Python the programming language and versions
Over the many decades Python has become a very stable language. From version to version more things are alike than different. In the last fire or more years people new to the industry have shown their cards by claiming it can't be done.
Not that hard
As I continue to hear sob stories about how hard everything is I keep reaching back to https://www.tomaz.me/2011/12/03/lessons-learned-while-porting-libcloud-to-python-3.html as you can see from the page the date and content show that it is not hard to support various versions if that is a goal.
Almost exactly three years ago in 2014 I did a fast conversion of Ansible to work with Python 3 in PR 8322 which ended up in a land of personal preferences and overly complex solutions to simple problems. I have worked on converting other projects like PyPXE and Saltstack. In each case I hit walls where confusion is apparent and in every case I am supplying working tested code to prove it works.
Write better software, think about the future and the past. Work on problems like anything is possible because it is. Develop good clean interfaces and standard APIs in such a way that the software could be written in any version of any language and operate the same. Think before you code.