多进程multiprocessing通信multiprocessing.Queue

multiprocessing.Queue` 通常只能在主模块（即 `if name == "main":` 块）中创建和使用。这是因为 `multiprocessing` 模块在 Windows 系统上需要通过 `if name == "main":` 块来避免递归导入问题。

from multiprocessing import Queue, Process


def work(queue):
    queue.put("我已发送消息到主进程")


if __name__ == "__main__":
    # 实例化一个消息通道
    queue = Queue()
    # 实例化一个进程
    process = Process(target=work, args=(queue,))
    # 启动子进程
    process.start()
    print("主进程等待消息")
    msg = queue.get()
    print("主进程收到消息:", msg)
    process.join()
    print("主进程结束")

当然 你也可以双向通信

from multiprocessing import Queue, Process


def work(input_queue, output_queue):
    input_queue.put("我已发送消息到主进程")
    msg = output_queue.get()
    print("主进程发送消息已收到", msg)


if __name__ == "__main__":
    # 实例化一个消息通道
    input_queue = Queue()
    output_queue = Queue()
    # 实例化一个进程
    process = Process(target=work, args=(input_queue, output_queue))
    # 启动子进程
    process.start()
    print("主进程等待消息")
    msg = input_queue.get()
    print("主进程收到消息:", msg)
    output_queue.put("这里是主进程发送消息")
    process.join()
    print("主进程结束")

还可持续通信

from multiprocessing import Queue, Process


def work(input_queue, output_queue):
    while 1:
        msg = output_queue.get()
        print("主进程发送消息已收到", msg)
        if msg == 2:
            input_queue.put("关闭")
            break
        else:
            input_queue.put("子进程已收到消息")


if __name__ == "__main__":
    # 实例化一个消息通道
    input_queue = Queue()
    output_queue = Queue()
    # 实例化一个进程
    process = Process(target=work, args=(input_queue, output_queue))
    # 启动子进程
    process.start()
    print("主进程等待消息")
    while 1:
        try:
            msg = input_queue.get(timeout=1)
        except:
            msg = "666"
        if msg != "关闭":
            if msg != "666":
                print("主进程收到消息:", msg)
            input_msg = int(input("输入数值2退出"))
            output_queue.put(input_msg)
        else:
            print("进程结束")
            break
    process.join()
    print("主进程结束")