如何使用pyenv在不同的python环境上安装依赖项

Question

I installed cmus in OSX and I run it with an awesome utility called cmus-osx.py which uses pyobjc and tinytag . It ran perfectly with Python 2.7.11.

But I wanted to also run mpsyt , which only works with Python 3, so I installed pyenv in order to be able to run both utilities without messing with my environment. It worked, but it caused me some problems with cmus-osx.py, so I created an issue at the GitHub repo: https://github.com/azadkuh/cmus-osx/issues/5 .

After some back and forward with the author, I realized that pyobjc became unavailable in any of the pyenv python environments after I installed pyenv . Now the notifications feature, which requires pyobjc, only works correctly when I run cmus-osx.py from system python environment. The utility's author recommended me to

reinstall (share) dependencies (pyobjc and tinytag) on every environment who launches the cmus-osx utlity

The thing is that I've no idea how to do this. I use OSX and I run cmus-osx.py from a zsh shell.

I know I should be able to figure it out by reading pyenv documentation, but I'm still learning to code and to manage a *nix based system and I want to understand what's really going on.

Answer 1

I would suggest doing some reading on the Python Virtual Environments tool, virtualenv , such as the excellent guide here .

Basically the steps are:

pip install virtualenv
virtualenv some_dir_name

You can specify which exact python to install to your virtual environment with the -p flag.

some_dir_name/bin/acivate

Windows users will need to use activate.bat

You are then in your specified python environment with no packages other than the standard library and pip installed and can install anything that you like with pip without any risk that it will impact any of your other installations.

When you are finished exit the terminal session. If you wish to go back to that environment, with all of the libraries that you installed to it , you can just activate it again.