How to avoid this awful Mypy syntax?

Question

I want to set the type of f as typing.IO[typing.Any]. The code below gets that done, but putting typing code in a comment rubs me wrong.

with open(cache_file) as f:  # type: typing.IO[typing.Any]
    cache_dict = json.load(f)

Is there any other syntax available for this situation where a colon immediately follows the variable I want to set the type for? I was hoping for something like this:

   with open(cache_file) as f: typing.IO[typing.Any]:
        cache_dict = json.load(f)