mypy

14de8c6f - Use `__truediv__` for python2 with `__future__` import, refs #11740 (#11787)

Use `__truediv__` for python2 with `__future__` import, refs #11740 (#11787) Now `__future__` imports do not leak in semanal.py. Closes #11740 Refs #11741 Refs #11276 Refs #11700