definder

depfinder 🔍

A Python dependency analyzer inspired by Black's implementation that automatically discovers and extracts third-party imports from your Python projects. It scans your codebase to identify external dependencies while filtering out project-internal imports.

Features ✨

• Follows Black's approach to traverse Python files
• Smart package name resolution (e.g., PIL → pillow, cv2 → opencv-python)
• Filters out both standard library and project-internal imports
• Handles common import name mismatches
• Generates requirements.txt file
• Parallel processing for faster scanning

⚠️ Note: The tool may occasionally fail to identify some dependencies due to complex import patterns or dynamic imports.

Installation 📦

pip install depfinder

Usage 🚀

You can use depfinder either as a module or directly as a command (like Black):

# As a command (recommended)
definder src/
definder .                    # Current directory
definder src/ tests/         # Multiple paths

# As a module
python -m definder src/
python -m definder .

Options:

definder src/ --no-save     # Don't generate requirements file
definder src/ --workers 4   # Specify number of parallel workers

How it Works 🛠️

1. Traverses Python files using Black's file discovery approach
2. Uses AST parsing to safely extract imports
3. Filters out standard library and project-internal imports
4. Maps common import aliases to their correct PyPI package names
5. Generates a clean requirements file

Output 📝

The tool will:

1. Show all scanned files
2. List discovered third-party dependencies
3. Generate a requirements.txt file (or requirements-definder.txt if the former exists)

Known Limitations 🚧

• May not detect dependencies from dynamic imports
• Some complex import patterns might be missed
• Package name mapping might not cover all cases

Contributing 🤝

Found a bug or want to improve the package name mapping? Contributions are welcome! Please feel free to submit a Pull Request.

License 📄

MIT