Or simpler

<pre><code>
import threading

def to_run(): # should not take arguments.
    ... # code to execute in the thread (can be a loop, ...) 
        # it uses the same variables as in the main thread.

new_thread = threading.Thread() # create a new thread object.
new_thread.run = to_run
new_thread.start() # the new thread is created and then is running.
</code></pre>