere. Basically, ANY Python code can trigger ANY Python code. ChrisA