[Python-Dev] PEP: Adding data-type objects to Python (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Tue Oct 31 22:12:11 CET 2006

Travis Oliphant schrieb:

I think it actually is. Perhaps I'm wrong, but a type-object is still a special kind of an instance of a meta-type. I once tried to add function pointers to a type object by inheriting from it. But, I was told that Python is not set up to handle that. Maybe I misunderstood.

I'm not quite sure what the problems are: one "obvious" problem is that the next Python version may also extend the size of type objects. But, AFAICT, even that should "work", in the sense that this new version should check for the presence of a flag to determine whether the additional fields are there. The only tricky question is how you can find out whether your own extension is there.

If that is a common problem, I think a framework could be added to support extensible type objects (with some kind of registry for additional fields, and a per-type-object indicator whether a certain extension field is present).

Let me be very clear. The whole reason I make any statements about ctypes is because somebody else brought it up. I'm not trying to replace ctypes and the way it uses type objects to represent data internally.

Ok. I understood you differently earlier.

Regards, Martin

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