This has been a long time in the making.
We should pause for a minute and think about what just happened. It’s not often that a language choses to break backwards compatibility for the sake of the language. I, for one, give the entire Python dev team and community a great deal of thanks for not only allowing it to happen, but for having the vision that if it didn’t then we’d be far worse off. Look at Java’s generics and how they were bolted on to the language. If Java had chosen to break some compatibility, where would the language be today? Yeah, maybe folks wouldn’t adopt it up front, but that’s okay. It always takes time to move across those boundaries, and it will happen.
Congratulations to the team and the community!
Grab it now! Port your code!