Python Build Tools Skill

Python Build Tools

Modern Python development tooling using uv, mise, ruff, basedpyright, and pytest.

Quick Start

Minimal pyproject.toml

[project]
name = "my-project"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = ["fastapi", "pydantic"]

[project.optional-dependencies]
dev = ["pytest>=8.0.0", "ruff>=0.8.0", "basedpyright>=1.0.0"]

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[tool.ruff]
target-version = "py312"

[tool.ruff.lint]
select = ["E", "F", "I", "N", "UP", "RUF"]

[tool.basedpyright]
typeCheckingMode = "strict"

[tool.pytest.ini_options]
testpaths = ["tests"]

Setup Project

uv init my-project && cd my-project
uv sync
uv add fastapi pydantic
uv add --dev pytest ruff basedpyright

Tool Overview

| Tool | Purpose | Replaces | |------|---------|----------| | uv | Package management | pip, virtualenv | | mise | Version & tasks | pyenv, asdf | | ruff | Lint & format | black, isort, flake8 | | basedpyright | Type checking | mypy | | pytest | Testing | unittest |

Common Commands

Lint and Format

uv run ruff check --fix .
uv run ruff format .

Type Check

uv run basedpyright
uv run basedpyright src/main.py

Test

uv run pytest
uv run pytest --cov=src --cov-report=html

Manage Dependencies

uv add fastapi
uv add --dev pytest
uv lock --upgrade
uv tree

Mise Configuration

Create .mise.toml for consistent development:

[tools]
python = "3.12"

[tasks.lint]
run = "uv run ruff check --fix ."

[tasks.format]
run = "uv run ruff format ."

[tasks.typecheck]
run = "uv run basedpyright"

[tasks.test]
run = "uv run pytest"

[tasks.check]
depends = ["lint", "format", "typecheck", "test"]

Usage:

mise install
mise run check

Type Hints Example

from decimal import Decimal
from typing import Optional

def calculate_discount(
    total: Decimal,
    rate: Optional[Decimal] = None
) -> Decimal:
    if rate is None:
        rate = Decimal("0.1")
    return total * rate

Best Practices

Use uv for all package management (faster, reliable)
Pin Python version with mise
Configure tools in pyproject.toml
Enable strict type checking
Run checks before commit

References

For detailed configuration and advanced patterns:

references/uv.md - Workspaces, scripts, dependency management
references/ruff.md - Rules, per-file ignores, pre-commit integration
references/basedpyright.md - Type patterns, generics, protocols

Agent Skills: Python Build Tools

Install this agent skill to your local

Skill Files