Python与多线程

逃离我推掉我的手 2023-06-29 02:30 38阅读 0赞

感谢这位博主帮我打开了多线程的门[https://blog.csdn.net/m0\_38011218/article/details/81938261][https_blog.csdn.net_m0_38011218_article_details_81938261]

首先我之前学的java多线程，在java.lang包中有thread类。我们只要集成这个类然后start()。很简单有四种方式

详细见[https://www.cnblogs.com/shoshana-kong/p/9071602.html][https_www.cnblogs.com_shoshana-kong_p_9071602.html]

python具有异曲同工之妙

函数方式；就是简单调用库中的方法

import threading
    import time
    
    
    def sing(num):
        for i in range(num):
            print("sing%d" % i)
            time.sleep(1)
    
    
    def dance(num):
        for i in range(num):
            print("dancd%d" % i)
            time.sleep(1.5)
    
    
    if __name__ == '__main__':
        t_sing = threading.Thread(target=sing, args=(5, ))
        t_dance = threading.Thread(target=dance, args=(5, ))
        t_sing.start()
        t_dance.start()

time.sleep()是为了让运行的顺序明显一点

第二种继承方式：

import threading
    import time
    
    class Mythread(threading.Thread):
        def run(self):
            for i in range(3):
                time.sleep(1)
                msg = 'i\'m' + self.name + '@' +str(i)
                print(msg)
    
    def test():
        for i in range(5):
            t=Mythread()
            t.start()
    
    if __name__ == '__main__':
        test()

join方法可以阻塞主进程（注意只能阻塞主进程，其他子进程是不能阻塞的），直到 子线程执行完，再解阻塞。

无join前

import threading
    import time
    
    class Mythread(threading.Thread):
        def run(self):
            for i in range(3):
                time.sleep(1)
                msg = 'i\'m' + self.name + '@' +str(i)
                print(msg)
    
    def test():
        for i in range(2):
            t=Mythread()
            t.start()
    
    if __name__ == '__main__':
        test()
        print("hello")

![2020011010362080.png][]

join之后：

import threading
    import time
    
    class Mythread(threading.Thread):
        def run(self):
            for i in range(3):
                time.sleep(1)
                msg = 'i\'m' + self.name + '@' +str(i)
                print(msg)
    
    def test():
        for i in range(2):
            t=Mythread()
            t.start()
            t.join()
    
    if __name__ == '__main__':
        test()
        print("hello")

![20200110103751675.png][]先阻塞 了主进程，所以hello是最后输出的

最后让我想起了仿佛在昨日（其实一年前）考完的操作系统，时间片轮转问题，互斥锁问题，wow果然操作系统是门玄学，现在忘得差不多了

[https_blog.csdn.net_m0_38011218_article_details_81938261]: https://blog.csdn.net/m0_38011218/article/details/81938261
[https_www.cnblogs.com_shoshana-kong_p_9071602.html]: https://www.cnblogs.com/shoshana-kong/p/9071602.html
[2020011010362080.png]: https://img-blog.csdnimg.cn/2020011010362080.png
[20200110103751675.png]: https://img-blog.csdnimg.cn/20200110103751675.png