Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.mixmin.net!news2.arglkargh.de!news.albasani.net!newsfeed.freenet.ag!news2.euro.net!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 0.002 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'classes.': 0.05; 'all?': 0.09; 'overridden': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'am,': 0.12; 'class,': 0.15; 'attribute,': 0.16; 'creation.': 0.16; 'mro': 0.16; 'new-style': 0.16; 'received:dip.t-dialin.net': 0.16; 'received:t-dialin.net': 0.16; 'wrote:': 0.18; '>>>': 0.18; 'from:addr:web.de': 0.23; "shouldn't": 0.23; 'function': 0.27; 'class': 0.29; '(and': 0.30; 'kelly': 0.30; 'sun,': 0.30; 'url:library': 0.31; 'cases': 0.32; 'idea': 0.32; 'there': 0.33; 'header:User-Agent:1': 0.33; 'header:X-Complaints-To:1': 0.34; 'stores': 0.34; 'probably': 0.35; 'to:addr:python-list': 0.35; 'url:python': 0.35; 'received:org': 0.36; 'but': 0.37; 'using': 0.37; 'url:org': 0.39; 'cannot': 0.39; 'to:addr:python.org': 0.40; "you'll": 0.61; 'provided': 0.62; '11,': 0.68; 'directly.': 0.68 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Peter Otten <__peter__@web.de> Subject: Re: newb __init__ inheritance Date: Sun, 11 Mar 2012 13:12:25 +0100 Organization: None References: <1c6db866-6fa3-4de5-96de-51d6720a1300@x17g2000yqj.googlegroups.com> <2feb13ca-f83b-4843-995f-ee77e7505ecd@db5g2000vbb.googlegroups.com> <18769501.3541.1331463388634.JavaMail.geo-discussion-forums@ynkz21> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit X-Gmane-NNTP-Posting-Host: p5084a06c.dip.t-dialin.net User-Agent: KNode/4.7.3 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 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: 19 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1331467945 news.xs4all.nl 6981 [2001:888:2000:d::a6]:50043 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:21493 Ian Kelly wrote: > On Sun, Mar 11, 2012 at 5:40 AM, Ian Kelly wrote: >>> 2. Is the mro function available only on python3? >> >> No, but it is available only on new-style classes. If you try it on a >> classic class, you'll get an AttributeError. > > And by the way, you probably shouldn't call the mro method directly. > That method is provided so that it can be overridden in order to > customize the MRO at class creation. The proper (and faster) way to > look up the MRO for a class is using the __mro__ attribute, which > stores the result of the mro method when the class is initialized. > > http://docs.python.org/library/stdtypes.html?highlight=mro#class.__mro__ Is it a good idea to use mro() or __mro__ at all? Are there common use cases that cannot be addressed with super()?