This pattern seems to work:
import sys
if sys.version_info[0] < 3:
raise RuntimeError("Must use at least python version 3")
# The 'typing' module, useful for type hints, was introduced in python 3.5
if sys.version_info[1] >= 5:
from typing import Optional
optional_float = Optional[fl
I think it's great that for built-in types such as int and str, backward
compatibility of type hinting annotations is baked into python 3.0 to 3.4. In
fact, I *thought* python 3.0 to 3.4 would *ignore* annotations, but it
doesn't...
I'm struggling to create something backward compatible that re
