Ruff Python Linter & Formatter

Use Ruff to lint and format Python code. Ruff is an extremely fast Python linter and code formatter written in Rust, providing 10-100x faster performance than existing tools like Flake8 and Black.

What This Skill Does

This skill helps you integrate Ruff into Python projects for:

Installation

Choose your preferred installation method:

**With uvx (no installation):**

```bash

uvx ruff check

uvx ruff format

```

**With uv (recommended):**

```bash

uv tool install ruff@latest # Install globally

uv add --dev ruff # Or add to project

```

**With pip:**

```bash

pip install ruff

```

**With pipx:**

```bash

pipx install ruff

```

**Standalone installer (macOS/Linux):**

```bash

curl -LsSf https://astral.sh/ruff/install.sh | sh

```

**Standalone installer (Windows):**

```powershell

powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"

```

Usage Instructions

Linting

Run Ruff as a linter to check for code quality issues:

```bash

Lint all files in current directory

ruff check

Lint specific directory

ruff check path/to/code/

Lint specific files

ruff check path/to/code/*.py

Lint with automatic fixes

ruff check --fix

Lint and show rule codes

ruff check --output-format=full

```

Formatting

Run Ruff as a formatter to auto-format code:

```bash

Format all files in current directory

ruff format

Format specific directory

ruff format path/to/code/

Format specific files

ruff format path/to/code/*.py

Check formatting without making changes

ruff format --check

```

Configuration

Create a `ruff.toml` or add to `pyproject.toml`:

```toml

ruff.toml

line-length = 88

target-version = "py39"

[lint]

select = ["E4", "E7", "E9", "F"] # Enable rule sets

ignore = [] # Ignore specific rules

fixable = ["ALL"]

unfixable = []

[format]

quote-style = "double"

indent-style = "space"

```

Or in `pyproject.toml`:

```toml

[tool.ruff]

line-length = 88

target-version = "py39"

[tool.ruff.lint]

select = ["E4", "E7", "E9", "F"]

ignore = []

```

Command-Line Configuration

Pass configuration via CLI arguments:

```bash

Enable specific rules

ruff check --select F401 --select F403

Ignore specific rules

ruff check --ignore E501

Configure via catch-all argument

ruff check --config "lint.per-file-ignores = {'some_file.py' = ['F841']}"

```

Pre-commit Integration

Add to `.pre-commit-config.yaml`:

```yaml

rev: v0.14.14

hooks:

- id: ruff-check

args: [ --fix ]

- id: ruff-format

```

GitHub Actions Integration

Add to `.github/workflows/ruff.yml`:

```yaml

name: Ruff

on: [ push, pull_request ]

jobs:

ruff:

runs-on: ubuntu-latest

steps:

- uses: actions/checkout@v4

- uses: astral-sh/ruff-action@v3

```

Common Use Cases

**Replace multiple tools:**

**Enable preview mode for latest features:**

```bash

ruff check --preview

```

Or in config:

```toml

[tool.ruff]

preview = true

```

**Per-file rule ignoring:**

```toml

[tool.ruff.lint.per-file-ignores]

"__init__.py" = ["F401"] # Allow unused imports in __init__.py

"tests/*.py" = ["S101"] # Allow assert in tests

```

**Customize rule selection:**

```bash

Enable all rules from specific categories

ruff check --select E,F,W,C,N

Enable all rules except specific ones

ruff check --select ALL --ignore E501,F401

```

Important Notes

Documentation