Why does this hang the system up

[nilamo]

Parallel(n_jobs=-1)(delayed(attempt)(w, pw) for pw in pwds)

What is Parallel? What's delayed?
delayed looks like a decorator, but what does it do?


From that line, my guess is that you're creating a single spare process, which is passed a generator of attempted passwords. Although hopefully that's not the case, since attempt uses global variables and writes to sys.stdout.