Python2 retired, talk about the big Python2 project requires energy to modify for python3 project

There are many projects in the lot are based on python2 implementation, is now facing a problem whether need to python3 python2 project project, or continue to do

But there are also a small tool for large project conversion - turn python2 python3 project https://github.com/99kies/2to3 if there is a better way please comment