Mailman 3 December 2020 - NumPy-Discussion

NumPy Community Meeting Wednesday
by Sebastian Berg Dec. 8, 2020

Dec. 8, 2020

Hi all, There will be a NumPy Community meeting Wednesday December 9th at 12pm Pacific Time (20:00 UTC). Everyone is invited and encouraged to join in and edit the work-in-progress meeting topics and notes at: https://hackmd.io/76o-IxCjQX2mOXO_wwkcpg?both Best wishes Sebastian

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NEP 42 being accepted (New and extensible DTypes)
by Sebastian Berg Dec. 7, 2020

Dec. 7, 2020

Hi all, It has been a very long time since my emails asking to accept the NEP: https://mail.python.org/pipermail/numpy-discussion/2020-October/081038.html Happy to wait for a bit longer, but without any hesitation/points raised, I consider the NEP as accepted. At this time most of the important points have even been included in NumPy itself. That leaves still a lot of freedom to modify the final public API, but that is not the most important part with respect to moving forward. I have opened a PR to that affect: https://github.com/numpy/numpy/pull/17953 Cheers, Sebastian

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Rules for argument parsing/forwarding in __array_function__ and __array_ufunc__
by Sebastian Berg Dec. 6, 2020

Dec. 6, 2020

Hi all, I am curious about the correct argument for "normalizing" and forwarding arguments in `__array_function__` and `__array_ufunc__`. I have listed the three rules as I understand how the "right" way is below. Mainly this is just to write down the rules that I think we should aim for in case it comes up. I admit, I do have "hidden agendas" where it may come up: * pytorch breaks rule 2 in their copy of `__array_function__`, because it allows to easily optimize away some overheads. * `__array_ufunc__` breaks rule 1 (it allows too much) and I think we should be OK to change that [1]. * A few `__array_function__`s break rule 3. That is completely harmless, but it might be nice to just be clear whether we consider it technically wrong. [2] Rules ----- 1. If an argument is invalid in NumPy it is considered and error. For example: np.log(arr, my_weird_argument=True) is always an error even if the `__array_function__` implementation of `arr` would support it. NEP 18 explicitly says that allowing forwarding could be done, but will not be done at this time. 2. Arguments must only be forwarded if they are passed in: np.mean(cupy_array) ends up as `cupy.mean(cupy_array)` and not: cupy.mean(cupy_array, axis=None, dtype=None, out=None, keepdims=False, where=True) meaning that CuPy does not need to implement all of those kwargs and NumPy can add new ones without breaking anyones code. 3. NumPy should not check the *validity* of the arguments. For example: `np.add.reduce(xarray, axis="long")` should probably work in xarray. (`xarray.DataArray` does not actually implement the above.) But a string cannot be used as an axis in NumPy. Cheers, Sebastian [1] I think `dask` breaks this rule by using an `output_dtypes` keyword. I would just consider this a valid exception and keep allowing it. In fact, `output_dtypes` may very well be a useful argument for NumPy itself. `dtype` looks like it serves that purpose, but it does not have quite the same meaning. This has been discussed also here: https://github.com/numpy/numpy/issues/8892 [2] This is done for performance reasons, although it is entirely avoidable. However, avoiding it might just add a bunch of annoying code unless part of a larger maintenance effort.

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NumPy 1.20.0rc1 released
by Charles R Harris Dec. 3, 2020

Dec. 3, 2020

Hi All, On behalf of the NumPy team I am pleased to announce the release of NumPy 1.20.0rc1. This NumPy release is the largest to date, containing some 654 merged pull requests contributed by 182 people. See the list of highlights below. The Python versions supported for this release are 3.7-3.9, support for Python 3.6 has been dropped. Wheels can be downloaded from PyPI <https://pypi.org/project/numpy/1.20.0rc1/>; source archives, release notes, and wheel hashes are available on Github <https://github.com/numpy/numpy/releases/tag/v1.20.0rc1>. Linux users will need pip >= 0.19.3 in order to install manylinux2010 and manylinux2014 wheels. *Highlights* - Annotations for NumPy functions. This work is ongoing and improvements can be expected pending feedback from users. - Wider use of SIMD to increase execution speed of ufuncs. Much work has been done in introducing universal functions that will ease use of modern features across different hardware platforms. This work is ongoing. - Preliminary work in changing the dtype and casting implementations in order to provide an easier path to extending dtypes. This work is ongoing but enough has been done to allow experimentation and feedback. - Extensive documentation improvements comprising some 185 PR merges. This work is ongoing and part of the larger project to improve NumPy's online presence and usefulness to new users. - Further cleanups related to removing Python 2.7. This improves code readability and removes technical debt. - Preliminary support for the upcoming Cython 3.0. *Contributors* A total of 182 people contributed to this release. People with a "+" by their names contributed a patch for the first time. - Aaron Meurer + - Abhilash Barigidad + - Abhinav Reddy + - Abhishek Singh + - Al-Baraa El-Hag + - Albert Villanova del Moral + - Alex Leontiev + - Alex Rockhill + - Alex Rogozhnikov - Alexander Belopolsky - Alexander Kuhn-Regnier + - Allen Downey + - Andras Deak - Andrea Olivo andryandrew(a)gmail.com andryandrew + - Andrew Eckart + - Anirudh Subramanian - Anthony Byuraev + - Antonio Larrosa + - Ashutosh Singh + - Bangcheng Yang + - Bas van Beek + - Ben Derrett + - Ben Elliston + - Ben Nathanson + - Bharat Medasani + - Bharat Raghunathan - Bijesh Mohan + - Bradley Dice + - Brandon David + - Brandt Bucher - Brian Soto + - Brigitta Sipocz - Cameron Blocker + - Carl Leake + - Charles Harris - Chris Brown + - Chris Vavaliaris + - Chunlin Fang - CloseChoice + - Daniel G. A. Smith + - Daniel Hrisca - Daniel Vanzo + - David Pitchford + - Davide Dal Bosco + - Dima Kogan + - Dmitry Kutlenkov + - Douglas Fenstermacher + - Dustin Spicuzza + - E. Madison Bray + - Elia Franzella + - Enrique Matías Sánchez (Quique) + - Erfan Nariman | Veneficus + - Eric Larson - Eric Moore - Eric Wieser - Erik M. Bray - EthanCJ-git + - Etienne Guesnet + - Felix Divo - Frankie Robertson + - Ganesh Kathiresan - Gengxin Xie - Gerry Manoim + - Guilherme Leobas - Hassan Kibirige - Hugo Mendes + - Hugo van Kemenade - Ian Thomas + - InessaPawson + - Isabela Presedo-Floyd + - Isuru Fernando - Jakob Jacobson + - Jakob Jakobson + - Jakub Wilk - James Myatt + - Jesse Li + - John Hagen + - John Zwinck - Joseph Fox-Rabinovitz - Josh Wilson - Jovial Joe Jayarson + - Julia Signell + - Jun Kudo + - Karan Dhir + - Kaspar Thommen + - Kerem Hallaç - Kevin Moore + - Kevin Sheppard - Klaus Zimmermann + - LSchroefl + - Laurie + - Laurie Stephey + - Levi Stovall + - Lisa Schwetlick + - Lukas Geiger + - Madhulika Jain Chambers + - Matthias Bussonnier - Matti Picus - Melissa Weber Mendonça - Michael Hirsch - Nick R. Papior - Nikola Forró - Noman Arshad + - Paul YS Lee + - Pauli Virtanen - Paweł Redzyński + - Peter Andreas Entschev - Peter Bell - Philippe Ombredanne + - Phoenix Meadowlark + - Piotr Gaiński - Raghav Khanna + - Raghuveer Devulapalli - Rajas Rade + - Rakesh Vasudevan - Ralf Gommers - Raphael Kruse + - Rashmi K A + - Robert Kern - Rohit Sanjay + - Roman Yurchak - Ross Barnowski - Royston E Tauro + - Ryan C Cooper + - Ryan Soklaski - Safouane Chergui + - Sahil Siddiq + - Sarthak Vineet Kumar + - Sayed Adel - Sebastian Berg - Sergei Vorfolomeev + - Seth Troisi - Sidhant Bansal + - Simon Gasse - Simon Graham + - Stefan Appelhoff + - Stefan Behnel + - Stefan van der Walt - Steve Dower - Steve Joachim + - Steven Pitman + - Stuart Archibald - Sturla Molden - Susan Chang + - Takanori H + - Tapajyoti Bose + - Thomas A Caswell - Tina Oberoi - Tirth Patel - Tobias Pitters + - Tyler Reddy - Veniamin Petrenko + - Wansoo Kim + - Warren Weckesser - Wei Yang + - Wojciech Rzadkowski - Yang Hau + - Yogesh Raisinghani + - Yu Feng - Yuya Unno + - Zac Hatfield-Dodds - Zuhair Ali-Khan + - @abhilash42 + - @bernie gray + - @danbeibei + - @dojafrat - @dpitch40 + - @forfun + - @iamsoto + - @jbrockmendel + - @leeyspaul + - @mitch + - @prateek arora + - @qiyu8 + - @serge-sans-paille + - @skywalker + - @stphnlyd + - @xoviat - @谭九鼎 + - @JMFT + - @Jack + - @Neal C + Cheers, Charles Harris

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Precompute shape of ufunc output.
by drtodd13 Dec. 2, 2020

Dec. 2, 2020

If I want to provide the "out" kwarg to, for example, a reduce ufunc then I need to know the shape of the output given the other set of inputs. Is there a utility function to take these arguments and just compute what the shape of the output is going to be without actually computing the result? Would be nice if there were a standard kwarg for many functions that just tells you the shape of the output without actually computing it but I don't think that exists. Any ideas appreciated. Thanks. -- Sent from: http://numpy-discussion.10968.n7.nabble.com/

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NumPy Development Meeting Wednesday - Triage Focus
by Sebastian Berg Dec. 1, 2020

Dec. 1, 2020

Hi all, Our bi-weekly triage-focused NumPy development meeting is today (Wednesday, November 18th) at 11 am Pacific Time (19:00 UTC). Everyone is invited to join in and edit the work-in-progress meeting topics and notes: https://hackmd.io/68i_JvOYQfy9ERiHgXMPvg I encourage everyone to notify us of issues or PRs that you feel should be prioritized, discussed, or reviewed. Best regards Sebastian

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NumPy 1.20.x branch in two weeks
by Charles R Harris Dec. 1, 2020

Dec. 1, 2020

Hi All, Time to start planning for the 1.20.x branch. These are my thoughts at the moment: - Keep support for Python 3.6. Python 3.7 came out in June 2018, which seems too recent to be our oldest supported version. - Drop Python 3.6 for 1.21.x, that will make the oldest supported version about three years old. - Drop manylinux1 for 1.21.x. It would be nice to drop earlier, but manylinux2010 is pretty recent. There were 33 wheels in the 1.19.3 release, I think we can live with that for 1.20.x. I'm more worried about our tools aging out. After Python has settled into its yearly release cycle, I think we will end up supporting the latest 4 versions. Thoughts? Chuck

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