f-strings. Enum. Dataclasses. asyncio. Type annotations as code. An explicit separation between bytes and strings. I love each of these and use them regularly. It's not that 2.7 is some abomination I can't stomach, but more that 3.[recent] is all of the things I appreciated about 2.7, plus a million little quality of life and performance enhancements that make it just that much more pleasant to use. I could live without each of those things individually, but would not be willing to give them all up.