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

[Bryan Van de ven]

> On Nov 8, 2017, at 10:50, Peter Cock <p.j.a.cock at googlemail.com> wrote:
> 
> 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.

Existing versions of NumPy will still exist and continue to work with Python 2.7. If users want to say with Python 2.7, that's fine, they will just have to rely on those older/LTS versions. I personally would be happy for projects at the bottom of stacks to take an activist stance and make decisions to actively encourage movement to Python 3. 

> 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?

Developing NumPy is hard, as it is. Everything that can be done to simplify things for the current maintainers and help attract new contributors should be done. It is not reasonable to ask a few (largely volunteer) people to shoulder the burden and difficulties of supporting Python 2.7 for several additional *years* of their life. 

I agree entirely with Nick Coghlan's comments from another discussion, and think they apply equally well in this instance:

"""
While it's entirely admirable that many upstream developers are generous enough to help their end users work around this inertia, in the long run doing so is detrimental for everyone concerned, as long term sustaining engineering for old releases is genuinely demotivating for upstream developers (it's a good job, but a lousy way to spend your free time) and for end users, working around institutional inertia this way reduces the pressure to actually get the situation addressed properly.
"""

Thanks,

Bryan