Path: csiph.com!usenet.pasdenom.info!goblin1!goblin2!goblin.stu.neva.ru!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 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'classes.': 0.07; 'before.': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subclass': 0.09; 'subject:2.7': 0.09; 'jan': 0.11; '2.7': 0.13; 'properly': 0.15; 'class)': 0.16; 'commented': 0.16; 'inst': 0.16; 'old-style': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'reedy': 0.16; 'subject:non': 0.16; 'wrote:': 0.16; 'of.': 0.18; '>>>': 0.20; 'changes': 0.20; 'fix': 0.21; '2.x': 0.22; 'class,': 0.22; 'object.': 0.22; 'pass': 0.22; 'needed.': 0.23; 'written': 0.24; 'header:In-Reply-To:1': 0.24; 'header:User-Agent:1': 0.26; 'example': 0.26; 'header:X -Complaints-To:1': 0.26; 'least': 0.27; 'run': 0.33; 'class': 0.33; 'raising': 0.33; 'steven': 0.33; 'file': 0.34; 'handle': 0.34; 'false': 0.35; 'instance': 0.35; 'knowledge': 0.35; 'needed': 0.36; 'lines': 0.36; 'to:addr:python-list': 0.36; 'subject:?': 0.36; 'pm,': 0.36; 'subject:: ': 0.37; 'expect': 0.37; 'received:org': 0.37; 'difference': 0.38; 'someone': 0.38; 'test': 0.39; 'sure': 0.39; 'subject:-': 0.39; 'to:addr:python.org': 0.40; 'some': 0.40; 'forget': 0.60; 'ever': 0.60; 'claim': 0.61; 'making': 0.62; 'face': 0.64; 'differences': 0.66; 'hand': 0.82; '2.7.': 0.84; 'answer:': 0.84; 'unnecessary,': 0.84; 'received:fios.verizon.net': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Terry Reedy Subject: Re: Should non-security 2.7 bugs be fixed? Date: Tue, 21 Jul 2015 01:14:48 -0400 References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: pool-98-114-97-173.phlapa.fios.verizon.net User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 In-Reply-To: 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: 41 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1437455717 news.xs4all.nl 2894 [2001:888:2000:d::a6]:58869 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:94271 On 7/19/2015 6:19 PM, Terry Reedy wrote: > I, and others, have already made some changes to eliminate differences > that are unnecessary, at least for 2.7 versus 3.3+ or now 3.4+. I just got smacked in the face by a difference I had not run into before. I added about 10 lines to a test file is a section that is identical in 2.7 and 3.4+. One line is self.assertEqual(type(obj), intended class) It failed in 2.7. Quiz: when is the type of an instance not the class that the instance is an instance of. (I expect Steven A. is raising his hand now.) Give up? Answer: When you write a class in 2.x without making it a subclass of object. >>> class Class(): pass >>> inst = Class() >>> type(inst) is Class False >>> type(inst) Since I do not remember how to fix the assert, and was not prepared to make the class, in a file other than the one tested, new-style, I just commented it out. This is an example of my claim that backports are best written by someone who is a current 2.x user with the particular 2.x knowledge needed. I am not sure I ever had all the knowledge needed to handle the backport properly and I now I would prefer to forget about old-style classes. -- Terry Jan Reedy