Path: csiph.com!usenet.pasdenom.info!gegeweb.org!newsfeed.kamp.net!newsfeed.kamp.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 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'python.': 0.02; 'classes,': 0.05; 'interpreter': 0.05; '"""': 0.07; 'definitions': 0.07; 'python3': 0.07; '"class"': 0.09; 'feature.': 0.09; 'objects:': 0.09; 'python': 0.11; 'distinct': 0.16; 'internally': 0.16; 'interpreter,': 0.16; 'mechanism.': 0.16; 'received:74.208.4.195': 0.16; 'subclass': 0.16; 'subject: \n ': 0.16; 'subject:OOP': 0.16; 'subject:object': 0.16; 'subject:possible': 0.16; 'subject:programming': 0.16; 'subject:type': 0.16; 'tried:': 0.16; 'typeerror:': 0.16; 'types,': 0.16; 'wrote:': 0.18; 'trying': 0.19; "python's": 0.19; 'user.': 0.19; 'written': 0.21; 'seems': 0.21; 'feb': 0.22; '>>>': 0.22; 'code,': 0.22; 'header:User-Agent:1': 0.23; 'versions': 0.24; 'class.': 0.26; 'pass': 0.26; 'subject:/': 0.26; 'supported': 0.26; 'header:In-Reply-To:1': 0.27; '"",': 0.31; "d'aprano": 0.31; 'steven': 0.31; 'file': 0.32; 'class': 0.32; 'url:python': 0.33; '(most': 0.33; 'entirely': 0.33; 'could': 0.34; 'classes': 0.35; 'no,': 0.35; 'but': 0.35; 'acceptable': 0.36; 'keyword': 0.36; 'url:org': 0.36; 'detail': 0.37; 'two': 0.37; 'starting': 0.37; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'recent': 0.39; 'to:addr:python.org': 0.39; 'future': 0.60; 'mentioned': 0.61; 'url:3': 0.61; 'simply': 0.61; "you're": 0.61; 'subject:The': 0.64; 'more': 0.64; 'here': 0.66; 'received:74.208': 0.68; 'gotten': 0.74; '100%': 0.77; 'pardon': 0.84; 'url:datamodel': 0.84; 'url:reference': 0.84; '2013,': 0.91; 'hopes': 0.91 Date: Mon, 15 Apr 2013 17:13:44 -0400 From: Dave Angel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: python-list@python.org Subject: Re: The type/object distinction and possible synthesis of OOP and imperative programming languages References: <516bd241$0$29872$c3e8da3$5496439d@news.astraweb.com> <516C3C44.6010706@rece.vub.ac.be> In-Reply-To: <516C3C44.6010706@rece.vub.ac.be> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V02:K0:NW/SPDk9Gdi1BPGpinaHmuguKTHenyLoKgSMVoo/4ts 3cXzZLC3WOHs/H/107JsZlPmbrG0AQqp1R+Or8Tcl9rJM1gAFQ VXsDj7K/EvATUp2vpUepKfaS7i+0XjuQdTSrHfZiw6BivDJYGK 0+S3gnk59CJ/T/nZXFR/62zhgJ5KM2Xna9HP1zdZG6U9a5Vmpx TZQrcsihnY5ynpf8Vlc0tXWtyTmdb34dx8cP6/zItn1JlF1q2g aGWrWk+RIQTfrdNbsrvFCt4wfMeNR11AQgGq4z9P/YBTIpRxeL TgfppWAINiS33Q+lPBl9+gtV0DZdED/Dhvn7fNQ+9+GE+ER7g= = 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: 49 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1366060446 news.xs4all.nl 2692 [2001:888:2000:d::a6]:54945 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:43643 On 04/15/2013 01:43 PM, Antoon Pardon wrote: > Op 15-04-13 12:11, Steven D'Aprano schreef: > >> >> Python's data model has always been 100% object oriented. Prior to the >> "class/type" unification, it simply had *two distinct* implementations of >> objects: types, which were written in C, and classes, which were written >> in Python. >> >> After unification, the two kinds of object were no longer entirely >> distinct -- you could then subclass types in Python code, using the same >> "class" keyword as you would use for a pure-Python class. >> >> And starting with Python 3, the last vestiges of the distinction have >> disappeared. Now, "class" and "type" are mere synonyms. Both built-in >> types and custom classes use the same mechanism. > > I had gotten my hopes up after reading this but then I tried: > > > $ python3 > Python 3.2.3 (default, Feb 20 2013, 17:02:41) > [GCC 4.7.2] on linux2 > Type "help", "copyright", "credits" or "license" for more information. > >>> class vslice (slice): > ... pass > ... > Traceback (most recent call last): > File "", line 1, in > TypeError: type 'slice' is not an acceptable base type > > > It seems types and classes are still not mere synonyms. No, it seems you're trying to use an internal detail as though it were a supported feature. From page: http://docs.python.org/3.3/reference/datamodel.html#types """Internal types A few types used internally by the interpreter are exposed to the user. Their definitions may change with future versions of the interpreter, but they are mentioned here for completeness. """ -- DaveA