[Numpy-discussion] Proposal of timeline for dropping Python 2.7 support

[Matthias Bussonnier]

> Just to check that I am not misunderstanding: the version of pip should
> not be more than a year old; "decades old" is just French hyperbola? Do I
> understand right?

Yes, sorry if you can't hear my french accent in writing, I can hear yours :-)

There is also a "softer" requirement on setuptools which needs to be
recent enough to 1) understand requires_python on machine that will
_create_ the sdist/wheel. or 2) accept requires_python as a kwarg
(even if does nothing), for linux system that will install from sdist.
But by end of 2018 that will be a 3 or 4 years old setuptools.

> Right, the requirement is pip 9, which is currently one year old and will be >2 years old by the time this matters for numpy.
> It does turn out that there's a bimodal distribution in the wild, where people tend to either use an up to date pip, or else use some truly ancient pip that some Linux LTS distro shipped 5 years ago. Numpy isn't the only project that > will be forcing people to upgrade, though, so I think this will work itself out. Especially since in the broken case what happens is that users end up running our setup.py on an unsupported version of python, so we'll be able to
> detect that and print some loud and informative message.

Correct, we did that for IPython, got a large spike of sdist-download
from Py2+old_pip when we released a Py3 only, the spike disappeared
after a few days.
We still had a handful of bug reports from people thinking the "You
must upgrade pip" message was not relevant, and we realised people
pinned ipython with IPython==5.0.0 instead of IPython<6.
So the "Loud informative message" should also like tell user how to
pin numpy if they can't upgrade pip.

--
Matthias

On Mon, Nov 13, 2017 at 1:33 PM, Nathaniel Smith <njs at pobox.com> wrote:
> On Nov 13, 2017 12:03, "Gael Varoquaux" <gael.varoquaux at normalesup.org>
> wrote:
>
> On Mon, Nov 13, 2017 at 10:26:31AM -0800, Matthias Bussonnier wrote:
>> This behavior is "new" (Nov/Dec 2016). [snip]
>> It _does_ require to have a version of pip which is not decades old
>
> Just to check that I am not misunderstanding: the version of pip should
> not be more than a year old; "decades old" is just French hyperbola? Do I
> understand right?
>
>
> Right, the requirement is pip 9, which is currently one year old and will be
>>2 years old by the time this matters for numpy.
>
> It does turn out that there's a bimodal distribution in the wild, where
> people tend to either use an up to date pip, or else use some truly ancient
> pip that some Linux LTS distro shipped 5 years ago. Numpy isn't the only
> project that will be forcing people to upgrade, though, so I think this will
> work itself out. Especially since in the broken case what happens is that
> users end up running our setup.py on an unsupported version of python, so
> we'll be able to detect that and print some loud and informative message.
>
> -n
>
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at python.org
> https://mail.python.org/mailman/listinfo/numpy-discussion
>