Hi all, Apologies if this mail appear out of thread I just subscribed to respond.
Yeah, agreed. I don't feel like this is incompatible with the spirit of python3statement.org, though looking at the text I can see how it's not clear. My guess is they'd be happy to adjust the text, especially if it lets them add numpy :-). CC'ing Thomas and Matthias.
Happy to see NumPy at least having this conversation ! I agree with Thomas, we're pretty loose on what dropping support means; one of the main reason for the Python-3-Statement is communication to users and other project; and covey that there is a strong intent that you have until 2020 to get ready (if not before). The voice of NumPy have a huge weight in the balance. I quickly went through the thread and have a few responses:
NumPy (and to a lesser extent SciPy) is in a tough position being at the bottom of many scientific Python programming stacks. Whenever you drop Python 2 support is going to upset someone.
And that is why you should decide of doing it at some point, and telling it to the world and the sooner you decide and advertise it (regardless of effective "deadline" the better. The Scientific Python is in a catch 22 position; Most of the ecosystem will not drop 2.7 because "numpy is still compatible python 2.7", and numpy does not drop it because "many packages rely on numpy support for 2.7".
We'd have to make sure we could persuade pypi to give the older version for Windows, by default - I don't know if that is possible.
I don't think there is, though if you tag a release with `requires_python>3.3`, then pip 9+ users on python 2.7 will not even realise there are new release compatible only with 3.3+. Technically you can make numpy a meta-package that requires numpy-27 on windows only... but it has its own drawbacks.
And yet another is that when we do finally drop 2.7, I think we'd want to get the full benefits of doing so. That's new 3.x features (@ in particular), cleaning up lots of support code, etc.
Regarding http://www.python3statement.org/: I'd say that as long as there are people who want to spend their energy on the LTS release (contributors *and* enough maintainer power to review/merge/release), we should not actively prevent them from doing that.
These two are _in practice_ against each other; if you do major cleaning then most backports will have a hard time being auto applied (just a warning). If you have a team that want to do a LTS I would suggest "cleaning" only when you are actually touching some code and the python-2 support code is in the way. not cleaning "for the sake of cleaning" at least until the 2 code base are far enough. We have a bot on Jupyter/Matplotlib that help to backport PRs to older branches. I'm happy to open it to the numpy org if it helps.
It is too ambitious to pledge to drop support for Python 2.7 no later than 2020, coinciding with the Python development team’s timeline for dropping support for Python 2.7?
The hardest part is communication. And not just "We're dropping in 2020" but also "We still care about you, 2.7 users", ans especially tell 2.7 users and old pip users how to correctly pip their dependency on numpy (to still get LTS if LTS there is) One more thing, there is a lot of of discussion about a "Volonteer LTS", you may also want to consider a partnership with a company for an officially recommended commercial offer. Thanks, -- Matthias On Thu, Nov 9, 2017 at 10:21 AM, Nathaniel Smith <njs@pobox.com> wrote:
See Thomas's reply quoted below (it was rejected by the mailing list since he's not subscribed):
On Nov 9, 2017 01:24, "Thomas Kluyver" <thomas@kluyver.me.uk> wrote:
On Thu, Nov 9, 2017, at 08:52 AM, Nathaniel Smith wrote:
On Nov 8, 2017 23:59, "Ralf Gommers" <ralf.gommers@gmail.com> wrote:
Regarding http://www.python3statement.org/: I'd say that as long as there are people who want to spend their energy on the LTS release (contributors *and* enough maintainer power to review/merge/release), we should not actively prevent them from doing that.
Yeah, agreed. I don't feel like this is incompatible with the spirit of python3statement.org, though looking at the text I can see how it's not clear. My guess is they'd be happy to adjust the text, especially if it lets them add numpy :-). CC'ing Thomas and Matthias.
Thanks Nathaniel. We have (IMO) left a degree of deliberate ambiguity around precisely what 'drop support' means, because it's not going to be the same for all projects. The nature of open source also means that there can be ambiguity over what 'support' entails and who is considered part of the project.
I would say that the idea of the statement is compatible with an LTS release series receiving critical bugfixes beyond 2020, while the main energy of the project is focused on Py3-only feature releases.
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Thomas