Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path: <ethan@stoneleaf.us>
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; 'attribute': 0.05; 'case.': 0.05; 'class,': 0.07; 'python': 0.09; 'descriptor': 0.09; 'exist.': 0.09; 'exists,': 0.09; 'from:addr:ethan': 0.09; 'from:addr:stoneleaf.us': 0.09; 'from:name:ethan furman': 0.09; 'message-id:@stoneleaf.us': 0.09; 'received:184.172': 0.09; 'received:gator410.hostgator.com': 0.09; '~ethan~': 0.09; 'result.': 0.15; 'attributes:': 0.16; 'attrname': 0.16; 'bases,': 0.16; 'descriptor,': 0.16; 'non-data': 0.16; 'received:72.11': 0.16; 'received:72.11.125': 0.16; 'received:72.11.125.166': 0.16; 'received:gateway13.websitewelcome.com': 0.16; 'retrieving': 0.16; 'exists': 0.17; "shouldn't": 0.17; 'url:article': 0.17; 'subject:skip:i 10': 0.22; 'raise': 0.24; 'header:User-Agent:1': 0.26; '[1]': 0.27; 'question': 0.27; '[2]': 0.27; 'found.': 0.27; "doesn't": 0.28; 'steps:': 0.29; 'points': 0.29; 'class': 0.29; "i'm": 0.29; 'returned': 0.30; 'point': 0.31; 'anybody': 0.32; 'to:addr:python-list': 0.33; 'wrong': 0.34; 'sequence': 0.35; 'too.': 0.35; 'there': 0.35; '(i.e.': 0.36; 'does': 0.37; 'data': 0.37; 'object': 0.38; 'skip:o 20': 0.38; 'to:addr:python.org': 0.39; 'step': 0.39; 'header:Received:5': 0.40; 'here': 0.65; 'received:69.56': 0.65; 'special': 0.73; '(print': 0.84; 'to:name:python': 0.84
Date: Fri, 05 Oct 2012 10:39:53 -0700
From: Ethan Furman <ethan@stoneleaf.us>
User-Agent: Thunderbird 1.5.0.10 (Windows/20070221)
MIME-Version: 1.0
To: Python <python-list@python.org>
Subject: instance.attribute lookup
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-AntiAbuse: This header was added to track abuse, please include it with any abuse report
X-AntiAbuse: Primary Hostname - gator410.hostgator.com
X-AntiAbuse: Original Domain - python.org
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - stoneleaf.us
X-BWhitelist: no
X-Source: 
X-Source-Args: 
X-Source-Dir: 
X-Source-Sender: ([192.168.10.136]) [72.11.125.166]:3014
X-Source-Auth: ethan+stoneleaf.us
X-Email-Count: 1
X-Source-Cap: dG9idWs7dG9idWs7Z2F0b3I0MTAuaG9zdGdhdG9yLmNvbQ==
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.1861.1349459170.27098.python-list@python.org>
Lines: 35
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1349459170 news.xs4all.nl 6955 [2001:888:2000:d::a6]:59720
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:30827

There is a StackOverflow question [1] that points to this on-line book 
[2] which has a five-step sequence for looking up attributes:

 > When retrieving an attribute from an object (print
 > objectname.attrname) Python follows these steps:
 >
 > 1. If attrname is a special (i.e. Python-provided) attribute for
 > objectname, return it.
 >
 > 2. Check objectname.__class__.__dict__ for attrname. If it exists and
 > is a data-descriptor, return the descriptor result. Search all bases
 > of objectname.__class__ for the same case.
 >
 > 3. Check objectname.__dict__ for attrname, and return if found. If
 > objectname is a class, search its bases too. If it is a class and a
 > descriptor exists in it or its bases, return the descriptor result.
 >
 > 4. Check objectname.__class__.__dict__ for attrname. If it exists and
 > is a non-data descriptor, return the descriptor result. If it exists,
 > and is not a descriptor, just return it. If it exists and is a data
 > descriptor, we shouldn't be here because we would have returned at
 > point 2. Search all bases of objectname.__class__ for same case.
 >
 > 5. Raise AttributeError

I'm thinking step 1 is flat-out wrong and doesn't exist.  Does anybody 
know otherwise?

~Ethan~

[1]
http://stackoverflow.com/q/10536539/208880

[2]
http://www.cafepy.com/article/python_attributes_and_methods/ch01s05.html