This is the direction multiple languages are moving in. Go and Rust both have something like this. (In Rust they're called "editions"). I think its inevitable that compilers get larger over time. I hope most of the time they aren't too onerous to maintain - there aren't that many spec breaking changes between versions. But if need be, I could also imagine the compiler eventually deprecating old versions if it becomes too much of an issue.
Arguably C & C++ compilers do the same thing via -std=c99 and similar flags at compile time.
Anyway, nothing about this is special or different with python. I bet the transition to python 3 would have been much smoother if scripts could have opted in (or opted out) of the new syntax without breaking compatibility.
Arguably C & C++ compilers do the same thing via -std=c99 and similar flags at compile time.
Anyway, nothing about this is special or different with python. I bet the transition to python 3 would have been much smoother if scripts could have opted in (or opted out) of the new syntax without breaking compatibility.