Hi,

Here's a patch that adds an iterator to memoryview, which makes iterating over memoryview objs considerably faster.

The following values result from a compilation with debug ON.

------------------------------------------------------------------------

Without patch:

cpython: ./python.exe -m timeit -s "a=memoryview(b'x'*1000000)" "for x in a: pass"
5 loops, best of 5: 98 msec per loop

cpython: ./python.exe -m timeit -s "a=b'x'*1000000" "for x in a: pass"
5 loops, best of 5: 68.6 msec per loop


With patch:

cpython: ./python.exe -m timeit -s "a=memoryview(b'x'*1000000)" "for x in a: pass"
5 loops, best of 5: 68.1 msec per loop

cpython: ./python.exe -m timeit -s "a=b'x'*1000000" "for x in a: pass"
5 loops, best of 5: 70 msec per loop

------------------------------------------------------------------------

Please let me know your thoughts regarding it.

Diogo

New changeset b0ac5d75a59c356c44cfc9b25077da3049dd16e9 by dxflores in branch 'master':
bpo-41732: add iterator to memoryview (GH-22119)
https://github.com/python/cpython/commit/b0ac5d75a59c356c44cfc9b25077da3049dd16e9

It would have been nice to have had a chance to look at this, but
apparently those days are over.

Thanks, Diogo for working on this issue.
And thank you for the mentoring guido!

Thanks Diogo Flores, it's a nice optimization!


Stefan Krah: "It would have been nice to have had a chance to look at this, but apparently those days are over."

The PR has been approved by two core developers. It's a nice optimization, I don't see what is the problem here.

Thank you Dong-hee Na and Victor.

@Stefan Krah: I am sorry that you didn't had the chace to try out the patch before it got merged, however iff you are curious about the any aspect of the implementation (or the motivation behind it) I am happy to discuss it in depth.