| 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:
- Pass the URL directly to the
git:shallow-clone skill
- Search for LICENSE files in the cloned repository (see Step 2.3-2.4 below)
- 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:
- Get the source repository URL from the PyPI metadata (the script will provide it)
- Use the shallow-clone skill to clone the repository:
Skill: git:shallow-clone
- Search for LICENSE files in the cloned repository:
find . -iname "license*" -o -iname "copying*" -o -iname "copyright*" | head -10
- 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.
