The types.coroutine decorator for Python 3.6 (and I suspect for Python 3.6.1 as well) simply monkey patches the function it's passed and then returns it. This results in behavior that I found somewhat surprising.

def bar():
   yield 5

foo = types.coroutine(bar)

foo is bar

And, so now both foo and bar are now awaitable. I wasn't really expecting this, and while it's minor, it also doesn't really seem like the right thing to do.