如何设置它以便线程通信他们完成任务？

将线程添加到列表中join().

from threading import Thread
tlist = []
for i in range(3):
    t = Thread(target=some_function)
    t.start()
    tlist.append(t)

# wait until threads have finished executing
for t in tlist:
    t.join()

print 'complete!'