import time

from multiprocessing import Process,Event

def f1(e):

    time.sleep(2)

    n = 100

    print("子进程计算结果位:",n)

    e.set()

if __name__ == '__main__':

    e = Event()

    p = Process(target=f1,args=(e,))

    p.start()

    print("主进程等待")

    e.wait()

    print("结果已经写入文件了,可以拿到这值")