I too see potential in this - it started feeling a bit weird in recent years switching between Go, Python and Rust codebases with Python code looking more and more like a traditional statically typed language and not getting the performance benefits. I know I know, there are libraries and frameworks which make heavy use of fun stuff you can do with strings (leading to the breakdown of even the latest and greatest IDE tooling and red squiggly lines all over you code) and don’t get me started on async etc.

Funnily enough I’ve found Python to be excellent for modelling my problem domain with Pydantic (so far basically unparalleled, open for suggestions in Go/Rust), while the language also gets out of my way when I get creative with list expressions and the like. So overall, still it is extremely productive for the work I’m doing, I just need to spin up more containers in prod.

> A Python4 that actually used typing in the interpreter, had value types, had a comptime phase to allow most metaprogramming to work (like monkey patching for tests) would be great! It would be faster, cleaner, easier to reason about, and still retain the great syntax and flexibility of the language.

And what prevents someone from designing such a language?

Any program written in Python of any significant size is literally a soup of multiple languages.

I’d like to be good looking and drive a Ferrari. But that probably isn’t going to happen, either.

Me too, but changing the referential semantics would be a massive breaking change. That doesn't qualify as "without changing much of a codebade". And tacking on a giant new orthogonal type system to avoid breaking existing code would be akin to creating a new language. Why bother when you can just write Python modules in Rust.