Re: Extinct
"Everything is assigned by reference"
True. But
x=1
y=x
assigns a reference to the constant "1" to y, so this behaves like an assignment in every other language I've ever seen. Whereas if x is (the name of) a compound object you get a reference to the object. If that's not what you want, you have to use copy or deepcopy or whatever.
I have no intellectual difficulty understanding this. But it really is a trap for the unwary.