Python 进程间通信使用 Pipe 却收不到消息？

import osimport timefrom multiprocessing import pipe, processfd1, fd2 = pipe()def fun(name):    time.sleep(3)    # 向管道写入内容    fd1.send({name: os.getpid()})if __name__ == "__main__":    jobs = []    for i in range(5):        p = process(target=fun, args=(i,))        jobs.append(p)        p.start()    for i in range(5):        # 读管道        data = fd2.recv()        print(data)    for i in jobs:        i.join()

def fun(name, fd):    time.sleep(3)    # 向管道写入内容    fd.send({name: os.getpid()})

if __name__ == "__main__":    jobs = []    for i in range(5):        p = Process(target=fun, args=(i, fd1))        jobs.append(p)        p.start()