本文实例讲述了python开发之thread线程基础。分享给大家供大家参考,具体如下:
说到线程,我们要知道啥是串行,啥是并行程序
举个例子:
串行程序,就是一个一个的执行程序
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#python threading import time ''' 每一秒中,输出:this is a demo! ''' def serial(): '''串行输出''' time.sleep( 1 ) print ( 'this is a demo!' ) def main(): for i in range ( 5 ): serial() if __name__ = = '__main__' : main() |
运行结果如下:
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>>> this is a demo! this is a demo! this is a demo! this is a demo! this is a demo! >>> |
并行程序,就是很多个程序在同一时间(宏观)一起执行
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#python threading import threading import time ''' 并行执行,输出:Good!Good!Good!Good!Good! ''' def parallel(): '''并行输出''' time.sleep( 1 ) print ( 'Good!' ) def main(): for i in range ( 5 ): t = threading.Thread(target = parallel) t.start() if __name__ = = '__main__' : main() |
当然我们通过执行程序,可以知道,并行程序要比串行程序执行的要快....
我们也可以获取到当前的线程及个数:
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#python threading import threading import time ''' 并行执行,输出: [<Thread(Thread-2, started 3480)>, <Thread(Thread-1, started 660)>, <Thread(SockThread, started daemon 2920)>, <Thread(Thread-3, started 916)>, <Thread(Thread-4, started 3476)>, <_MainThread(MainThread, started 3964)>, <Thread(Thread-5, started 2060)>] 存在的线程数 : 7 Good!Good!Good!Good!Good! ''' def parallel(): '''并行输出''' time.sleep( 1 ) print ( 'Good!' ) def main(): for i in range ( 5 ): t = threading.Thread(target = parallel) t.start() if __name__ = = '__main__' : main() print (threading. enumerate ()) print ( '存在的线程数 : %d' % threading.active_count()) |
运行结果如下:
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>>> [<Thread(SockThread, started daemon 15424 )>, <Thread(Thread - 3 , started 15840 )>, <Thread(Thread - 1 , started 10884 )>, <Thread(Thread - 2 , started 14512 )>, <Thread(Thread - 4 , started 13204 )>, <_MainThread(MainThread, started 12924 )>, <Thread(Thread - 5 , started 15476 )>] 存在的线程数 : 7 >>> Good!Good!Good!Good!Good! |
希望本文所述对大家Python程序设计有所帮助。