python-packaging-license-finder

name	python-packaging-license-finder
description	Use this skill to deterministically find license information for Python packages by checking PyPI metadata first, then falling back to Git repository LICENSE files using shallow cloning.
allowed-tools	Bash Skill

Python Package License Finder

This skill helps you deterministically find license information for Python packages using a two-step approach: first checking PyPI metadata, then searching the source repository if needed.

Instructions

When a user asks to find the license for a Python package, follow this deterministic process:

Step 0: Source URL Priority

If a source repository URL is provided by the caller, skip PyPI lookup entirely:

1. Pass the URL directly to the git:shallow-clone skill
2. Search for LICENSE files in the cloned repository (see Step 2.3-2.4 below)
3. Report the license found

You can also use the script with a source URL to trigger this flow:

./scripts/find_license.py <package_name> --source-url <url>

If no source URL is provided, proceed with Step 1.

Step 1: Check PyPI Metadata

First, attempt to find the license from PyPI using the package inspection script:

./scripts/find_license.py <package_name> [version]

If the script finds a license in the PyPI metadata, stop here and return the license name.

Step 2: Search Git Repository (if PyPI fails)

If no license is found in PyPI metadata, search the package's source repository:

1. Get the source repository URL from the PyPI metadata (the script will provide it)
2. Use the shallow-clone skill to clone the repository:

   Skill: git:shallow-clone
   

3. Search for LICENSE files in the cloned repository:

   find . -iname "license*" -o -iname "copying*" -o -iname "copyright*" | head -10
   

4. Read the license file to identify the license type:

   head -20 <license_file>
   

Step 3: Report Results

• License Found: Return the license name (e.g., "MIT License", "Apache-2.0", "GPL-3.0")
• License Not Found: Report that the license could not be determined

Usage Examples

Find License for Popular Package

./scripts/find_license.py requests

Expected: Find "Apache-2.0" from PyPI metadata

Find License for Package with Missing PyPI License

./scripts/find_license.py some-package

Expected: Fall back to repository search if PyPI metadata is incomplete

Specific Version Analysis

./scripts/find_license.py django 4.2.0

Expected: Find license for specific Django version

Error Handling

Package Not Found

• Verify package name spelling
• Check package availability on PyPI
• Suggest alternative package names

Repository Access Issues

• Report if source repository is unavailable
• Note private/restricted repositories
• Suggest manual license verification

License File Parsing

• Handle non-standard license file formats
• Report unclear or multiple licenses
• Recommend manual review for complex cases

Integration Notes

This skill complements:

• python-packaging-complexity - License info helps assess redistribution complexity
• python-packaging-license-checker - Provides license names for compatibility assessment
• python-packaging-source-finder - Uses similar PyPI metadata analysis

The skill focuses on finding license information, while license-checker focuses on assessing license compatibility for redistribution.