the first part of this captures how my company has handled python 2/3. there’s probably 1-2 hundred thousand lines of python 2 that works well and is largely in maintenance mode. if we were going to change it, it would be a piecemeal step by step replacement to a different language, not upgrade to python 3. going from 2 to 3 in sufficiently large code bases is already a language rewrite. the company has moved on from python