Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!bcyclone02.am1.xlned.com!bcyclone02.am1.xlned.com!newsfeed.xs4all.nl!newsfeed1.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 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'url:pypi': 0.03; 'from:addr:yahoo.co.uk': 0.04; 'args': 0.07; 'subject:code': 0.07; 'dan': 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; 'worse': 0.09; 'def': 0.12; 'language.': 0.14; 'chunks': 0.16; 'it;': 0.16; 'iterates': 0.16; 'itertools': 0.16; 'itself,': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'recipe': 0.16; 'work."': 0.16; 'weird': 0.16; 'language': 0.16; 'wrote:': 0.18; 'wed,': 0.18; '(the': 0.22; '>>>': 0.22; 'header:User-Agent:1': 0.23; "i've": 0.25; 'header:X-Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'function': 0.29; 'url:bugs': 0.29; 'points': 0.29; 'along': 0.30; "i'm": 0.30; 'code': 0.31; 'relies': 0.31; 'says': 0.33; 'url:python': 0.33; 'but': 0.35; 'subject:?': 0.36; 'url:org': 0.36; 'detail': 0.37; 'url:library': 0.38; 'skip:[ 10': 0.38; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'according': 0.40; 'ian': 0.60; 'url:3': 0.61; 'guarantee': 0.63; 'our': 0.64; 'zip': 0.64; 'charset:windows-1252': 0.65; 'here': 0.66; 'mar': 0.68; 'fact,': 0.69; 'url:4': 0.69; 'opinions': 0.70; 'article': 0.77; '"it': 0.84; '2015': 0.84; 'abc': 0.84; 'guaranteed.': 0.84; 'url:posts': 0.84; 'sitting': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Mark Lawrence Subject: Re: Brilliant or insane code? Date: Wed, 18 Mar 2015 15:20:12 +0000 References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: host-92-24-220-174.ppp.as43234.net User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.19 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: 41 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1426692040 news.xs4all.nl 2856 [2001:888:2000:d::a6]:45680 X-Complaints-To: abuse@xs4all.nl X-Received-Bytes: 4784 X-Received-Body-CRC: 2903072587 Xref: csiph.com comp.lang.python:87684 On 18/03/2015 14:59, Ian Kelly wrote: > On Tue, Mar 17, 2015 at 7:14 PM, Dan Sommers wrote: >> On Wed, 18 Mar 2015 00:35:42 +0000, Mark Lawrence wrote: >> >>> I've just come across this >>> http://www.stavros.io/posts/brilliant-or-insane-code/ as a result of >>> this http://bugs.python.org/issue23695 >>> >>> Any and all opinions welcomed, I'm chickening out and sitting firmly >>> on the fence. >> >> According to the article itself, "it relies in an implementation detail >> (the order the zip function iterates over the arrays) to work." Then >> again, the article also points to the official docs that says that this >> implementation detail is guaranteed. >> >> So it's no worse than depending on some weird but *documented* corner of >> the IEEE-754 or POSIX spec. > > In fact, this is also a code recipe found in the itertools > documentation. The official docs don't just guarantee it; they > *recommend* it. > > def grouper(iterable, n, fillvalue=None): > "Collect data into fixed-length chunks or blocks" > # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx" > args = [iter(iterable)] * n > return zip_longest(*args, fillvalue=fillvalue) > > https://docs.python.org/3.4/library/itertools.html > Which is available here https://pypi.python.org/pypi/more-itertools along with many other goodies. -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence