Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!rt.uk.eu.org!newsfeed.xs4all.nl!newsfeed1.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 0.004 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'compact': 0.09; 'subject:design': 0.09; 'python': 0.11; 'bonus,': 0.16; 'burak': 0.16; 'elt': 0.16; 'from:addr:arskom.com.tr': 0.16; 'from:addr:burak.arslan': 0.16; 'from:name:burak arslan': 0.16; 'iterable,': 0.16; 'message-id:@arskom.com.tr': 0.16; 'received:arskomhosting.com': 0.16; 'subject:Language': 0.16; 'wrote:': 0.18; 'header:User-Agent:1': 0.23; 'looks': 0.24; 'this:': 0.26; 'header:In-Reply-To:1': 0.27; 'assert': 0.31; "d'aprano": 0.31; 'steven': 0.31; 'but': 0.35; 'to:addr:python- list': 0.38; 'sure': 0.39; 'to:addr:python.org': 0.39; 'first': 0.61; 'mistakes,': 0.84 Date: Wed, 11 Sep 2013 13:38:06 +0300 From: Burak Arslan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130711 Thunderbird/17.0.7 MIME-Version: 1.0 To: python-list@python.org Subject: Re: Language design References: <522eb795$0$29999$c3e8da3$5496439d@news.astraweb.com> In-Reply-To: <522eb795$0$29999$c3e8da3$5496439d@news.astraweb.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit 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: 16 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1378896446 news.xs4all.nl 15896 [2001:888:2000:d::a6]:46951 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:53949 On 09/10/13 09:09, Steven D'Aprano wrote: > What design mistakes, traps or gotchas do you think Python has? My favourite gotcha is this: elt, = elts It's a nice and compact way to do both: assert len(elts) == 0 elt = elts[0] but it sure looks strange at first sight. As a bonus, it works on any iterable, not just ones that support __getitem__. burak