Python Tutorial: Type Hinting vs Type Checking vs Data Validation - What’s the Difference?

Python developers often confuse type hinting, type checking, and data validation. Type hints add metadata to code for documentation and IDE support but aren't enforced at runtime. Type checking uses tools like mypy to analyze code before execution and catch type mismatches early. Data validation happens at runtime to verify data meets requirements, with libraries like Pydantic automating this process using type hints. Each serves different purposes: hints improve code readability, checking catches errors during development, and validation protects against bad external data.