[Python-Dev] User's complaints

Armin Rigo arigo at tunes.org
Mon Jul 17 20:22:35 CEST 2006


Hi Jeroen,

On Thu, Jul 13, 2006 at 02:02:22PM +0200, Jeroen Ruigrok van der Werven wrote:
> He doesn't specifically need the builtin types to be extendable. It's
> just nice to be able to define a single class in multiple modules.

There are various simple ways to do this; the one I'm using from time to
time is the "extendabletype" metaclass from:

   http://codespeak.net/svn/pypy/dist/pypy/annotation/pairtype.py

Example:

   class A:
       __metaclass__ = extendabletype
       def f(...): ...

Somewhere else:

   class __extend__(A):
       def g(...): ...

FWIW the above 30-lines file also contains a fast double-dispatch
multimethod implementation :-)


A bientot,

Armin


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