As in many functions in python3, io.open_code should probably accept pathlike objects and not just path strings.

Below is  open_code's docstring:
> Opens the provided file with the intent to import the contents.
> This may perform extra validation beyond open(), but is otherwise interchangeable with calling open(path, 'rb').

The second bit is not entirely true, as open accepts pathlike objects and open_code doesn't.
Fixing this will help solve future bugs and existing bugs like https://bugs.python.org/issue39517

I'd be happy to open a pull request if it is agreed that this should be changed.