With 3.1.0, support for Python 2 is being removed (#2215).

With #2678. the minimum version will go up to 3.7 due to the use of f-strings.
However I can't guarantee off the top of my head with 100% assurance that 3.1.0 will work on Python 3.7.

I'd like to add a CI test, probably in conjunction with #2154, that builds a Python 3.7 environment and does some degree of testing of Python scripts. This would ensure that the documented lower bound of support is in fact accurate.