[Q] Default Python interpreter

[jaklan]

Hi, I can't find it in docs - in what way the default Python interpreter path is resolved? I'm using Python 3.7 with Homebrew, but I also have Python@3.8 which was installed as a dependency by some library. It's Keg-only, so it's not visible in /usr/local/bin. But since then, the packages were installed with Python 3.8 by default and I had to manually use --python flag to switch it back to 3.7 each time. I even deleted .local/pipx/shared folder and tried to recreate with reinstall-all, but 3.8 was used anyway as long as I didn't use --python flag.

[uranusjr]

The default Python interpreter is whatever sys.executable reports (i.e. what pipx was initially installed against), and PATH has no effect on it. This can cause problems with a few environments, and there are workarounds available. My pipx-standalone for example carries a patch to use perform custom Python version detection. Also see #146, #294. I think this is an issue the Homebrew formula maintainers need to address, but maybe pipx can organise the code to make it easier for downstream packagers to patch the default Python inrepreter logic.

[jaklan]

@uranusjr thanks for the answer. As I cen see, pipx formula in Homebrew depends on Keg-only python@3.8 (for whatever reason), so as I understand that would be the default interpreter. Is there any way to install pipx via brew with another Python version, e.g. 3.7?

[AlJohri]

@jaklan No, brew installed pipx always uses the latest python. Homebrew is slowly porting all formula to manually depend on python 3.8. When this is complete, the global brew python will also change from 3.7 to 3.8.

[itsayellow]

Closing because #448 clears up documenting this (use pipx install --help to see what pipx thinks is the default python executable) and also allows setting the default python (use PIPX_DEFAULT_PYTHON env variable.)