If the argument is an expression (formula) it will evaluate it first. I don't do python3, but i imagine the python 2 "print x, y" command corresponds to "python (x,y)" if you want to think of it that ...

Background: I'm a statistician data scientist who works mainly in R, and has done some C and C++ coding (numerical algorithms, not any general-purpose stuff). I'm looking to learn Python, which seems ...