Add pyenv compatibility

I’ve got a CLI-tool (tmux-res) I built for handling some common tasks in my TMUX-environment which I built a while back. For fun I wanted to try installing it via pipx but it doesn’t work.

This is the package: https://pypi.org/project/tmux-res/

 $ pyenv global 3.7.2
 $ python --version
Python 3.7.2

 $ pipx install tmux-res
  Could not find a version that satisfies the requirement tmux-res (from versions: )
No matching distribution found for tmux-res
'/Users/hultner/.local/pipx/venvs/tmux-res/bin/python -m pip install tmux-res -q' failed

 $ pip install tmux-res
Collecting tmux-res
  Downloading https://files.pythonhosted.org/packages/09/80/a0294c244aebbdc9f13c06b182a7c1857618da20eabd1c88c4f449dbdf09/tmux_res-0.4.8-py3-none-any.whl
Collecting python-dotenv (from tmux-res)
  Downloading https://files.pythonhosted.org/packages/8c/14/501508b016e7b1ad0eb91bba581e66ad9bfc7c66fcacbb580eaf9bc38458/python_dotenv-0.10.1-py2.py3-none-any.whl
Collecting Click (from tmux-res)
  Using cached https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl
Installing collected packages: python-dotenv, Click, tmux-res
Successfully installed Click-7.0 python-dotenv-0.10.1 tmux-res-0.4.8
You are using pip version 18.1, however version 19.0.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

[cs01]

pipx is like any other python package with an entry point. If you run which pipx you’ll get a path that gets executed. I get

>> which pipx
/home/csmith/.local/bin/pipx

At the top of /home/csmith/.local/bin/pipx is #!/usr/bin/python3.6 since I installed with python3.6 -m pip install --user pipx.

If I change it to #!/usr/bin/python3.7 it will try to use 3.7 and will search the site-packages directory for python3.7, and will fail since it was installed for python3.6.

Installing it with 3.7 and then trying again works fine. And subsequent packages are installed with the newer version since that’s what the pipx executable file runs at startup: /usr/bin/python3.7.

> python3.6 -m pip install pipx --user
> pipx install black
> python3.6 -m pip uninstall pipx
> python3.7 -m pip install pipx --user
> pipx install pycowsay
> pipx list
venvs are in /home/csmith/.local/pipx/venvs
apps are exposed on your $PATH at /home/csmith/.local/bin
   package black 19.3b0, Python 3.6.8
    - black
    - blackd
   package pycowsay 0.0.0.1, Python 3.7.3
    - pycowsay

[cs01]

Having the default behaviour configurable via a environment variable coupled with appropriate documentation sounds like the best solution then from my point of view then.I could give it a shot if it’s okay.

Sounds good! Thank you.