# std lib modules. "Batteries included" FTW.
import threading
import time

thread_result = -1

def ThreadWork():
  global thread_result
  thread_result = 1 + 1
  time.sleep(5)  # phew, I'm tiered after all that addition!

my_thread = threading.Thread(target=ThreadWork)
my_thread.start()  # This will call ThreadWork in the background.
                   # In the mean time, you can do other stuff
y = 2 * 5  # Completely independent calculation.
my_thread.join()  # Wait for the thread to finish doing it's thing.
                  # This should take about 5 seconds,
                  # due to time.sleep being called
print "thread_result * y =", thread_result * y