[Python-Dev] PEP 318 - posting draft

[Bob Ippolito]

On Mar 24, 2004, at 9:28 AM, Guido van Rossum wrote:

>> Actually, it should be deleted and the PEP updated.  Michael's latest 
>> patch
>> apparently supports class decorators, so it's no longer an extension.
>
> But while you're at it, please add to the PEP that I don't like the
> idea of class decorators.  I think they don't solve a real problem,
> unlike function decorators, and I think that making classes and
> functions more similar just adds confusion.

I disagree.  There's definitely a use case for something less permanent 
than a metaclass that gets a reference to a class immediately after 
creation but before it ends up in the module namespace.  For example, 
ZopeX3 interfaces and PyProtocols interfaces both use sys._getframe() 
introspection to add a temporary metaclass so that they can declare 
that a class supports (or does not support) a particular set of 
interfaces from the class body itself.  Using the [] syntax to decorate 
the class would deprecate these sorts of nasty hacks.

-bob