PyType - Advanced Python Static Type Checker

A clean, modular, and extensible Python static type checker designed for modern Python development.

🚀 Features

• Static Type Checking: Parse and analyze .py files for type annotations
• Type Inference: Infer variable and return types using AST analysis
• CLI Tool: Easy-to-use command-line interface with rich options
• Modular Architecture: Clean separation of concerns with extensible design
• Rich Error Reporting: Colored CLI output and JSON export for CI/CD
• Configuration Support: TOML-based configuration files

📦 Installation

From Source

git clone https://github.com/engmaryamameen/pytype.git
cd pytype
pip install -e .

Development Installation

pip install -e ".[dev]"

🛠️ Usage

Basic Usage

# Check a single file
pytype myfile.py

# Check a directory
pytype myproject/

# Show inferred types
pytype --infer myfile.py

# Auto-fix with inferred types
pytype --fix myfile.py

# Strict mode (treat missing types as errors)
pytype --strict myfile.py

# JSON output for CI/CD
pytype --format=json myfile.py

# Use custom config
pytype --config=pytype.toml myfile.py

Configuration File

Create a pytype.toml file in your project root:

[tool.pytype]
strict = false
infer = true
fix = false
format = "text"
exclude = ["tests/", "migrations/"]
ignore_errors = ["E501", "F401"]

🏗️ Architecture

PyType follows a layered, modular architecture:

pytype/
├── __init__.py     # Package initialization and exports
├── cli.py          # Command-line interface and argument parsing
├── checker.py      # Core type checking logic
├── infer.py        # Type inference engine
├── analyzer.py     # AST parsing and analysis
├── config.py       # Configuration management
└── reporter.py     # Error reporting and output formatting

Core Components

• cli.py: Command-line interface and argument parsing
• checker.py: Handles type checking logic and validation
• infer.py: Performs type inference on unannotated code
• analyzer.py: AST parsing and semantic analysis
• reporter.py: Formats and outputs errors and warnings
• config.py: Manages configuration loading and validation

🧪 Testing

Run the test suite:

# Run all tests
pytest

# Run with coverage
pytest --cov=pytype

# Run specific test file
pytest tests/test_checker.py

🔧 Development

Code Quality

This project uses several tools to maintain code quality:

• Black: Code formatting
• Ruff: Linting and import sorting
• Pytest: Testing framework
• Coverage: Test coverage reporting

Pre-commit Setup

# Install pre-commit hooks
pre-commit install

# Run all hooks
pre-commit run --all-files

📝 Example Output

Text Format

[ERROR] myfile.py:12: Expected int, got str in function 'add'
[WARNING] myfile.py:25: Missing return type annotation for function 'process_data'
[INFO] myfile.py:30: Inferred type: List[str] for variable 'items'

JSON Format

{"file": "myfile.py", "line": 12, "message": "Expected int, got str in function 'add'", "type": "type_mismatch", "severity": "error"}

🤝 Contributing

We welcome contributions! Here's how you can help:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Development Setup

# Clone and install in development mode
git clone https://github.com/engmaryamameen/pytype.git
cd pytype
pip install -e ".[dev]"

# Run tests
pytest

# Run linting
ruff check .

# Format code
black .

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

💖 Support This Project

If you find PyType helpful and would like to support its development, consider:

☕ Buy Me a Coffee

⭐ Star the Repository

If you can't contribute financially, starring this repository helps a lot!

🐛 Report Issues

Found a bug? Have a feature request? Open an issue!

📝 Improve Documentation

Help improve the documentation or add examples!

👥 Contributors

Thanks goes to these wonderful people:

engmaryamameen 🚀 Project Creator & Maintainer

This project follows the all-contributors specification. Contributions of any kind welcome!

🙏 Acknowledgments

• Inspired by tools like mypy, pyright, and Google's pytype
• Built with modern Python best practices
• Designed for extensibility and maintainability

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Thank you for your support! 🚀