Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!rt.uk.eu.org!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <python-python-list@m.gmane.org>
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; 'example:': 0.03; 'anyway.': 0.04; 'missed': 0.09; 'python': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'def': 0.10; '(line': 0.16; 'fancy': 0.16; 'new-style': 0.16; 'old-style': 0.16; 'received:80.91.229.3': 0.16; 'received:dip.t-dialin.net': 0.16; 'received:plane.gmane.org': 0.16; 'received:t-dialin.net': 0.16; 'thanks!!!': 0.16; 'wrote:': 0.17; '>>>': 0.18; 'all,': 0.21; 'import': 0.21; "i've": 0.23; 'seems': 0.23; 'pass': 0.25; 'header :User-Agent:1': 0.26; 'wonder': 0.27; 'header:X-Complaints-To:1': 0.28; 'yes.': 0.29; 'skip:_ 10': 0.29; 'source': 0.29; 'class': 0.29; 'maybe': 0.29; 'expect': 0.31; 'code': 0.31; 'to:addr :python-list': 0.33; 'thanks': 0.34; 'something': 0.35; 'received:org': 0.36; 'created': 0.36; 'subject:: ': 0.38; 'object': 0.38; 'to:addr:python.org': 0.39; 'header:Received:5': 0.40; 'think': 0.40; 'dear': 0.66; 'pytypeobject': 0.84; 'abc': 0.91
X-Injected-Via-Gmane: http://gmane.org/
To: python-list@python.org
From: Peter Otten <__peter__@web.de>
Subject: RE: metatype
Date: Tue, 12 Mar 2013 07:50:21 +0100
Organization: None
References: <BAY404-EAS28100DF680E616854A6CE44A3E10@phx.gbl> <BAY176-W39386733D837D0A95A985FA3E20@phx.gbl>
Mime-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7Bit
X-Gmane-NNTP-Posting-Host: p508493c1.dip.t-dialin.net
User-Agent: KNode/4.7.3
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.3219.1363070989.2939.python-list@python.org>
Lines: 33
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1363070989 news.xs4all.nl 6936 [2001:888:2000:d::a6]:54010
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:41111

shangyu wrote:

> Hi dear all,
> I have following Python code
> class mydict(dict):
>     def __init__(self):
>         pass
> I wonder how this new type get created . What is the type of metatype in
> the following line ? type = (PyTypeObject *)metatype->tp_alloc(metatype,
> nslots); (line 2296 of typeobject.c Python2.7.3 source code)
> It seems PyDict_Type . If so , how do I expect the tp_alloc will return a
> PyTypeObject object ? Maybe I've missed something ? Many thanks!!!

> I think I've found it out . For new-style class it's PyType_Type and for
> old-style class it's PyClass_Type . Thanks anyway.

Yes. You can find that out without resorting to the C API:

>>> class A(dict): pass
... 
>>> type(A)
<type 'type'>

A fancy example:

>>> import abc
>>> class B:
...     __metaclass__ = abc.ABCMeta
... 
>>> type(B)
<class 'abc.ABCMeta'>