Python License

One command to add SPDX license headers to all your source files. Works best with pre-commit hooks.

What It Does

Automatically adds SPDX-compliant license headers to your source files.

For Python files:

# SPDX-License-Identifier: Apache-2.0
# Copyright (C) 2025  Your Name

def your_code():
    pass

For JavaScript/TypeScript/Go/Rust:

// SPDX-License-Identifier: MIT
// Copyright (C) 2025  Your Company

function yourCode() {}

For CSS/HTML:

/* SPDX-License-Identifier: Apache-2.0 */
/* Copyright (C) 2025  Your Name */

body { margin: 0; }

Key Features

• Supports 50+ file types including Python, JavaScript, TypeScript, Go, Rust, Java, C/C++, Swift, Kotlin, Ruby, Shell, SQL, and more
• Automatically updates copyright year ranges (e.g., 2023 becomes 2023-2025 when modified)
• Check mode for CI/CD integration to ensure all files have headers
• Respects .licenseignore and .gitignore files automatically
• Preserves shebang lines in executable scripts
• Handles multiple comment styles (hash, slash, dash, block comments)

Supported Languages

Hash comments (#): Python, Shell (bash/zsh/fish), Ruby, Perl, R, YAML, TOML, CMake

Slash comments (//): JavaScript, TypeScript, Go, Rust, Java, C/C++, Swift, Kotlin, C#, PHP, Scala, Objective-C, Gradle, Groovy, SCSS, Sass, Less

Dash comments (--): SQL, Lua, Haskell, Elm

Block comments: CSS (/* */), HTML/XML/SVG (<!-- -->)

Special files: Dockerfile, Makefile, Jenkinsfile, Vagrantfile, Rakefile, Gemfile, Podfile, Fastfile, CMakeLists.txt, and more

Installation

pipx install python-license

Or with pip:

pip install python-license

Usage

Command Line

Basic syntax:

license <license-id> "<author>" [options]

Examples:

# Check files without modifying (dry-run)
license Apache-2.0 "John Doe" --check

# Add/update headers in specific directory
license MIT "Jane Smith" --fix --dir src/

# Use custom ignore file
license GPL-3.0 "ACME Corp" --ignore-file .licenseignore --fix

# Process specific files only
license Apache-2.0 "Your Name" --fix file1.py file2.js

# Set custom copyright year
license MIT "Your Company" --fix --year 2024

Pre-commit Hook (Recommended)

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

repos:
  - repo: https://github.com/eznix86/python-license
    rev: v1.0.0
    hooks:
      - id: license-headers
        args: ['--check', 'Apache-2.0', 'Your Name']

For automatic fixing on commit:

repos:
  - repo: https://github.com/eznix86/python-license
    rev: v1.0.0
    hooks:
      - id: license-headers
        args: ['--fix', 'Apache-2.0', 'Your Name']

See .pre-commit-config.yaml for a complete example.

Options

Option	Description
--check	Check files without modifying (default mode)
--fix	Add or update headers in files
--dir DIR	Root directory to process (default: current directory)
--year YEAR	Copyright year (default: current year)
--no-recursive	Don't process subdirectories
--verbose, -v	Show all processed files
--ignore-file FILE	Path to ignore file (default: .licenseignore or .gitignore)
files	Specific files to process (overrides --dir)

Ignore Files

Create a .licenseignore file to exclude specific files or directories:

# Ignore patterns (similar to .gitignore)
*.min.js
*.min.css
generated/*
vendor/
third_party/
build/
dist/

# Negate patterns (don't ignore these)
!important.min.js

If no .licenseignore exists, the tool automatically uses .gitignore patterns.

See .licenseignore for an example.

FAQ

Does it overwrite existing headers?

No, it intelligently updates them. If a file already has an SPDX header, it will:

• Update the license identifier if changed
• Update the copyright year range (e.g., 2023 → 2023-2025)
• Preserve the existing header structure

How does it handle copyright years?

The tool automatically manages copyright year ranges:

• First added: Copyright (C) 2025 Your Name
• After modification in 2026: Copyright (C) 2025-2026 Your Name
• If already current: no change

Can I use it in CI/CD?

Yes! Use --check mode to fail the build if any files are missing headers:

# GitHub Actions example
- name: Check license headers
  run: license Apache-2.0 "Your Name" --check

This returns exit code 1 if any files need updating.

What files are excluded by default?

The tool automatically excludes common build artifacts and dependencies:

• Version control: .git/, .svn/, .hg/
• Dependencies: node_modules/, vendor/, third_party/
• Build outputs: build/, dist/, target/, __pycache__/
• Minified files: *.min.js, *.min.css
• Lock files: *.lock, *.sum, go.mod
• Config files: *.json, *.toml, *.yaml

Can I use custom SPDX license identifiers?

Yes! Use any valid SPDX license identifier. Common examples:

• MIT
• Apache-2.0
• GPL-3.0-or-later
• BSD-3-Clause
• ISC

See SPDX License List for all valid identifiers.

Does it work with monorepos?

Yes! You can:

• Run it on the entire repo
• Use --dir to target specific packages
• Use different .licenseignore files in different directories
• Process specific files only

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

This project is licensed under the Apache License 2.0.

See the NOTICE file for additional information.