Running Python 3.6, I noticed that any type hints that I add to the stub files with a if sys.version_info >= (3, 6): condition, don't have any effect.

After investigating this a little, it seems that semanal.py uses the PYTHON3_VERSION value inside default.py module as sys.version_info and it is currently hardcoded as 3.5.

Using mypy.ini config file with the following content fixes the issue:

[mypy]
    python_version = 3.6

But still the default behaviour is confusing and probably should be changed.