At the end of foo(), create a Timer which calls foo() itself after 10 seconds.
Because, Timer create a new thread to call foo().
You can do other stuff without being blocked.
import time, threading
def foo():
print(time.ctime())
threading.Timer(10, foo).start()
foo()
#output:
#Thu Dec 22 14:46:08 2011
#Thu Dec 22 14:46:18 2011
#Thu Dec 22 14:46:28 2011
#Thu Dec 22 14:46:38 2011