Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.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 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'raises': 0.07; 'python': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:into': 0.09; 'subject:method': 0.09; 'utf8': 0.09; 'cc:addr:python-list': 0.10; 'subject:python': 0.11; 'extension': 0.13; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'subject: \n ': 0.16; 'subject:class': 0.16; 'wed,': 0.16; 'wrote:': 0.17; 'bytes': 0.17; 'instance': 0.17; 'refers': 0.17; 'unicode': 0.17; 'tests': 0.18; 'code,': 0.18; 'feb': 0.19; 'back.': 0.22; 'subject:problem': 0.22; 'cc:2**0': 0.23; 'class.': 0.23; "python's": 0.23; 'cc:no real name:2**0': 0.24; 'feature': 0.24; 'cc:addr:python.org': 0.25; 'header:In-Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.28; 'chris': 0.28; 'cpu': 0.29; 'question:': 0.29; 'function': 0.30; 'code': 0.31; 'purposes,': 0.33; 'to:addr:python-list': 0.33; 'times.': 0.33; 'pm,': 0.35; "won't": 0.35; 'something': 0.35; 'received:org': 0.36; 'really': 0.36; 'method': 0.36; 'does': 0.37; 'subject:: ': 0.38; 'fact': 0.38; 'sure': 0.38; 'performance': 0.39; 'to:addr:python.org': 0.39; 'takes': 0.39; 'called': 0.39; 'little': 0.39; 'header:Received:5': 0.40; 'think': 0.40; 'your': 0.60; 'easy': 0.60; 'between': 0.63; 'here': 0.65; 'god': 0.66; 'obvious': 0.71; 'saving': 0.72; 'goal': 0.74; 'received:109': 0.74; '2013': 0.84; 'benchmark': 0.84; 'sfxlen:4': 0.84; 'pfxlen:big': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Robin Becker Subject: Re: python 3 problem: how to convert an extension method into a class Method Date: Wed, 27 Feb 2013 11:11:08 +0000 References: <512CEF0C.3020906@chamonix.reportlab.co.uk> <512DE1AB.7000100@chamonix.reportlab.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: python-list@python.org X-Gmane-NNTP-Posting-Host: 109.174.168.73 User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130215 Thunderbird/17.0.3 In-Reply-To: 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: 29 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1361963479 news.xs4all.nl 6878 [2001:888:2000:d::a6]:50405 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:40051 On 27/02/2013 10:49, Chris Angelico wrote: > On Wed, Feb 27, 2013 at 9:36 PM, Robin Becker wrote: >> However, in my case the method takes >> >> >> >> py C >> utf8 bytes 50 20 usec >> unicode 39 15 >> >> here py refers to a native python method and C to the extension method >> after adding to the class. Both are called via an instance of the class. > > Which raises the obvious question: Does it even matter? Will the > saving of a few microseconds really make a difference? Python's best > feature is its clarity of code, not its blazing performance; its > performance goal is "fast enough", and for many MANY purposes, you > won't be able to tell the difference between that and "awesome". Don't > sacrifice your code's clarity to the little tin god of efficiency > until you're sure you actually get something back. > > ChrisA > in fact this is the stringWidth function and it's used thousands of times. I think when we did benchmark tests it came out as 1 or 2 as a cpu hog. Since it's comparatively easy to code it's an obvious choice to move to C. -- Robin Becker