Currently if you have both Python 3 and Python 2 installed, there's no
way to indicate that ".py" files in one area are Python 2 syntax and in
another area are Python 3 syntax. Being able to distinguish between
these would be nice for heterogeneous deployment environments, but is
particularly important for developers who are working on Python 3
conversions.
It would be good to have a PYTHON3PATH which, if present, would be
honored instead of PYTHONPATH. PYTHONPATH could still be honored if
PYTHON3PATH was not present, so this is purely a new feature and
shouldn't have much impact on compatibility.