Path: csiph.com!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!newsfeed.xs4all.nl!newsfeed2a.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 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'else:': 0.03; 'cpython': 0.05; 'subject:Python': 0.06; 'extent': 0.07; 'stops': 0.07; '2to3': 0.09; 'migration': 0.09; 'pep': 0.09; 'rewrite': 0.09; 'subject:language': 0.09; 'cc:addr:python-list': 0.11; 'python': 0.11; 'language,': 0.12; '2.7': 0.14; 'language.': 0.14; 'changes': 0.15; '3.3,': 0.16; 'exploits': 0.16; 'fork': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'interpreter,': 0.16; 'patches': 0.16; 'simple.': 0.16; "someone's": 0.16; 'subject: \n ': 0.16; 'weigh': 0.16; 'folks': 0.16; 'sat,': 0.16; 'wrote:': 0.18; 'all,': 0.19; 'cc:addr:python.org': 0.22; '2.x': 0.24; 'driven': 0.24; 'versions': 0.24; 'cc:2**0': 0.24; 'header:In-Reply-To:1': 0.27; 'especially': 0.30; 'subject:list': 0.30; 'message- id:@mail.gmail.com': 0.30; '(which': 0.31; 'towards': 0.31; 'maintaining': 0.32; 'python.org': 0.32; 'running': 0.33; 'something': 0.35; 'test': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'there': 0.35; 'version': 0.36; 'too': 0.37; 'hat': 0.38; 'whatever': 0.38; 'pm,': 0.38; 'that,': 0.38; 'anything': 0.39; 'new': 0.61; 'companies': 0.62; 'more': 0.64; 'different': 0.65; 'risk': 0.72; 'subject:this': 0.83; 'conservative': 0.84; 'job;': 0.84; 'move.': 0.84; 'route': 0.84; 'migrating': 0.91; '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=w0YDCQI7RM6y/nFrS5k8IqhD6SXArBuJ/GX6FJU7WjI=; b=rnLWxLBApmHjEmwfsY3RcrHDct/qklclLb9GkZBLX6VEjfu0uijDjMnE1hl0DZ/USw PkNl8kOtH50KR/NIFNK44YcGDsVRn9JbMpGi62wSQXQ8QADtXuIy/ZkPZDZtc3JoSl0Y ndc2xJcu0pdkpNVBoBEd8Z0LeWUpCmkzmFtKh4AbziaGx8T+BHYdgf36Xkko4HTcMRGm flgfRmYJy5cOd8MwSvlJ21tSOV9XmcjziLGrc7r+EKaNXX4TwXm+7sS7Amv6nmXn0UAa i2AWpSa764puhy0h/+X4A96FCvjavihiMwpd2adT7Q2xh1s0MAb6X93wtqmMlVj/NZDg lP5A== MIME-Version: 1.0 X-Received: by 10.68.239.137 with SMTP id vs9mr19091795pbc.84.1396672825142; Fri, 04 Apr 2014 21:40:25 -0700 (PDT) In-Reply-To: References: <9daf0806-02de-4447-964c-c8f8953c23e5@googlegroups.com> <53364327$0$29994$c3e8da3$5496439d@news.astraweb.com> <53365F55.2040302@gmail.com> <533836c4$0$29994$c3e8da3$5496439d@news.astraweb.com> <533F2D0F.2080806@gmail.com> <533F3796.1000807@gmail.com> Date: Sat, 5 Apr 2014 15:40:24 +1100 Subject: Re: Explanation of this Python language feature? [x for x in x for x in x] (to flatten a nested list) 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: 21 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1396672827 news.xs4all.nl 2853 [2001:888:2000:d::a6]:38766 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:69707 On Sat, Apr 5, 2014 at 3:10 PM, Mark H Harris wrote: > we don't want folks to be driven away from Cpython as a language, and we > don't want them to fork the Cpython interpreter, so we'll take a very casual > and methodically conservative approach to nudging people towards a Cpython3 > migration route If it's too much work to make the changes to move something from Python 2.7 to Python 3.3, it's *definitely* too much work to rewrite it in a different language. There would have to be some strong other reason for shifting, especially since there's a 2to3 but not a PytoRuby. And forking is a pretty huge job; someone's gotta maintain it. What's more likely is that, once python.org stops maintaining Python 2.x at all, people will just stay on 2.7.9 or whatever the last version is, without any bugfixes. Companies like Red Hat will be looking at security patches (which is what PEP 466 is all about), but only to the extent that they have people willing to put in the work to make and test them. After that, it'll be like running old versions of anything else: you weigh the cost of migrating to the new version against the risk of exploits if you don't move. It's that simple. ChrisA