I draw the line where it crosses into understanding a language other than the runtime language. You don't really need to understand anything more than pure Java to understand 99.99% of popular Java libraries (I already listed the exceptions).
You don't even need to understand JVM bytecode (though that can really help for performance optimisation).
You can't use almost any meaningful library without running into a C extension in Python-land and that is what I have a serious issue with. (same goes for Ruby and JS though I guess)
You don't even need to understand JVM bytecode (though that can really help for performance optimisation).
You can't use almost any meaningful library without running into a C extension in Python-land and that is what I have a serious issue with. (same goes for Ruby and JS though I guess)