type hinting backward compatibility with python 3.0 to 3.4
Chris Angelico wrote:
> They're function metadata. What would the principle of least surprise
> say about this?
> def func(arg: print("Foo") = print("Quux")):
Most languages that have static type declarations wouldn't
let you write something like that in the first place, so the
fact that Python does is surprising to begin with.