python 多进程的启动和停止
Python3.5多进程原理与用法实例分析本文实例讲述了python3.5多进程原理与用法。分享给大家供大家参考,具体如下:
进程类:process
示例及代码:
(1)创建函数作为单进程
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#!/usr/bin/env python # -*- coding:utf-8 -*- # author:zhengzhengliu import multiprocessing import time #创建函数并将其作为单个进程 def worker(interval): n = 5 #进程数 while n> 0 : print ( "the time is :{0}" . format (time.ctime())) #初始化时间 time.sleep(interval) #睡眠时间 n - = 1 if __name__ = = "__main__" : # 创建进程,target:调用对象,args:传参数到对象 p = multiprocessing.process(target = worker,args = ( 2 ,)) p.start() #开启进程 print ( "进程号:" ,p.pid) print ( "进程别名:" ,p.name) print ( "进程存活状态:" ,p.is_alive()) |
运行结果:
进程号: 6784
进程别名: process-1
进程存活状态: true
the time is :wed nov 1 10:59:03 2017
the time is :wed nov 1 10:59:05 2017
the time is :wed nov 1 10:59:07 2017
the time is :wed nov 1 10:59:09 2017
the time is :wed nov 1 10:59:11 2017
(2)创建函数作为多进程
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#!/usr/bin/env python # -*- coding:utf-8 -*- # author:zhengzhengliu import multiprocessing import time #创建函数作为多进程 def work1(interval): print ( "work1..." ) time.sleep(interval) print ( "end work1..." ) def work2(interval): print ( "work2..." ) time.sleep(interval) print ( "end work2..." ) def work3(interval): print ( "work3..." ) time.sleep(interval) print ( "end work3..." ) if __name__ = = "__main__" : p1 = multiprocessing.process(target = work1,args = ( 1 ,)) p2 = multiprocessing.process(target = work2,args = ( 2 ,)) p3 = multiprocessing.process(target = work3,args = ( 3 ,)) p1.start() p2.start() p3.start() print ( "the number of cpu is %d:" % (multiprocessing.cpu_count())) #打印cpu核数 for p in multiprocessing.active_children(): #循环打印子进程的名称和pid print ( "子进程名称:%s,子进程pid:%d" % (p.name,p.pid)) print ( "ending...." ) |
运行结果:
the number of cpu is 4:
子进程名称:process-2,子进程pid:7108
子进程名称:process-1,子进程pid:1896
子进程名称:process-3,子进程pid:7952
ending....
work3...
work1...
work2...
end work1...
end work2...
end work3...
注:先运行主进程的内容,再运行子进程
(3)将进程定义成一个类
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#!/usr/bin/env python # -*- coding:utf-8 -*- # author:zhengzhengliu import multiprocessing import time #将进程定义为一个类 class clockprocess(multiprocessing.process): def __init__( self ,interval): multiprocessing.process.__init__( self ) #重构了process类里面的构造函数 self .interval = interval def run( self ): #固定用run方法,启动进程自动调用run方法 n = 5 while n> 0 : print ( "the time is {0}" . format (time.ctime())) time.sleep( self .interval) n - = 1 if __name__ = = "__main__" : p = clockprocess( 2 ) p.start() |
运行结果:
the time is wed nov 1 11:31:28 2017
the time is wed nov 1 11:31:30 2017
the time is wed nov 1 11:31:32 2017
the time is wed nov 1 11:31:34 2017
the time is wed nov 1 11:31:36 2017
(4)queue(队列)实现多进程数据传输
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#!/usr/bin/env python # -*- coding:utf-8 -*- # author:zhengzhengliu import multiprocessing #queue是多进程安全的队列,可以使用实现多进程之间的数据传递 def writer_proc(q): try : q.put( 1 ,block = false) #put方法插入数据到队列中 except : pass def reader_proc(q): try : print (q.get(block = false)) #get方法从队列中读取并删除一个元素 except : pass if __name__ = = "__main__" : q = multiprocessing.queue() writer = multiprocessing.process(target = writer_proc,args = (q,)) writer.start() reader = multiprocessing.process(target = reader_proc,args = (q,)) reader.start() reader.join() writer.join() |
运行结果:
1
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/loveliuzz/article/details/78411458