Linking Julia to different Anaconda virtual environments

[John Hammonds]

I have been using Anaconda Python with their virtual environments.  I am starting to look into Julia and would like to be able to use PyCall to call in python code.  I am using the virtual environments to manage different projects/versions.  My Base Python is fairly minimal, I install most packages in the virtenvs,  When I use PyCall and @pyimport, I seem to only find packages in my base anaconda installation.  Is there a clean way to switch between different virtual environments when I am using Julia?

[Scott T]

Hi John,

Because PyCall links directly to the Python libraries, you have to rebuild it every time you want to use a different version of Python. That includes switching virtual environments. You do this by setting the environment variable PYTHON (ENV["PYTHON"] from within Julia) to the location of the python executable and then running Pkg.build("PyCall"). The process is pretty quick so you could probably write a function in your .juliarc.jl file to let you switch between environments. I haven't done this yet because I just use the root conda environment, but it's what I would do if I needed to switch between several.

Cheers,

Scott