Python Formatting

Python Formatting

Use When

• Setting up or validating code formatting for Python projects.
• Configuring Black and isort for consistent style.
• Integrating formatting into IDE or pre-commit hooks.

Standard Formatters

1. Black (recommended for Python)

• Opinionated, minimal configuration, fast.
• Enforces PEP 8 with specific style choices (88-char line width).
• Install: pip install black.

1. isort (import sorting)

• Organizes imports into sections (stdlib, third-party, local).
• Integrates with Black.
• Install: pip install isort.

1. Ruff (optional, fast linter and formatter)

• Modern, Rust-based; superset of some Black functionality.
• Can format and lint in one pass.
• Install: pip install ruff.

Configuration

pyproject.toml (Black and isort):

[tool.black]
line-length = 88
target-version = ['py39', 'py310', 'py311']

[tool.isort]
profile = "black"
line_length = 88
skip_glob = [".venv", "venv"]

.flake8 or pyproject.toml (linting):

[tool.flake8]
max-line-length = 88
exclude = [".venv", "venv", ".git"]

VS Code .vscode/settings.json:

{
  "[python]": {
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "ms-python.python",
    "editor.codeActionsOnSave": {
      "source.organizeImports": true
    }
  },
  "python.formatting.provider": "black",
  "python.linting.enabled": true,
  "python.linting.flake8Enabled": true
}

Checklist

1. Consistency

• Black is installed and configured via pyproject.toml.
• isort is configured with profile = "black" to avoid conflicts.
• Configuration is version-controlled and shared with team.

1. IDE integration

• Format-on-save is enabled in VS Code.
• Python extension is installed and active.

1. Pre-commit hooks

• Use pre-commit framework with Black and isort hooks.
• Prevents unformatted code from entering the repository.

1. Import organization

• isort sorts imports into stdlib, third-party, local sections.
• Multi-line imports are handled consistently.

Formatting Rules

• Line width: 88 characters (Black standard).
• Indentation: 4 spaces (PEP 8).
• String quotes: Double quotes (customizable, Black default).
• Trailing commas: Used for multi-line structures.
• Import order: Stdlib, third-party, local (isort).

Common Commands

• Format: black src/.
• Sort imports: isort src/.
• Check: black --check src/ or isort --check src/.
• Combined: black src/ && isort src/.

Output Requirements

When setting up or validating formatting, provide:

• Formatter versions and configuration.
• IDE integration status.
• Pre-commit hook setup summary.
• Any conflicts or inconsistencies found.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: caraya
• Source: caraya/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.