This is to ensure only one thread at a time can modify Python objects, so data doesn’t get corrupted. Python threads aren’t good for running CPU-bound tasks side by side (at least not for now).

If one of those processes were to have four threads, each thread would get 5% of the CPU's time. (Things are obviously more complex than that, but this is a good way to think about it at a high level.

Israeli researchers have developed a new software "platform" to turn easily readable Python instructions into low-level machine code and execute it in RAM without going through the CPU.