Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed1.news.xs4all.nl!xs4all!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; 'syntax': 0.04; 'argument': 0.05; 'subject:Python': 0.06; 'explicit': 0.07; '"if': 0.09; 'subject:using': 0.09; 'cc:addr:python-list': 0.11; '*you*': 0.16; '8:40': 0.16; 'abusing': 0.16; 'empty.': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'recognise': 0.16; 'skips': 0.16; 'true:': 0.16; 'wrote:': 0.18; 'code.': 0.18; 'starts': 0.20; 'cc:addr:python.org': 0.22; 'mon,': 0.24; 'cc:2**0': 0.24; 'header:In-Reply-To:1': 0.27; 'dec': 0.30; 'message-id:@mail.gmail.com': 0.30; "i'm": 0.30; 'too.': 0.31; 'changed.': 0.31; "d'aprano": 0.31; 'steven': 0.31; 'sense': 0.34; 'but': 0.35; 'received:google.com': 0.35; 'version': 0.36; 'clear': 0.37; 'list,': 0.38; 'pm,': 0.38; 'course': 0.61; 'first': 0.61; '(generic': 0.84; 'to:none': 0.92 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=mK2zOlf1aEtLbwRtjmiaQU40DMP1qVhWiRYRvvR1Zk4=; b=GPmXDssoVAoiuViCG+/6EoXhl3z6F7KJ4/JcX6F2nwfT5aN0yZ0tOhlbeuC2Gxahg1 AsXfpgjQZGH4t9cii+1v68rnbulBUEnIB1XM0cp9Iva6ptR0E4FFD6F9kuoYkzCN+ylj DFnHm99QirumXsJQsMmiptcepEnjaB8m5/5Xuxi3r91QLXuJrZwKGBHWQx2LUC+rd2Rm J+Rc5baSwAHqHVFyx9wgNJoia2kHebA1kmdY+s79cDNTG7Wk0VESmuEfItzMbIn1VqbU kNoyg83XhPjUB4Uc3rdix8ve6+XjtKBhobtZ6hcjyQq151Z9MGgE/riaF8E5i8EwO8Z6 qTAg== MIME-Version: 1.0 X-Received: by 10.42.94.14 with SMTP id z14mr17542503icm.59.1418032244518; Mon, 08 Dec 2014 01:50:44 -0800 (PST) In-Reply-To: <5485721c$0$2817$c3e8da3$76491128@news.astraweb.com> References: <004e01d01173$e1641c10$a42c5430$@gmail.com> <5484e3d8$0$13013$c3e8da3$5496439d@news.astraweb.com> <5485721c$0$2817$c3e8da3$76491128@news.astraweb.com> Date: Mon, 8 Dec 2014 20:50:44 +1100 Subject: Re: Python Iterables struggling using map() built-in From: Chris Angelico Cc: "python-list@python.org" Content-Type: text/plain; charset=UTF-8 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: 17 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1418032252 news.xs4all.nl 2835 [2001:888:2000:d::a6]:57443 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:82118 On Mon, Dec 8, 2014 at 8:40 PM, Steven D'Aprano wrote: > The first version is explicit and clear too. I'm sorry to say this, but > it is true: if you (generic you) don't recognise that > > while iters: > ... > > > skips the while block if iters is an empty list, then *you* have a > problem, not the code. Of course it skips the body if iters starts out empty. The argument is whether or not it makes sense to use this to mean "if iters: while True:" because iters will never be changed. Is it abusing syntax or a valid way to spell that condition? ChrisA