【python】多任务（2. 进程）

进程间通信 Queue

import  multiprocessing


def download_from_web(q):
    # 模拟从网上下载数据
    data = [11, 22, 33, 44]
    for i in data:
        q.put(i)
    print("---数据下载已写入到队列---")


def analysis_data(q):
    waitting_analysis_data = list()
    while not q.empty():
        waitting_analysis_data.append(q.get())
    print(str(waitting_analysis_data) + " <<< 数据拼接完毕")


def main():

    # 1. 创建一个队列
    q = multiprocessing.Queue(4)
    # 2. 创建多个进程,将队列的引用当作实参进行传递到里面
    p1 = multiprocessing.Process(target=download_from_web, args=(q,))
    p2 = multiprocessing.Process(target=analysis_data, args=(q,))

    p1.start()
    p2.start()

if __name__ == '__main__':
    main()

进程池

from multiprocessing import Pool
import os, time, random

def worker(msg):
    t_start = time.time()

    print("%s 开始执行,进程号为%d" % (msg, os.getpid()))

    time.sleep(random.random() * 2)
    t_stop = time.time()

    print(msg, "执行完毕, 耗时%.2f" % (t_stop - t_start))


def main():
    po = Pool(3)

    for i in range(0,10):
        po.apply_async(worker, (i,))

    print("---start---")
    po.close()
    po.join()
    print("---sop---")

if __name__ == '__main__':
    main()