[Numpy-discussion] Please keep Numpy master working on Py3
pav at iki.fi
Tue Feb 1 20:11:19 EST 2011
On Tue, 01 Feb 2011 16:42:04 -0800, Mark Wiebe wrote:
[clip: problem 1]
> This looks like it's a problem in new_iterator_pywrap.c, in
> PySequenceMethods npyiter_as_sequence. I got this error when trying to
> slice before implementing the slot sq_slice. I copied the definition
> from array_as_sequence, which I thought would already have any
> adjustments for Py3. The value in that slot shouldn't be NULL, though,
> so I don't know why it's giving the error, maybe the struct definition
> changed, and somehow in the array sequence methods that gets masked? Or
> maybe the assignment slice slot needs to be filled as well, but that
> doesn't seem right to me.
The slot sq_slice is in the struct on Python 3, but the entry is a dummy
It appears slices are supposed to be handled in PyMappingMethod. (If you
walk through the __getitem__ code for ndarray, you'll note that if it
encounters a single slice, it falls back to calling the PySequence
The Python C-API docs don't seem to say much on the status of sq_slice on
Python 2, but at least on the Python side I know that the corresponding
__*slice__ hooks are deprecated in favor of the __*item__ routines since
[clip: problem 2]
> I see, in Py3 oct and hex call array_index instead of array_oct and
This is because the __oct__ and __hex__ C-slots were removed from
PyNumberMethods on Py3.
> I think changing the self-reference exceptions in
> int/long/float/oct/hex to TypeError instead of ValueError is probably
> a good way to make this consistent.
Probably a good idea, since the other errors there are also TypeErrors.
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