Well this is anything but a new complaint. I would assume a user who has worked in Python for some modest amount of time to have made peace with this. One works

Well this is anything but a new complaint. I would assume a user who has worked in Python for some modest amount of time to have made peace with this. One works in Python knowing that this can and will happen (well one does have linter on steroid like mypy now to counter these). Python code needs more testing, more run time type checking of function arguments than a statically typed language. If that's a deal-breaker then one shouldn't be using Python in the first place. What you gain though is some instant gratification, and the ability to get something off the ground quickly without spending time placating the type checker. Its great where your workflow involves lot of prototyping, exploration of the solution space and interactive use (ML comes to mind, but even there int32 vs int64 can byte, correction, bite). I see it as a trade off -- deferring one kind of work (ensuring type safety) over another. Hopefully that deferral is not forever. I like my type safety but sometimes I want that later. What I typically do is once I am happy with a module and I do not need the extreme form of dynamism that Python offers (something that's frequently true) I take away that dynamism by compiling those parts with Cython.