On Aug 22, 2013, at 11:57 PM, David Cournapeau <cournape@gmail.com> wrote:

npy_long is indeed just an alias to C long,

Which means it's likely broken on 32 bit platforms and 64 bit MSVC.

np.long is an alias to python's long:

But python's long is an unlimited type--it can't be mapped to a c type at all.

arch -32 python -c "import numpy as np; print np.dtype(np.int); print np.dtype(np.long)"

int32

int64

So this is giving us a 64 bit int--not a bad compromise, but not a python long--I've got to wonder why the alias is there at all.

arch -64 python -c "import numpy as np; print np.dtype(np.int); print np.dtype(np.long)"

int64

int64

Same thing on 64 bit.

So while np.long is an alias to python long--it apparently is translated internally as 64 bit -- everywhere?

So apparently there is no way to get a "platform long". ( or, for that matter, a platform anything else, it's just that there is more consistancy among common platforms for the others)