Path: csiph.com!au2pb.net!feeder.erje.net!1.eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed8.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 0.031 X-Spam-Evidence: '*H*': 0.94; '*S*': 0.00; 'cc:addr:python-list': 0.09; 'python': 0.10; '(but': 0.15; 'thu,': 0.15; 'cleaner': 0.16; 'expression.': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'lambda': 0.16; 'subject:class': 0.16; 'wrote:': 0.16; '2015': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; 'aug': 0.20; 'explicit': 0.22; 'am,': 0.23; 'header:In-Reply- To:1': 0.24; 'message-id:@mail.gmail.com': 0.27; '13,': 0.29; 'probably': 0.31; 'class': 0.33; 'list': 0.34; 'received:google.com': 0.35; 'comment': 0.35; 'but': 0.36; 'subject:: ': 0.37; 'why': 0.39; 'rather': 0.39; 'per': 0.62; 'more': 0.63; 'chrisa': 0.84; 'otten': 0.84; 'to:none': 0.91; 'leak': 0.91; 'favour': 0.93 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=7RwBRYxy2OjLCuLeODTHkXccDgSnI2GgIvwb7U4jgPc=; b=vPHNZ3VpAev2+ujGGERG70g31TCWpJDQgM+j0L9UKVTJMs8WwiPY2gdUndzA6W9Sjd kNDxciyaNTPHPZkdqPwvi/cZqMoCzKnL2nB2w2NRGnfaC3485jeNImRoWDYz8z5TsoM7 RVBNDSgXoDZs7AOHyFPXQZhoDDCNbnZC76oqyHWsb2olvwXl/pv2UP8LhJ/3X3IpLD1v C/0SaZ9B4+rYEQgxxgDbJkmi8R7tsKVnFCOxpItEa2/4yKRk1YP+rdnHszo7S3zjcqVB rud8i5WuPVkn/8tAgTouocaq6DskiMf37YbVoODHDQ3kkq7a8dlmQO6Kqa+qKyB8MmJN JG9w== MIME-Version: 1.0 X-Received: by 10.107.12.166 with SMTP id 38mr21608200iom.157.1439395150900; Wed, 12 Aug 2015 08:59:10 -0700 (PDT) In-Reply-To: References: <85fv3oj2y6.fsf@benfinney.id.au> Date: Thu, 13 Aug 2015 01:59:10 +1000 Subject: Re: Ensure unwanted names removed in class definition From: Chris Angelico Cc: "python-list@python.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ 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: 1439395153 news.xs4all.nl 2849 [2001:888:2000:d::a6]:35562 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:95287 On Thu, Aug 13, 2015 at 1:39 AM, Peter Otten <__peter__@web.de> wrote: > But I would probably use a generator expression. These don't leak names: > > Python 2.7.6 (default, Jun 22 2015, 17:58:13) > [GCC 4.8.2] on linux2 > Type "help", "copyright", "credits" or "license" for more information. >>>> class Parrot: > ... a = [per for per in "abc"] > ... b = list(trans for trans in "def") > ... Ooh neat trick! Much cleaner than the explicit lambda that I suggested. Withdrawing my recommendation in favour of this (but with an explanatory comment explaining why list(genexp) is used rather than a list comp). ChrisA