Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!news.swapon.de!news.stack.nl!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!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; 'string.': 0.05; 'indices': 0.07; 'string': 0.09; 'false.': 0.09; 'lawrence': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; '11:09': 0.16; 'point!': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'slice,': 0.16; 'subject:bit': 0.16; 'exception': 0.16; 'index': 0.16; 'wrote:': 0.18; 'header :User-Agent:1': 0.23; "haven't": 0.24; 'header:X-Complaints-To:1': 0.27; 'am,': 0.29; 'character': 0.29; 'characters': 0.30; 'code': 0.31; 'extract': 0.31; 'run': 0.32; 'checking': 0.33; 'problem': 0.35; 'but': 0.35; 'there': 0.35; 'charset:us-ascii': 0.36; 'to:addr:python-list': 0.38; 'that,': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'problems.': 0.60; "you're": 0.61; "you'll": 0.62; "you've": 0.63; 'sample': 0.67; 'ethan': 0.84; 'furman': 0.84 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Neil Cerutti Subject: Re: A curious bit of code... Date: Thu, 13 Feb 2014 19:25:27 +0000 (UTC) Organization: Norwich University References: <4cc09129-43ee-4205-a24c-03f92b594abc@googlegroups.com> <52FD1B01.80200@stoneleaf.us> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: jackman.norwich.edu User-Agent: slrn/0.9.9p1/mm/ao (Win32) 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: 19 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1392319553 news.xs4all.nl 2849 [2001:888:2000:d::a6]:33218 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:66214 On 2014-02-13, Ethan Furman wrote: > On 02/13/2014 11:09 AM, Mark Lawrence wrote: >> All I can say is that if you're worried about the speed of a >> single line of code like the above then you've got problems. >> Having said that, I suspect that using an index to extract a >> single character has to be faster than using a slice, but I >> haven't run these through a profiler yet :) > > The problem with using indices in the code sample is that if > the string is 0 or 1 characters long you'll get an exception > instead of a False. There will be an exception only if it is zero-length. But good point! That's a pretty sneaky way to avoid checking for a zero-length string. Is it a popular idiom? -- Neil Cerutti