There's some discussion of this in PEP-484: https://www.python.org/dev/peps/pep-0484/#other-backwards-compatible-conventions https://www.python.org/dev/peps/pep

There's some discussion of this in PEP-484: https://www.python.org/dev/peps/pep-0484/#other-backwards-compatible-conventions https://www.python.org/dev/peps/pep-0484/#other-backwards-co....