一、进程池

import time    from multiprocessing import Pool    import random    import os    def run(i):    start = time.time()    time.sleep(random.uniform(1.0,10.0))    end = time.time()    print("这是第%d个进程%d,耗时%.2f秒" % (i, os.getpid(), end - start))if __name__=="__main__":    print("进程开始")    p=Pool(4)    for i in range(10):        p.apply_async(run,(i,))    p.close()    p.join()    print("父进程结束")