Python Cookbook

This repository contains a collection of Python projects that exemplify common operations and design patterns in Python. It serves as a quick reference guide with practical examples (recipes) of how to implement frequently used libraries and design patterns in Python 3.11+.

Recipes

Design Patterns

• The Strategy Pattern
• The Factory Pattern
• The Builder Pattern
• The Observable Pattern

Beginner Topics

• Generics in Python
• Reading and writing JSON
• Reading and writing YAML
• Handling HTTP Requests
• Data classes
• Error Handling and Logging
• Context Managers (with statement)
• Decorators

Intermediate Topics

• Reading and writing from/to Postgres
• Reading and writing from/to MongoDB
• Reading and writing from/to Redis
• Type Hinting and Static Type Checking
• Functional Programming
• Packaging and Distribution
• API Development with FastAPI
• Concurrent Processing (Threading vs Multiprocessing)
• Property-Based Testing
• Event-Driven Programming

Advanced Topics

• Asynchronous Programming (asyncio)
• Metaprogramming
• Performance Optimization
• Memory Management
• Cython Integration

Project Structure

Each recipe follows a consistent structure:

.
├── <pattern_name>/
│   ├── README.md
│   ├── <pattern_name>/
│   ├── tests/
│   ├── main.py
│   └── requirements.txt

Where:

• README.md contains detailed notes about the recipe, including implementation details and usage examples
• main.py provides a demonstration of the pattern in action
• tests/ contains unit tests that validate the implementation

Development Setup

Requirements

• Python 3.11+
• pip (Python package installer)
• Go Task (optional, for task automation)

Getting Started

1. Clone the repository
2. Install development dependencies:

   pip install -r requirements-dev.txt

3. Set up Git hooks (optional, but recommended):

   ./hooks/install-hooks.sh

Task Automation

This project uses Go Task to automate common development tasks:

• task setup-root-venv: Creates and sets up the root virtual environment
• task setup-recipe-venv RECIPE=<name>: Sets up a recipe-specific virtual environment
• task format RECIPE=<name>: Formats code using black
• task lint RECIPE=<name>: Runs flake8 linting
• task test RECIPE=<name>: Runs tests for a specific recipe
• task validate-recipe RECIPE=<name>: Runs format, lint, and test for a recipe
• task validate-all: Validates all recipes in the repository

Code Quality

This project uses several tools to maintain code quality:

• black: Code formatting
• flake8: Code linting
• pytest: Testing framework
• pytest-cov: Test coverage reporting

Git Hooks

• pre-commit: Runs black and flake8 on staged Python files
• pre-push: Runs tests for modified recipes before pushing

Continuous Integration

The project uses GitHub Actions for CI, which runs on every push to main and pull requests:

• Runs tests against Python 3.11 and 3.12
• Enforces code formatting with black
• Runs linting with flake8
• Requires 70% test coverage
• Reports coverage to Codecov with component-based tracking:
  • Each recipe is tracked as a separate component
  • Cross-cutting components for tests and core implementations
  • Coverage status displayed in PR comments