On Oct 9, 2019, at 20:56, Chris Angelico <rosuav@gmail.com> wrote:
What you may want to consider is backporting the exact argparse.py from Python 3.7. It's a fairly straight-forward module and will probably work fine on 3.6. That way, once you upgrade to 3.7, it'll keep working the exact same way.
The argparse module on PyPI (which works on 2.3+/3.1+) says it “tries to stay compatible with the module in the standard library, but also supports older Python versions.” So it may already include this feature. And if not, it may be worth submitting a patch to update it to the 3.7 version. That may be trivial, or it may require some complicated rewriting to work with 2.x (in which case it might even be worth creating a separate backport module that requires, say, 3.4+ but is easier to keep in sync with new features).