Modern Python tooling and best practices using uv, ruff, ty, and pytest. Based on patterns from trailofbits/cookiecutter-python.
Author: William Tan
- Setting up a new Python project with modern, fast tooling
- Replacing pip/virtualenv with uv for faster dependency management
- Replacing flake8/black/isort with ruff for unified linting and formatting
- Replacing mypy with ty for faster type checking
- Adding pre-commit hooks and security scanning to an existing project
Core Tools:
- uv - Package/dependency management (replaces pip, virtualenv, pip-tools, pipx, pyenv)
- ruff - Linting and formatting (replaces flake8, black, isort, pyupgrade)
- ty - Type checking (replaces mypy, pyright)
- pytest - Testing with coverage enforcement
- prek - Pre-commit hooks (replaces pre-commit)
Security Tools:
- shellcheck - Shell script linting
- detect-secrets - Secret detection in commits
- actionlint - GitHub Actions syntax validation
- zizmor - GitHub Actions security audit
- pip-audit - Dependency vulnerability scanning
- Dependabot - Automated dependency updates with supply chain protection
Standards:
- pyproject.toml - Single configuration file with dependency groups (PEP 735)
- PEP 723 - Inline script metadata for single-file scripts
- src/ layout - Standard package structure
- Python 3.11+ - Minimum version requirement
This plugin includes a SessionStart hook that prepends PATH shims for python, pip, pipx, and uv. When Claude runs a bare python, pip, or pipx command, the shell resolves to the shim, which prints an error with the correct uv alternative and exits non-zero. The suggested alternative always uses the exact command name python (never python3) so it also works outside a project; see the header comment in hooks/shims/python for the full rationale.
The shims sit on PATH, so they see every subprocess a tool spawns, not only what Claude types. That is why the intercepted set is narrow: it covers the invocations uv run and uv add genuinely replace, and passes the rest through to the real binary. python -c, python -m <module> and python - read a program from the command line, an installed module, or stdin, so none of them resolves a script against a project's dependencies; uv pip carrying --project, --directory or --target is a tool building an environment it owns. Redirecting those broke real tooling, including prek hook installation and any script piping into python3 - (#207).
| Intercepted Command | Suggested Alternative |
|---|---|
python ... |
uv run python ... |
python -m pip |
uv add/uv remove |
pip install pkg |
uv add pkg or uv run --with pkg |
pip uninstall pkg |
uv remove pkg |
pip freeze |
uv export |
uv pip ... |
uv add/uv remove/uv sync |
| (passed through) | python -c, python -m <module>, python -, and uv pip with --project, --directory or --target |
pipx install <pkg> |
uv tool install <pkg> |
pipx run <pkg> |
uvx <pkg> |
pipx uninstall <pkg> |
uv tool uninstall <pkg> |
pipx upgrade <pkg> |
uv tool upgrade <pkg> |
pipx upgrade-all |
uv tool upgrade --all |
pipx ensurepath |
uv tool update-shell |
pipx inject <pkg> <dep> |
uv tool install --with <dep> <pkg> |
pipx list |
uv tool list |
Commands like grep python, which python, and cat python.txt work normally because python is a shell argument, not the command being invoked.
/plugin install trailofbits/skills/plugins/modern-python