[Numpy-discussion] Array Protocol change for Python 2.6

Thomas Heller theller at python.net
Fri Jun 16 14:25:52 CDT 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.__array_data__
>>>Out[2]: ('0x01C23EE0', False)
>>>
>>>Is there a reason why the __array_data__ 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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