[lsh]

Python type hinting and aliases in Python 3: https://docs.python.org/3/library/typing.html

I've just finished porting a small application to Python 3 just because 2020 and deprecation is in sight already - there are so many things that have passed me by in the Py3 world.

[kzrdude]

What I missed first was this deal with provisional API. Nice that it's widely tested, but it should be clear that typing is provisional: Your program is not future compatible if you use it.

Asyncio was provisional until Python 3.6, so it is effectively a Py 3.6 feature that has been backported to 3.5 in time and space.