[marcher]

Python 2.6 and 3.0 ship with a new library called multiprocessing which provides mechanisms for process control and intercommunication, which conveniently sidesteps the GIL limitation that prevents multiple core usage.

The library is loosely based around the existing threading API, and allows for seamless transfer of Python objects between processes (unlike other forms of IPC).

[rbanffy]

I know. The library is available to 2.5 as "processing", but starting OS processes when all you wanted were threads is somewhat ugly. I agree it's not possible to do it properly with the GIL in place and attempts to remove it did have less than amazing results on single-thread applications.

That's annoying... Even more annoying when I think it's easier to do in Java ;-)

[scott_s]

If you're running on Linux, then all threads are processes.

[illume]

Not so seemless. Things need to be serialised to transfer them. You need to specially craft code so that it is pickle safe... things don't just work automatically.

Also serialising 100MB or so worth of objects around is really slow. So the process module is not good for many cases of use.