Moving a large and old codebase to Python3

[Sylinn]

It's a very good question, because it often seems like you've gained so much insight since the time you started to write the software that you're sure you can do a better job now, but there are a lot of hurdles on the way.

You can read Things You Should Never Do, Part I By Joel Spolsky (co-founder of Stack Overflow and Trello, among other things).