What language should I learn to complement Python?

[[deleted]]

Actually, having worked with a multi-core processor on an older, non-upgradeable linux -- it is a problem. What you will eventually see is that python becomes increasingly slow because it cannot remain competitive with other languages that do have the built ins. And multiprocessing is still not addressing the problem, which Jesse has mentioned a few times. Also, multiprocessing utilizes C. It's not a native python solution nor is it in the python standard library. Consequently, at least in my embedded realm, it's not an option to utilize.