Idiosyncrasies of Python

1. If say thread A does a thread join on thread B, thread A will block (and be uninterruptible by signals) until thread B completes. (more info here)
2. The Global Interpreter Lock in CPython. JPython and IronPython have no GIL. To get around GIL, consider using the multiprocessing module, i.e. processes instead of threads.

(More to come!)