psa — Python Standalone Manager

Pure-Python CLI to list, download, and extract astral-sh/python-build-standalone prebuilt Python distributions.

psa's job is to bootstrap Python on a system. Projects then create their venvs with the interpreter they need (--python=python3.13); psa deliberately has no project-management features.

Supported platforms:

• macOS Apple Silicon (aarch64-apple-darwin)
• Linux x86_64 glibc (x86_64-unknown-linux-gnu)

It focuses on the install_only / install_only_stripped archives, and has no mandatory dependencies beyond the standard library.

Quick start

pip install psa-cli                       # package is psa-cli; command is psa
psa install 3.13                          # newest 3.13.x: download, extract, link
echo 'eval "$(psa shellenv)"' >> ~/.zshrc # put ~/.python/bin on PATH
python3.13 -m venv .venv                  # projects take it from there

psa install maintains symlinks in ~/.python/bin: python3.X per installed minor (newest patch wins), and python3 pointing at the highest minor — or a pinned one via psa link --set-default 3.12.

Or without installing:

python -m psa install 3.13

Optional extra for in-Python extraction of .tar.zstd without a zstd-capable system tar:

pip install "psa-cli[extract]"

Layout

Base directory defaults to ~/.python (override with --base-dir):

~/.python/
  downloads/            # raw downloaded archives
  versions/<version>/   # extracted trees
  bin/                  # managed symlinks (python3, python3.X)
  config.toml           # optional settings (default = "3.X")

Documentation

Full command reference lives in docs/ (Sphinx):

pip install -e ".[docs]"
sphinx-build -M html docs docs/_build

Project structure

src/psa/
  cli.py        # argparse commands
  releases.py   # remote: release metadata, asset parsing, downloads
  store.py      # local: extraction, installed versions, symlinks, config
tests/          # pytest suite (offline pieces: parsing, selection, linking)
docs/           # Sphinx documentation
notes/          # design notes and history

Tests

python -m pytest

License

MIT