The mistake that a lot of "technique x" aficiandos make seems to often be that the technique has to be 100% complete or it's completely worthless. In this case

The mistake that a lot of "technique x" aficiandos make seems to often be that the technique has to be 100% complete or it's completely worthless. In this case, there's a claim that python isn't actually REPL-based because you cannot change state while in an exception handler. Yes, that's kinda true, but there are debuggers for python that if you really need to can do a lot of that. Other notable examples of this are type system maximalists. E.g. Go: no sum types or generics (until recently). Rust: no HKTs. Python: no runtime checks (I actually sometimes think this :)).