New-style classes (was Re: Python 2.2 properties)

Stefan Schwarzer s.schwarzer at ndh.net
Sun Jan 20 14:49:12 CET 2002


As a related topic:

Thomas Heller wrote:
> You must derive your class from object:
> > >>> class foo(object):

I just wondered if there is something like

from __future__ import new_style_classes

to get the derivation from object by default if no base class is
specified.

>From http://python.sourceforge.net/peps/pep-0253.html it seems that this
can be accomplished by setting __metaclass__ at the module level:

Python 2.2 (#0, Dec 24 2001, 18:42:48) [EMX GCC 2.8.1] on os2emx
Type "help", "copyright", "credits" or "license" for more information.
>>> class X:
...     pass
...
>>> type(X)
<type 'class'>

vs.

Python 2.2 (#0, Dec 24 2001, 18:42:48) [EMX GCC 2.8.1] on os2emx
Type "help", "copyright", "credits" or "license" for more information.
>>> __metaclass__ = object
>>> class X:
...     pass
...
>>> type(X)
<type 'object'>

Stefan



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