Does it work in the presence and (ab)use of dynamic features? (e.g., when you have lots of decorated functions) Or is it just a best effort thing? (i.e., only works when your code would actually be expressible in a static way)

This is a continuum... in many statically typed languages there are regularly used paths that lead outside the realm of the language-defined type system as well. Consider dynamic class loading in Java, dlopen / reinterpret_cast in C++ etc.

> This is a continuum.

It is not. A language feature is either amenable to static analysis (not necessarily type checking) or it is not.

> Consider dynamic class loading in Java, dlopen / reinterpret_cast in C++ etc.

This actually emphasizes my point. Features that are not amenable to static analysis are problematic for tooling.

You mean there’s an ide with that feature? It’s never as good as with any statically type language.

Sublime Text has this feature on hover, but I am fairly certain it is based on text search of the modules in the python path.

Have you tried it? It's usually pretty good for Python.

Which IDE?

PyCharm and VSCode are both pretty good.