[imiric]

Python has optional typing support in the standard library since version 3.5. Granted, not type _checking_, but that is offloaded to external tools like mypy[0].

I feel that gradual typing offers the best of both worlds: rapid prototyping, but also the strictness of types where you need it.

0: http://mypy-lang.org/

[trentmc]

Good point! I think the Python folks made a great design choice there. I updated my comment above to help future readers.