Not quite.
The GIL locks the access of Python objects as well as the interpretation of the byte codes. So to do any real work with Python in C you still have to obtain the lock. It's basically cooperative multi-tasking.
Additionally, if you create a thread in C, you have to set up a bunch of Python thread bookkeeping structures that will be used by the interpreter as well.
Regards,
-scott anderson
"Welcome to Rivendell, Mr. Anderson..."