pipx: isolated command line tools

Application is not a library

A library (requests, for example) you use within your code, so it resides in the project's venv. A command-line tool (ruff, poetry, httpie) you run in the terminal anywhere. Installing this with pip globally pollutes Python and causes conflicts. Pipx creates a venv for each tool and exposes only the command.

Installation

brew install pipx
pipx ensurepath

The pipx ensurepath adds the pipx executables folder to your PATH. Close and reopen the terminal afterwards.

Everyday use

pipx install ruff
pipx list
pipx upgrade ruff
pipx upgrade-all
pipx uninstall ruff

To run a tool just once, without installing, use pipx run. It lives in a temporary environment:

pipx run ruff --version

To choose the version of Python that the tool uses:

pipx install --python 3.13 ruff

To add a plugin to the environment of an already installed tool, use pipx inject:

pipx inject poetry poetry-plugin-export

Which tools are in your PATH

The module shutil helps to see, from Python, what is installed and where:

import shutil

for ferramenta in ["python3", "pipx", "uv", "poetry", "pyenv"]:
    caminho = shutil.which(ferramenta)
    situacao = f"instalado em {caminho}" if caminho else "não encontrado"
    print(f"{ferramenta:8} {situacao}")

python3  instalado em /opt/homebrew/bin/python3
pipx     instalado em /Users/ana/.local/bin/pipx
uv       instalado em /Users/ana/.local/bin/uv
poetry   instalado em /Users/ana/.local/bin/poetry
pyenv    não encontrado

The block above is an example. Its output depends on what you have installed.

The uv serves the same purpose

The command uv tool install ruff is equivalent to pipx install ruff, and uvx is equivalent to pipx run. If you adopt uv (chapter 7), you can skip pipx.