Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!newsfeed.xs4all.nl!newsfeed6.news.xs4all.nl!xs4all!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; 'mrab': 0.04; 'converting': 0.15; "(i'll": 0.16; '-tkc': 0.16; 'bit.': 0.16; 'comma': 0.16; 'comma,': 0.16; 'element,': 0.16; 'elements,': 0.16; 'from:addr:python.list': 0.16; 'from:addr:tim.thechases.com': 0.16; 'from:name:tim chase': 0.16; 'iterator': 0.16; 'iterators,': 0.16; 'message-id:@tim.thechases.com': 0.16; 'received:70.251': 0.16; 'received:dsl.rcsntx.swbell.net': 0.16; 'received:rcsntx.swbell.net': 0.16; 'received:swbell.net': 0.16; 'roy': 0.16; 'settle': 0.16; 'cc:addr:python-list': 0.16; 'wrote:': 0.18; '>>>': 0.18; 'string,': 0.18; 'memory': 0.21; 'header:In-Reply-To:1': 0.22; 'cc:2**0': 0.24; 'code': 0.25; '(in': 0.26; 'bit': 0.28; 'odd': 0.29; 'cc:addr:python.org': 0.29; 'handling': 0.30; "i've": 0.31; 'source': 0.31; 'cases': 0.32; 'list': 0.32; 'pretty': 0.32; 'header:User-Agent:1': 0.33; 'instead': 0.33; 'there': 0.33; 'it?': 0.33; 'running': 0.35; 'especially': 0.35; 'subject:How': 0.35; 'beginning': 0.36; 'conjunction': 0.37; 'list,': 0.37; "there's": 0.37; 'cases,': 0.38; 'some': 0.38; 'why': 0.39; "it's": 0.40; 'more': 0.61; 'special': 0.68; 'suggests.': 0.84 Date: Thu, 15 Dec 2011 12:51:49 -0600 From: Tim Chase User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.24) Gecko/20111120 Icedove/3.1.16 MIME-Version: 1.0 To: Ethan Furman Subject: Re: How to generate "a, b, c, and d"? References: <9393353.282.1323967703697.JavaMail.geo-discussion-forums@vbyc2> <4EEA35F8.4090502@tim.thechases.com> <4EEA3A47.5020106@stoneleaf.us> In-Reply-To: <4EEA3A47.5020106@stoneleaf.us> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - boston.accountservergroup.com X-AntiAbuse: Original Domain - python.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tim.thechases.com X-Source: X-Source-Args: X-Source-Dir: Cc: Python X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 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: 28 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1323975113 news.xs4all.nl 6989 [2001:888:2000:d::a6]:35902 X-Complaints-To: abuse@xs4all.nl Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:17305 On 12/15/11 12:19, Ethan Furman wrote: > Tim Chase wrote: >> On 12/15/11 10:48, Roy Smith wrote: >>> I've got a list, ['a', 'b', 'c', 'd']. I want to generate the string, >>> "a, b, c, and d" (I'll settle for no comma after 'c'). Is there some >>> standard way to do this, handling all the special cases? >> >> If you have a list, it's pretty easy as MRAB suggests. For arbitrary >> iterators, it's a bit more complex. Especially with the odd edge-case >> of 2 items where there's no comma before the conjunction (where>2 has >> the comma before the conjunction). If you were willing to forgo the >> Oxford comma, it would tidy up the code a bit. > > Why go through all that instead of just converting the iterator into a > list at the beginning of MRAB's solution and then running with it? For the fun/challenge? Because you have a REALLY big data source that you don't want to keep in memory (in addition the resulting string)? Yeah, for most non-pathological cases, it would make more sense to just make it a list and then deal with the 4 cases (no elements, one element, 2 elements, and >2 elements) individually. -tkc