[Python-3000] Using memoryviews

[Antoine Pitrou]

Josiah Carlson <josiah.carlson <at> gmail.com> writes:
> 
> From what I understand of the memoryview when I tried to do the same
> thing a few months ago (use memoryview to replace buffer in
> asyncore/asynchat), memoryview is incomplete.  It didn't support
> character buffer slicing (you know, the 'offset' and 'size' arguments
> that were in buffer), and at least a handful of other things (that I
> can't remember at the moment).

You should try again, memoryview now supports slicing (with the usual Python
syntax, e.g. m[2:5]) as well as slice assignment (with the fairly sensible
limitation that you can't resize the underlying buffer). There's no real doc for
it, but you can look at test_memoryview.py in the Lib/test directory to have a
fairly comprehensive list of the things currently supported.

I also support the addition of official functions or macros to access the
underlying fields of the Py_buffer struct, rather than access them directly from
3rd party code. Someone please open an issue for that in the tracker.

The big, big limitation of memoryviews right now is that they only support
one-dimensional byte buffers. The people interested in more complex arrangements
(that is, Scipy/Numpy people) have been completely absent from the python-dev
community for many months now, and I don't think anyone else cares enough to do
the job instead of them.

Regards

Antoine.