Python-Future VS modernize

Python 2.7 has been EOL for over a year. You should avoid needing to use it. If you do please use something like python-future that should help you write code that is backwards / forwards compatible.

Since you think you may be updating this code, I would strongly suggest you check out the six or future packages which help to write code that runs under both python 2 and 3. IME future does a better job of making python2 code look like python3, making the eventual cutover easier, while six makes compromises on both ends and code doesn’t looks strictly like 2 or 3. They both have really good guides for transitioning code as well, even if you don’t import them. Future’s guide was constantly open when I did this work, more so than even the core documentation.

recommends tools: https://python-future.org/automatic_conversion.html, https://github.com/PyCQA/modernize