Message 276411 - Python tracker

Message276411

Author	skrah
Recipients	benjamin.peterson, christian.heimes, doko, ned.deily, serhiy.storchaka, skrah, vstinner, ztane
Date	2016-09-14.10:01:53
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1473847313.49.0.394099287528.issue28055@psf.upfronthosting.co.za>
In-reply-to

Content
I see. No, most NumPy arrays are C-contiguous. Multi-dimmensional arrays are contiguous, too. Non C-contiguous arrays arise mostly during slicing or if they're Fortran-order to begin with. But NumPy aside, it's weird to have slice of a huge regular bytes view (this particular slice is still C-contiguous) that is suddenly copied because the alignment requirements changed. I really prefer a simple rule for memoryview: If the data is C-contiguous, you get the fast path.

Content

I see. No, most NumPy arrays are C-contiguous. Multi-dimmensional arrays
are contiguous, too.

Non C-contiguous arrays arise mostly during slicing or if they're
Fortran-order to begin with.


But NumPy aside, it's weird to have slice of a huge regular bytes view
(this particular slice is still C-contiguous) that is suddenly copied
because the alignment requirements changed.

I really prefer a simple rule for memoryview: If the data is C-contiguous,
you get the fast path.

History
Date	User	Action	Args
2016-09-14 10:01:53	skrah	set	recipients: + skrah, doko, vstinner, christian.heimes, benjamin.peterson, ned.deily, serhiy.storchaka, ztane
2016-09-14 10:01:53	skrah	set	messageid: <1473847313.49.0.394099287528.issue28055@psf.upfronthosting.co.za>
2016-09-14 10:01:53	skrah	link	issue28055 messages
2016-09-14 10:01:53	skrah	create