Python的多线程与多进程编程示例

使用示例：

多进程：

# -*- coding: utf-8 -*-
"""
Python多进程的简单使用
"""
from multiprocessing import Process
from os import getpid
from random import randint
from time import time, sleep


def download_task(filename):
    print('启动下载进程，进程号[%d].' % getpid())
    print('开始下载%s...' % filename)
    time_to_download = randint(5, 10)
    sleep(time_to_download)
    print('%s下载完成! 耗费了%d秒' % (filename, time_to_download))


def main():
    start = time()
    p1 = Process(target=download_task, args=('Python从入门到住院.pdf', ))
    p1.start()
    p2 = Process(target=download_task, args=('Peking Hot.avi', ))
    p2.start()
    p1.join()  # 等待进程1执行完毕，再执行下一步
    p2.join()  # 等待进程2执行完毕，再执行下一步
    end = time()
    print('总共耗费了%.2f秒.' % (end - start))


if __name__ == '__main__':
    main()

多线程：

# -*- coding: utf-8 -*-
"""
Python的多线程简单使用
"""
from random import randint
from threading import Thread
from time import time, sleep


def download(filename):
    print('开始下载%s...' % filename)
    time_to_download = randint(5, 10)
    sleep(time_to_download)
    print('%s下载完成! 耗费了%d秒' % (filename, time_to_download))


def main():
    start = time()
    t1 = Thread(target=download, args=('Python从入门到住院.pdf',))
    t1.start()
    t2 = Thread(target=download, args=('Peking Hot.avi',))
    t2.start()
    t1.join()  # 等待线程1执行完毕，再执行下一步
    t2.join()  # 等待线程2执行完毕，再执行下一步
    end = time()
    print('总共耗费了%.3f秒' % (end - start))


if __name__ == '__main__':
    main()

或者通过继承Thread类的方式来创建自定义的线程类，然后再创建线程对象并启动线程：

from random import randint
from threading import Thread
from time import time, sleep


class DownloadTask(Thread):

    def __init__(self, filename):
        super().__init__()
        self._filename = filename

    def run(self):
        print('开始下载%s...' % self._filename)
        time_to_download = randint(5, 10)
        sleep(time_to_download)
        print('%s下载完成! 耗费了%d秒' % (self._filename, time_to_download))


def main():
    start = time()
    t1 = DownloadTask('Python从入门到住院.pdf')
    t1.start()
    t2 = DownloadTask('Peking Hot.avi')
    t2.start()
    t1.join()  # 等待线程1执行完毕，再执行下一步
    t2.join()  # 等待线程2执行完毕，再执行下一步
    end = time()
    print('总共耗费了%.2f秒.' % (end - start))


if __name__ == '__main__':
    main()

注意：
在平时的使用中，就不需要调用join()来等待进程和线程的执行完毕了，不然会导致主进程和主线程的阻塞。

本文地址：https://blog.csdn.net/guanmaoning/article/details/107372013