# Stripped down version of a more flexible example
from threading import Thread, Lock

def __main__():

    let threadcount = 10
    let i = 0
    let lock = Lock()

    class Incrementer(Thread):
        def run():
            for c in range(1000):
                with lock:
                    i += 1

    let threads = [Incrementer() for j in range(threadcount)]
    for thread in threads: thread.start()
    for thread in threads: thread.join()

    print(i)

    return 0

if __name__ == '__main__':
    return __main__()