PolyBus Python

A Python implementation of the PolyBus messaging library, providing a unified interface for message transport across different messaging systems.

Prerequisites

• Python 3.8+ (supports Python 3.8-3.12)
• pip (Python package installer)
• Any IDE that supports Python development (VS Code, PyCharm, etc.)

Quick Start

Setting Up Development Environment

# Navigate to the python directory
cd src/python

# The project uses a virtual environment at the repo root
# It should already be configured by VS Code
# If needed, activate it:
source ../../.venv/bin/activate  # On Windows: ..\..\\.venv\Scripts\activate

# Install the package in development mode with dev dependencies
pip install -e ".[dev]"
# Or use the dev script with PYTHON env var:
# PYTHON=../../.venv/bin/python ./dev.sh install

Building the Project

# Install dependencies and package
./dev.sh install

# Build the package
./dev.sh build

Running Tests

# Activate virtual environment first
source ../../.venv/bin/activate  # On Windows: .venv\Scripts\activate

# Run all tests
python -m pytest
# Or: ./dev.sh test (if PYTHON env var is set)

# Run tests with coverage
python -m pytest --cov=src --cov-report=html --cov-report=term
# Or: ./dev.sh test-cov

# Run specific test files
python -m pytest tests/test_poly_bus.py

# Run tests with verbose output
python -m pytest -v

# Run tests matching a pattern
python -m pytest -k "test_pattern"

Development Workflow

Code Quality and Linting

This project includes comprehensive code analysis and formatting tools:

# Run the complete development check suite
./dev.sh check

# Format code automatically
./dev.sh format

# Run linters only
./dev.sh lint

# Individual tools:
python -m black src tests          # Code formatting
python -m isort src tests          # Import sorting
python -m flake8 src tests         # Style checking
python -m mypy src                 # Type checking

IDE Integration

Visual Studio Code

1. Install the Python extension
2. Install Python development extensions (Black, isort, Flake8, mypy)
3. Open the src/python folder in VS Code
4. The project includes configuration for auto-formatting and linting

PyCharm

1. Open the src/python folder as a project
2. Configure the virtual environment as the project interpreter
3. Enable code inspections and formatting tools

Configuration

Project Configuration

The project uses pyproject.toml for modern Python packaging:

• Python Version: 3.8+ (supports 3.8-3.12)
• Build System: setuptools
• Testing: pytest with coverage
• Code Quality: black, isort, flake8, mypy
• Package Structure: src layout

Code Style

Code style is enforced through:

• Black (88 character line length)
• isort (import sorting with black profile)
• flake8 (PEP 8 compliance)
• mypy (type checking with strict settings)

Testing Configuration

Pytest configuration includes:

• Coverage reporting (HTML, XML, terminal)
• Strict marker and config validation
• Support for async tests (pytest-asyncio)
• Test discovery patterns

Dependencies

Runtime Dependencies

• No runtime dependencies (pure Python implementation)

Development Dependencies

• pytest>=7.0.0 - Testing framework
• pytest-cov>=4.0.0 - Coverage reporting
• pytest-asyncio>=0.21.0 - Async test support
• black>=23.0.0 - Code formatting
• isort>=5.12.0 - Import sorting
• flake8>=6.0.0 - Style checking
• mypy>=1.0.0 - Type checking

Common Commands

# Development script commands
./dev.sh install     # Install in development mode
./dev.sh test         # Run tests
./dev.sh test-cov     # Run tests with coverage
./dev.sh lint         # Run all linters
./dev.sh format       # Format code
./dev.sh check        # Run all checks (format + lint + test)
./dev.sh clean        # Clean build artifacts
./dev.sh build        # Build package
./dev.sh help         # Show all available commands

# Direct pytest commands
python -m pytest                             # Run all tests
python -m pytest --cov-report=html           # Generate HTML coverage report
python -m pytest tests/example.py            # Run specific test file
python -m pytest -x                          # Stop on first failure
python -m pytest --lf                        # Run last failed tests only

# Package management
pip install -e ".[dev]"                      # Install in development mode
pip install -r requirements-dev.txt          # Install dev dependencies only
python -m build                              # Build wheel and source distribution

Troubleshooting

Environment Issues

1. Python Version: Ensure Python 3.8+ is installed

   python3 --version
   

2. Virtual Environment: Always use a virtual environment

   python3 -m venv venv
   source venv/bin/activate
   

3. Package Installation Issues: Upgrade pip and setuptools

   pip install --upgrade pip setuptools wheel
   

Test Issues

1. Import Errors: Ensure package is installed in development mode

   pip install -e ".[dev]"
   

2. Coverage Issues: Check that source paths are correct in pyproject.toml

3. Type Checking Issues: mypy configuration is strict; add type annotations as needed

Code Quality Issues

1. Formatting: Run ./dev.sh format to auto-fix most formatting issues
2. Import Order: isort will automatically fix import ordering
3. Type Errors: Add proper type annotations for mypy compliance

Contributing

1. Follow the established code style (enforced by formatters and linters)
2. Run ./dev.sh check before committing
3. Ensure all tests pass and maintain high coverage
4. Add tests for new functionality
5. Add type annotations for all new code
6. Update documentation as needed

Coverage Reports

After running tests with coverage (./dev.sh test-cov):

• Terminal: Coverage summary displayed in terminal
• HTML: Detailed report available in htmlcov/index.html
• XML: Machine-readable report in coverage.xml

Additional Resources

• Python Packaging Guide
• pytest Documentation
• Black Code Formatter
• mypy Type Checking

License

See the main project LICENSE file for licensing information.