进程池

import timefrom concurrent.futures import ProcessPoolExecutordef task(arg):    time.sleep(2)    print(arg)    if __name__ == '__main__':    pool = ProcessPoolExecutor(5)    for i in range(20):        pool.submit(task, i)

线程池

import timefrom concurrent.futures import ThreadPoolExecutordef task(arg):    time.sleep(2)    print(arg)if __name__ == '__main__':    pool = ThreadPoolExecutor(5)    for i in range(20):        pool.submit(task, i)