The syntax is definitely harder to grasp but if the mechanism is there, I guess the parent poster's concern can be solved like that.
Although I understant that it might have been just a simplified example. Usually the "Real World" can get very complex.
> The syntax is definitely harder to grasp
Yes it is. I believe the reason is that this is all valid python while typescript is not valid javascript. Also, python's type annotations are available at runtime (eg. for introspection) while typescript types aren't.
That said, typescript static type system is clearly both more ergonomic and more powerful than Python's.
You can specify a protocol like this:
(Edit: formatting)