Baby's First Type Checker: A 350-Line Python Adventure

This article details the creation of a basic type checker for Python in just 350 lines of code. The author walks through the process, from parsing Python code and finding type annotations to checking type compatibility, handling function calls and return types, supporting lists, dictionaries, and union types, and implementing type narrowing. While limited in scope, the resulting type checker successfully catches several type errors in real-world Python code, providing a clear and accessible example of how type checkers work.