On Tue, 28 May 2019 at 04:37, Till <till.varoquaux@gmail.com> wrote:

I didn't implement any good helper function because I couldn't figure
out the idiomatic way to traverse type hints at runtime. It would be
very easy to add a "get_extras(t: typing.<Type>) -> Tuple[Any, ...]"
function. Would that work?

This reminds me about something I wanted to do for Python 3.8: there is an idea to add couple public helpers for introspection of typing objects.

For example `get_origin()` and `get_args()`. That would essentially just thin public wrappers around private `__origin__`/`__args__` API.

With such API one will be able to just write `if get_origin(typ) is Annotated: ...`

Ivan