Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!feeder.news-service.com!newsfeed.xs4all.nl!newsfeed6.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 0.033 X-Spam-Evidence: '*H*': 0.93; '*S*': 0.00; 'behavior.': 0.07; 'recipe': 0.07; 'python': 0.07; 'url:activestate': 0.09; 'pm,': 0.11; 'url:code': 0.11; 'wrote:': 0.14; 'furman': 0.16; 'seems': 0.21; 'header:In-Reply-To:1': 0.22; 'thu,': 0.22; 'posted': 0.22; 'java': 0.24; 'received:209.85.220': 0.26; 'instead': 0.26; 'object': 0.27; 'message-id:@mail.gmail.com': 0.28; 'class': 0.29; 'implement': 0.30; 'model': 0.31; 'carl': 0.31; 'engineering': 0.31; 'perhaps': 0.32; 'called': 0.32; 'to:addr:python-list': 0.32; 'another': 0.32; '(for': 0.33; 'using': 0.34; 'getting': 0.36; 'some': 0.37; 'it?': 0.37; 'received:209.85': 0.37; 'apr': 0.38; 'thursday,': 0.38; 'received:google.com': 0.38; 'pretty': 0.38; 'software': 0.38; 'used': 0.38; 'comments': 0.39; 'to:addr:python.org': 0.39; 'received:209': 0.39; "it's": 0.40; 'header:Received:5': 0.40; 'owns': 0.60; '2011': 0.62; 'upon': 0.63; 'concept': 0.73; 'composition': 0.84; 'rediscovered': 0.84; 'inheritance,': 0.91 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type:content-transfer-encoding; bh=rVJMwNgo6F6iYDXfv9Rd5Ar/RwtN4mbL+M80eGeHV8o=; b=rtYVmbv3tF+W2U3BlDZIXLn6PUIK3qYw6V2CObNzTPp9jxQBHlkdRtAYDWSvox3iCi 0jUF4Il7vCp4NyBBhy1G+SGBNO5abmSI2PwGuzo9aQTlolWQBg2vWf62wSEH64bMY17T JZMZCFjSbgtDQ7zUApQJdyk5qQA4ECnj0GrHU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=PMhUr56GBzSOXIheSAiptn9E4QN+P2zzhWonIkSPEmB8XLRtGYGyz/Cj/ITNe9sdwP 262QhaNxRq0CBohaSuVGsg2LZezGmAmsvOvzVhcTuME9+Ryh7g5pyklvazE081rXOxZG th9cVLXI9Fif8U8szUdS/BXN10Ix71k2CQqoI= MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 28 Apr 2011 20:58:57 -0700 Subject: Re: Composition instead of inheritance From: Dan Stromberg To: Python Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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: 21 NNTP-Posting-Host: 82.94.164.166 X-Trace: 1304049540 news.xs4all.nl 41102 [::ffff:82.94.164.166]:35125 X-Complaints-To: abuse@xs4all.nl Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:4293 On Thu, Apr 28, 2011 at 3:35 PM, Carl Banks wrot= e: > On Thursday, April 28, 2011 10:15:02 AM UTC-7, Ethan Furman wrote: >> For anybody interested in composition instead of multiple inheritance, I >> have posted this recipe on ActiveState (for python 2.6/7, not 3.x): >> >> http://code.activestate.com/recipes/577658-composition-of-classes-instea= d-of-multiple-inherit/ >> >> Comments welcome! > > That's not what we mean by composition. =A0Composition is when one object= calls upon another object that it owns to implement some of its behavior. = =A0Often used to model a part/whole relationship, hence the name. It's a pretty old idea, that seems to be getting revived in a big way all of a sudden. Perhaps the Java people just rediscovered it? In a Software Engineering class using Ada, the teacher called it "Structural Inclusion", and of course it was an important concept in Ada, because Ada had no inheritance. This was in 1989-1990.