[Numpy-discussion] Array Protocol change for Python 2.6 (original) (raw)

Thomas Heller theller at python.net
Fri Jun 16 15:25:52 EDT 2006


Robert Kern wrote:

Francesc Altet wrote:

A Divendres 09 Juny 2006 11:54, Albert Strasheim va escriure:

Just out of curiosity:

In [1]: x = N.array([]) In [2]: x.arraydata Out[2]: ('0x01C23EE0', False) Is there a reason why the arraydata tuple stores the address as a hex string? I would guess that this representation of the address isn't the most useful one for most applications. Good point. I hit this before and forgot to send a message about this. I agree that a integer would be better. Although, now that I think about this, I suppose that the issue should be the difference of representation of longs in 32-bit and 64-bit platforms, isn't it? Like how Win64 uses 32-bit longs and 64-bit pointers. And then there's signedness. Please don't use Python ints to encode pointers. Holding arbitrary pointers is the job of CObjects.

(Sorry, I'm late in reading this thread. I didn't know there were so many numeric groups)

Python has functions to convert pointers to int/long and vice versa: PyInt_FromVoidPtr() and PyInt_AsVoidPtr(). ctypes uses them, ctypes also represents addresses as ints/longs.

Thomas



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