[hot_gril]

Subprocessing is the only way to do full parallelism in Python. The title includes parallelism, and the article says how threading can achieve it specifically if your CPU-bound portion is inside C modules (which release the GIL), but it's relevant to mention how you do parallelism in the general case.

[mixmastamyk]

Problems communicating with a crashy subprocess are not what I came to the thread for. Certainly not had issues like that myself.

If you wrote the subprocess, add quality and some communication hooks. If you didn't, get a better one or kill -9 it regularly.