你不能将普通的 multiprocessing.Lock 对象传递给 Pool 方法，因为它们不能被腌制.有两种方法可以解决这个问题.一种是创建 Manager() 和传递一个 Manager.Lock():

You can't pass normal multiprocessing.Lock objects to Pool methods, because they can't be pickled. There are two ways to get around this. One is to create Manager() and pass a Manager.Lock():

def main():
    iterable = [1, 2, 3, 4, 5]
    pool = multiprocessing.Pool()
    m = multiprocessing.Manager()
    l = m.Lock()
    func = partial(target, l)
    pool.map(func, iterable)
    pool.close()
    pool.join()

不过，这有点重量级；使用 Manager 需要生成另一个进程来托管 Manager 服务器.并且所有对 acquire/release 锁的调用都必须通过 IPC 发送到该服务器.

This is a little bit heavyweight, though; using a Manager requires spawning another process to host the Manager server. And all calls to acquire/release the lock have to be sent to that server via IPC.

另一个选项是在创建池时使用 initializer kwarg 传递常规的 multiprocessing.Lock().这将使您的锁实例在所有子工作者中都是全局的:

The other option is to pass the regular multiprocessing.Lock() at Pool creation time, using the initializer kwarg. This will make your lock instance global in all the child workers:

def target(iterable_item):
    for item in items:
        # Do cool stuff
        if (... some condition here ...):
            lock.acquire()
            # Write to stdout or logfile, etc.
            lock.release()
def init(l):
    global lock
    lock = l

def main():
    iterable = [1, 2, 3, 4, 5]
    l = multiprocessing.Lock()
    pool = multiprocessing.Pool(initializer=init, initargs=(l,))
    pool.map(target, iterable)
    pool.close()
    pool.join()

第二种解决方案的副作用是不再需要partial.

The second solution has the side-effect of no longer requiring partial.