Path: csiph.com!usenet.pasdenom.info!dedibox.gegeweb.org!gegeweb.eu!nntpfeed.proxad.net!proxad.net!feeder1-2.proxad.net!usenet-fr.net!nerim.net!novso.com!newsfeed.xs4all.nl!newsfeed4.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; 'python,': 0.02; 'syntax': 0.04; 'guido': 0.05; 'binary': 0.07; 'python:': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'similar,': 0.09; 'runs': 0.10; 'jan': 0.12; 'added.': 0.16; 'determines': 0.16; 'expression.': 0.16; 'notation,': 0.16; 'readability': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'reedy': 0.16; 'ternary': 0.16; 'wrote:': 0.18; 'example': 0.22; 'header:User-Agent:1': 0.23; 'looks': 0.24; 'equivalent': 0.26; 'second': 0.26; 'header:X-Complaints-To:1': 0.27; 'header:In- Reply-To:1': 0.27; 'compared': 0.30; 'statement': 0.30; 'strongly': 0.30; 'code': 0.31; 'perl': 0.31; 'piece': 0.31; 'community': 0.33; 'knowledge': 0.35; 'there': 0.35; 'i.e.': 0.36; 'opposed': 0.36; 'hi,': 0.36; 'two': 0.37; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'negative': 0.60; 'break': 0.61; 'received:173': 0.61; 'first': 0.61; 'kind': 0.63; 'believe': 0.68; 'reverse': 0.68; 'statement,': 0.68; 'superior': 0.69; 'opinions': 0.70; 'lack': 0.78; 'received:fios.verizon.net': 0.84; 'not:': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Terry Reedy Subject: Re: Postfix conditionals Date: Sun, 05 Jan 2014 21:58:46 -0500 References: <52C9BF95.5000006@gkayaalp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Gmane-NNTP-Posting-Host: pool-173-75-254-207.phlapa.fios.verizon.net User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 In-Reply-To: <52C9BF95.5000006@gkayaalp.com> 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: 45 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1388977145 news.xs4all.nl 2886 [2001:888:2000:d::a6]:41108 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:63263 On 1/5/2014 3:24 PM, G=C3=B6ktu=C4=9F Kayaalp wrote: > Hi, > > AFAIK, we do not have "postfix conditionals" in Python, i.e. a conditio= n > appended to a > statement, which determines whether the statement runs or not: > > py> for i in [False]: > ... break if not i > > The above piece of code is equivalent to this in Python: > > py> for i in [False]: > ... if not i > ... break > > I believe that the first example is superior to the second example when= > the two is compared > for readability and intuitiveness. We already have a ternary statement= 'conditional expression', which happens to be a ternary as opposed to=20 binary expression. > that looks similar, > > py> print('hi') if True else None > > so I reckon there would be no breakage in old code if this kind of > syntax was added. Ruby has > this, and AFAIK Perl also does. > > I lack the knowledge of whether the community has opinions on this kind= > of notation, In general, negative on pure duplication. Guido has said he strongly=20 dislikes the perl reverse if. --=20 Terry Jan Reedy