本文实例讲述了Python实现多线程的两种方式。分享给大家供大家参考，具体如下：
目前python 提供了几种多线程实现方式 thread，threading，multithreading ,其中thread模块比较底层，而threading模块是对thread做了一些包装，可以更加方便的被使用。
2.7版本之前python对线程的支持还不够完善，不能利用多核CPU，但是2.7版本的python中已经考虑改进这点，出现了multithreading 模块。threading模块里面主要是对一些线程的操作对象化，创建Thread的class。一般来说，使用线程有两种模式:
- A 创建线程要执行的函数，把这个函数传递进Thread对象里，让它来执行；
- B 继承Thread类，创建一个新的class，将要执行的代码 写到run函数里面。
本文介绍两种实现方法。
第一种 创建函数并且传入Thread 对象中
t.py 脚本内容
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import threading,timefrom time import sleep, ctimedef now() : return str( time.strftime( '%Y-%m-%d %H:%M:%S' , time.localtime() ) )def test(nloop, nsec): print 'start loop', nloop, 'at:', now() sleep(nsec) print 'loop', nloop, 'done at:', now()def main(): print 'starting at:',now() threadpool=[] for i in xrange(10): th = threading.Thread(target= test,args= (i,2)) threadpool.append(th) for th in threadpool: th.start() for th in threadpool : threading.Thread.join( th ) print 'all Done at:', now()if __name__ == '__main__': main() |
执行结果：
starting at: 2018-08-29 09:34:16
start loop 0 at: 2018-08-29 09:34:16
start loop 1 at: 2018-08-29 09:34:16
start loop 2 at: 2018-08-29 09:34:16start loop 3 at: 2018-08-29 09:34:16start loop 4 start loopat: 52018-08-29 09:34:16
at: 2018-08-29 09:34:16
start loop 6 at: start loop2018-08-29 09:34:16
7 at: 2018-08-29 09:34:16
start loop 8 start loopat: 9 2018-08-29 09:34:16at:
2018-08-29 09:34:16
looploop 1 done at: 2018-08-29 09:34:18
0 done at: 2018-08-29 09:34:18
loop 3 done at: 2018-08-29 09:34:18
looploop 5 done at: 2018-08-29 09:34:18
2 done at: 2018-08-29 09:34:18
loop 4 done at: 2018-08-29 09:34:18
looploop 7 done at: 2018-08-29 09:34:18
6 done at: 2018-08-29 09:34:18
looploop 98 done at:done at: 2018-08-29 09:34:182018-08-29 09:34:18all Done at: 2018-08-29 09:34:18
第二种 创建继承自Thread的类
thclass.py 脚本内容：
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import threading , timefrom time import sleep, ctimedef now() : return str(time.strftime('%Y-%m-%d %H:%M:%S' , time.localtime()))class myThread (threading.Thread) : """docstring for myThread""" def __init__(self, nloop, nsec) : super(myThread, self).__init__() self.nloop = nloop self.nsec = nsec def run(self): print 'start loop', self.nloop, 'at:', ctime() sleep(self.nsec) print 'loop', self.nloop, 'done at:', ctime()def main(): thpool = [] print 'starting at:', now() for i in xrange(10): thpool.append(myThread(i, 2)) for th in thpool: th.start() for th in thpool: th.join() print 'all Done at:', now()if __name__ == '__main__': main() |
执行结果：
starting at: 2018-08-29 09:36:02
start loop 0 at: Wed Aug 29 09:36:02 2018
start loop 1 at: Wed Aug 29 09:36:02 2018
start loop 2 at: Wed Aug 29 09:36:02 2018
start loop 3 at: Wed Aug 29 09:36:02 2018
start loop 4 at: Wed Aug 29 09:36:02 2018
start loop 5 at: Wed Aug 29 09:36:02 2018
start loop 6 at: Wed Aug 29 09:36:02 2018
start loop 7 at: Wed Aug 29 09:36:02 2018
start loop 8 at: Wed Aug 29 09:36:02 2018
start loop 9 at: Wed Aug 29 09:36:02 2018
loop 0 done at: Wed Aug 29 09:36:04 2018
loop 1 done at: Wed Aug 29 09:36:04 2018
looploop 23 done at:done at: Wed Aug 29 09:36:04 2018Wed Aug 29 09:36:04 2018loop 4 done at: Wed Aug 29 09:36:04 2018
loop 5 done at: Wed Aug 29 09:36:04 2018
loop 6 done at: Wed Aug 29 09:36:04 2018
looploop loop 8 9 7 done at: done at: done at: Wed Aug 29 09:36:04 2018 Wed Aug 29 09:36:04 2018
Wed Aug 29 09:36:04 2018all Done at: 2018-08-29 09:36:04
希望本文所述对大家Python程序设计有所帮助。
原文链接：https://blog.csdn.net/xiaofei0859/article/details/51316256
