Python Type Hints Guide

Purpose

This skill provides comprehensive guidance on Python type hints and static type checking for Python 3.9+ codebases. It serves as a reference during code reviews to ensure proper type annotation usage, evaluate type hint quality, and promote best practices for gradual typing adoption.

This skill should be referenced by the uncle-duke-python agent when:

• Reviewing Python code for type hint usage
• Evaluating type annotation quality and consistency
• Identifying type hint anti-patterns
• Recommending mypy configuration improvements
• Guiding gradual typing adoption strategies

Context

Type hints (introduced in PEP 484) enable static type checking in Python while maintaining the language's dynamic nature. Modern Python (3.9+) has significantly improved type hint syntax with built-in generic types and the union operator. Proper type hints improve: