Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!goblin3!goblin.stu.neva.ru!newsfeed3.funet.fi!newsfeeds.funet.fi!newsfeed1.swip.net!uio.no!news.tele.dk!news.tele.dk!small.news.tele.dk!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 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'from:addr:yahoo.co.uk': 0.04; 'string': 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; 'sake': 0.09; 'seemed': 0.09; 'style.': 0.09; 'subject:string': 0.09; 'url:activestate': 0.09; 'language.': 0.14; "%s'": 0.16; "'%s": 0.16; 'delimiter': 0.16; 'fine.': 0.16; 'iterable': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'roy': 0.16; 'string:': 0.16; 'syntax,': 0.16; 'subject:python': 0.16; 'language': 0.16; 'wrote:': 0.18; 'obviously': 0.18; 'variable': 0.18; 'written': 0.21; '(in': 0.22; 'header:User-Agent:1': 0.23; 'header:X -Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'generally': 0.29; 'url:code': 0.29; "doesn't": 0.30; 'change,': 0.30; 'compared': 0.30; 'moved': 0.30; 'said,': 0.30; "skip:' 10": 0.31; 'probably': 0.32; '(e.g.': 0.33; 'could': 0.34; 'something': 0.35; 'case,': 0.35; 'but': 0.35; 'there': 0.35; 'really': 0.36; 'doing': 0.36; 'two': 0.37; 'list': 0.37; 'performance': 0.37; 'being': 0.38; 'to:addr:python-list': 0.38; 'short': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; "you're": 0.61; 'first': 0.61; 'you.': 0.62; 'our': 0.64; 'pick': 0.64; 'places': 0.64; 'more': 0.64; 'charset:windows-1252': 0.65; 'smith': 0.68; 'article': 0.77; 'as:': 0.81; 'complexity': 0.84; 'penalty': 0.84; 'received:89': 0.85 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Mark Lawrence Subject: Re: python string, best way to concat Date: Thu, 28 Aug 2014 15:48:48 +0100 References: <55bab2a0-e0bc-4398-90b4-c9937498f5d8@googlegroups.com> <63bdccb4-9e34-4e40-b07d-14342e21815f@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: host-89-240-167-224.as13285.net User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.0 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: 40 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1409237343 news.xs4all.nl 2897 [2001:888:2000:d::a6]:52373 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:77213 On 28/08/2014 13:08, Roy Smith wrote: > In article <63bdccb4-9e34-4e40-b07d-14342e21815f@googlegroups.com>, > peter wrote: > >> I used to struggle with the concept of ''.join(('hello ','world')) - it >> seemed so convoluted compared with the intuitive 'hello '+'world', and I >> could never remember the syntax. Also, for the strings I was generally using >> the performance penalty was infinitesimal, so I was just adding complexity >> for the sake of the abstract concept of a more 'pythonic' style. >> >> Obviously this isn't going to change, but for concatenating short strings a >> and b is there any practical reason to avoid a+b? > > For places where performance doesn't matter, string addition is just > fine. The computer works for you. If you're working for the computer, > you're doing something wrong. > > That being said, join is typically used where you have a variable number > of strings in some iterable (e.g. a list of strings). For exactly two > strings, I would have probably written this as: > > '%s %s' % (string1, string2) > > and if I really wanted to use the join syntax, I would have moved the > delimiter (in this case, a space), into the first string: > > ' '.join([string1, string2]) > > Be aware of the various ways, then pick the one that works for you. > Which reminds me of http://code.activestate.com/recipes/577845-format_iter-easy-formatting-of-arbitrary-iterables/ -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence