PEP 827 – Type Manipulation
Summary
PEP 827 proposes powerful type-level introspection and construction facilities for Python's typing system, inspired by TypeScript features like conditional and mapped types. It outlines primitives such as type booleans, conditional types, unpacked comprehensions, and extended callables, plus runtime evaluation hooks and a range of practical examples including Prisma-style ORMs and FastAPI CRUD model derivations. The proposal is still in draft, aiming to improve static typing for metaprogramming and framework development.