[Python-3000] Metaclasses in Py3K

Ronald Oussoren ronaldoussoren at mac.com
Mon Dec 18 08:17:51 CET 2006


On 16 Dec, 2006, at 22:39, Steven Bethard wrote:

>
>> The main issue for me is that I think that its important to  
>> distinguish
>> between get/set operations that are done at class definition time,  
>> and
>> get/set operations that are done later, after the class is created.
>
> Why?  Can you explain your use case?  Everything I'd care to do would
> treat later get/set operations on the class in the same way.

I don't know about Phillip, but my usecase for this would be setting  
up C datastructures that cannot be updated later on.  That is, at the  
end of the class definition a metaclass (possibly written in C) sets  
up a datastructure in C from information found in the class dict with  
a library that doesn't allow updates of said datastructure afterwards.

My main usage for that is PyObjC: we have objc.ivar() properties that  
create an instance variable in the corresponding Objective-C class.  
Those can be added during class construction but not afterwards  
(because that would break existing instances).

Ronald

>
> STeVe
> -- 
> I'm not *in*-sane. Indeed, I am so far *out* of sane that you appear a
> tiny blip on the distant coast of sanity.
>         --- Bucky Katt, Get Fuzzy
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