Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Mark Lawrence Newsgroups: comp.lang.python Subject: Re: Pyhon 2.x or 3.x, which is faster? Date: Tue, 8 Mar 2016 02:45:21 +0000 Lines: 40 Message-ID: References: <87d1r6iltx.fsf@elektro.pacujo.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.uni-berlin.de Z9eqb/q1vy6MdCet13yi+QxnhGINYMDeMYKw+jlCxRBw== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'python,': 0.02; 'from:addr:yahoo.co.uk': 0.05; 'startup': 0.05; '0.1': 0.09; 'cached': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:which': 0.09; 'python': 0.10; 'file,': 0.15; '0.2': 0.16; 'at,': 0.16; 'disk.': 0.16; 'measuring': 0.16; 'received:80.91.229.3': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'seconds,': 0.16; 'seconds.': 0.16; 'useless.': 0.16; 'wrote:': 0.16; 'figures': 0.18; 'python?': 0.18; 'language': 0.19; '>>>': 0.20; 'load': 0.20; 'do.': 0.22; 'lawrence': 0.22; 'second': 0.24; 'header:In-Reply-To:1': 0.24; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'not.': 0.27; 'disk': 0.27; 'code': 0.30; 'compared': 0.30; "i'd": 0.31; 'probably': 0.31; 'language.': 0.32; 'file': 0.34; 'files,': 0.35; 'but': 0.36; 'faster': 0.36; 'to:addr:python-list': 0.36; 'subject:?': 0.36; 'subject:: ': 0.37; 'received:org': 0.37; 'difference': 0.38; 'why': 0.39; 'test': 0.39; 'does': 0.39; 'enough': 0.39; 'to:addr:python.org': 0.40; 'where': 0.40; 'mark': 0.40; 'your': 0.60; 'per': 0.62; 'charset:windows-1252': 0.62; 'making': 0.62; 'course': 0.62; 'more': 0.63; 'more.': 0.63; 'times': 0.63; 'our': 0.64; 'between': 0.65; '10000': 0.66; '100': 0.79; 'os?': 0.84; 'popular.': 0.84; 'pythonistas,': 0.84; 'reading,': 0.84 X-Injected-Via-Gmane: http://gmane.org/ X-Gmane-NNTP-Posting-Host: 80.234.129.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com comp.lang.python:104315 On 08/03/2016 01:47, BartC wrote: > On 08/03/2016 01:12, Mark Lawrence wrote: >> On 08/03/2016 01:00, BartC wrote: >>> >>> If your efforts manage to double the speed of reading file A, then >>> probably the reading file B is also going to be improved! In practice >>> you use a variety of files, but one at a time will do. >>> >> >> What is the difference in your timing when you first read the file, and >> then read it a second time when it's been cached by the OS? In other >> words, you are probably measuring more of the response time of the disk >> than the code that does the reading, hence making your figures useless. >> > > It's not going to be significant. My hard drive is going to read at, > what, 100MB per second? Probably more. > > One test file is 0.2MB. Load time is going to be negligible whether > cached or not. > > The Python timing for that file is around 20 seconds, time enough to > read 10000 copies from the disk. > > And a C program reads /and decodes/ the same file from the same disk in > between 0.1 and 0.2 seconds. > So how much of that time is Python startup time, compared to C which is effectively zero? Or are you suggesting that C code is always 100 times faster than Python? Of course I'd like to see you write C code 100 times faster than Python, but of course that's where Python shines, which is why it is so popular. -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence