change default to Python 3

[stevengj]

The Python ecosystem finally seems to be moving decisively towards Python 3, so I think it makes sense to make Python 3 the default for new Conda.jl installations.

[stevengj]

@nalimilan, @JobJob, any thoughts on this?

[JobJob]

Good idea.

After resisting Python 3 for the better part of a decade, I switched last year. Haven't had any real issues. Seems like the vast majority of packages support Python 3 nowadays.

[stevengj]

Done.

[Balinus]

Just wondering, is there any way to tell Conda to use python2 ?

ClimateTools.jl uses Basemap as a dependency and there is a lot of problem installing Basemap on Python 3 > 3.6.

Still haven't found a TravisCI set-up that would solve Basemap problem's with Python 3.7!

Basemap works with Python 3.4 btw.

edit - Alternatively, I'm able to create a conda virtual env on my local machine and use that. Would that be possible to do on TravisCI as far as you know? I mean creating a virtual env that would specify python 3.4 etc... ?

[stevengj]

It’s explained in the Conda README.

[Balinus]

Oh!! Sorry about that. Thanks! 👍

[tkf]

Conda.add("python=3.6"); Pkg.build("PyCall") may work, too.

[oxinabox]

Conda.add("python=3.6"); Pkg.build("PyCall") may work, too.

I found that not to work great.

[tkf]

It works on all CIs #129 so it probably is specific to your setting.