I do not see the benefit of type hints. Good docstrings (and naming of the function and arguments) are superior, at least for the human.
Type hints are too much clutter.
Any sufficiently detailed python docstring contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of a type annotation.
climb(thing): '''Climb a thing with steps''' # prevent run time crash: if not hasattr(thing, 'getSteps'): hitDeveloper()
Thanks to you and baq!
Once you make that big scary change you might have to rerun your unit tests dozens of times before you've found and fixed all of the bugs that your change caused.
A static type checker, plus a bit of foresight and diligence, will give you a much more complete view of the carnage up front, so that you have a good idea about the cost of making that change while it's still cheap to decide differently.
And the best part is that with python you can only bother with the type hints where you need them (e.g. at the boundaries between teams)
And some libraries sould be better documented.
But the compile time error messages of C or C++ or Delphi most of the time do not deliver a shorter feedback loop, because they are generally ugly and hard to understand. And you should write tests in all languages, so static typing isn't a timesaver in that respect, too.