所有子进程并行运行。（为避免这种情况，必须明确等待其完成。）它们甚至可以同时写入日志文件，从而使输出无效。为避免这种情况，您应该让每个进程写入不同的日志文件，并在所有进程完成后收集所有输出。
q = Queue.Queue()result = {} # used to store the resultsfor fileName in fileNames: q.put(fileName)def worker(): while True: fileName = q.get() if fileName is None: # EOF? return subprocess_stuff_using(fileName) wait_for_finishing_subprocess() checksum = collect_md5_result_for(fileName) result[fileName] = checksum # store itthreads = [ threading.Thread(target=worker) for _i in range(20) ]for thread in threads: thread.start() q.put(None) # one EOF marker for each thread之后，结果应存储在中
result。
