[smeg]

Or just write the fast bits in C, call it from Python via ctypes and get the GIL unlocked and parallelism for free.

[Nursie]

If my projects were large enough to make that a more attractive option, sure, that's a great plan.

Usually when I've hit this situation I'm writing something simple but processor intensive, and it's easier for me (12 years commercial parallel/distributed C programming, amateur python enthusiast) to go back to home ground at this point.