Python 使用Threading创建多线程

阳光穿透心脏的1/2处 2022-05-16 10:43 219阅读 0赞

# 三种方法创建多线程 #

*  创建 Thread 的实例，传给它一个函数。
 *  创建 Thread 的实例，传给它一个可调用的类实例。
 *  派生 Thread 的子类，并创建子类的实例。

## 1、创建 Thread 的实例，传给它一个函数 ##

上代码

import threading
    from time import sleep,ctime
    
    loops = [4,2]
    
    def loop(nloop,nsec):
        print('start loop',nloop,'at:',ctime())
        sleep(nsec)
        print('loop',nloop,'done at:',ctime())
    
    def main():
        print('starting at:',ctime())
        threads = []
    
        nloops = list(range(len(loops)))
        for i in nloops:
            t = threading.Thread(target=loop,
                args=(i,loops[i]))
            threads.append(t)
    
        for i in nloops: #开始多线程
            threads[i].start()
    
        for i in nloops: #等待所有线程完成
            threads[i].join()
    
        print('all done at:',ctime())
    
    if __name__ == '__main__':
        main()

运行结果为：

starting at: Mon Aug 20 09:46:14 2018
    start loop 0 at: Mon Aug 20 09:46:14 2018
    start loop 1 at: Mon Aug 20 09:46:14 2018
    loop 1 done at: Mon Aug 20 09:46:16 2018
    loop 0 done at: Mon Aug 20 09:46:18 2018
    all done at: Mon Aug 20 09:46:18 2018

## 2、创建 Thread 的实例，传给它一个可调用的类实例 ##

import threading
    from time import sleep,ctime
    
    loops = [4,2]
    
    class ThreadFunc(object):
        def __init__(self,func,args,name=''):
            self.name = name
            self.func = func
            self.args = args
        def __call__(self):
            self.func(*self.args)
    
    def loop(nloop,nsec):
        print('start loop',nloop,'at:',ctime())
        sleep(nsec)
        print('loop',nloop,'done at:',ctime())
    
    def main():
        print('starting at:',ctime())
        threads = []
        nloops = list(range(len(loops)))
    
        for i in nloops:
            t = threading.Thread(
                target=ThreadFunc(loop,(i,loops[i]),
                    loop.__name__))
            threads.append(t)
    
        for i in nloops: #开始多线程
            threads[i].start()
    
        for i in nloops: #等待所有线程完成
            threads[i].join()
    
        print('all done at:',ctime())
    
    if __name__ == '__main__':
        main()

运行结果为：

starting at: Mon Aug 20 09:43:49 2018
    start loop 0 at: Mon Aug 20 09:43:49 2018
    start loop 1 at: Mon Aug 20 09:43:49 2018
    loop 1 done at: Mon Aug 20 09:43:51 2018
    loop 0 done at: Mon Aug 20 09:43:53 2018
    all done at: Mon Aug 20 09:43:53 2018

## 3、派生 Thread 的子类，并创建子类的实例 ##

import threading
    from time import sleep,ctime
    
    loops = (4,2)
    
    class MyThread(threading.Thread):
        def __init__(self, func, args, name=''):
            threading.Thread.__init__(self)
            self.name = name
            self.func = func
            self.args = args
    
        def run(self):
            self.func(*self.args)
    
    def loop(nloop,nsec):
        print('start loop',nloop,'at:',ctime())
        sleep(nsec)
        print('loop',nloop,'done at:',ctime())
    
    def main():
        print('starting at:',ctime())
        threads = []
        nloops = list(range(len(loops)))
    
        for i in nloops:
            t = MyThread(loop,(i,loops[i]),loop.__name__)
            threads.append(t)
    
        for i in nloops: #开始多线程
            threads[i].start()
    
        for i in nloops: #等待所有线程完成
            threads[i].join()
    
        print('all done at:',ctime())
    
    if __name__ == '__main__':
        main()

运行结果为：

starting at: Mon Aug 20 09:52:43 2018
    start loop 0 at: Mon Aug 20 09:52:43 2018
    start loop 1 at: Mon Aug 20 09:52:43 2018
    loop 1 done at: Mon Aug 20 09:52:45 2018
    loop 0 done at: Mon Aug 20 09:52:47 2018
    all done at: Mon Aug 20 09:52:47 2018