Python has MPI4PY and Multiprocessing. Not sure why you need threads in the first place.  Also, many matrix operations autoscale to all cores when compiled against Atlas.<p>Finally, you can release the GIL with Cython:
<a href="http:&#x2F;&#x2F;docs.cython.org&#x2F;src&#x2F;userguide&#x2F;parallelism.html" rel="nofollow">http:&#x2F;&#x2F;docs.cython.org&#x2F;src&#x2F;userguide&#x2F;parallelism.html</a>