在Python中通过threading模块定义和调用线程的方法
发布时间:2020-12-16 20:30:09 所属栏目:Python 来源:网络整理
导读:定义线程 最简单的方法:使用target指定线程要执行的目标函数,再使用start()启动。 语法: class threading.Thread(group=None,target=None,name=None,args=(),kwargs={}) group恒为None,保留未来使用。target为要执行的函数名。name为线程名,默认为Threa
定义线程 最简单的方法:使用target指定线程要执行的目标函数,再使用start()启动。 语法: class threading.Thread(group=None,target=None,name=None,args=(),kwargs={}) group恒为None,保留未来使用。target为要执行的函数名。name为线程名,默认为Thread-N,通常使用默认即可。但服务器端程序线程功能不同时,建议命名。 #!/usr/bin/env python3 # coding=utf-8 import threading def function(i): print ("function called by thread {0}".format(i)) threads = [] for i in range(5): t = threading.Thread(target=function,args=(i,)) threads.append(t) t.start() t.join() 执行结果: $ ./threading_define.py function called by thread 0 function called by thread 1 function called by thread 2 function called by thread 3 function called by thread 4 确定当前线程 #!/usr/bin/env python3 # coding=utf-8 import threading import time def first_function(): print (threading.currentThread().getName()+ str(' is Starting n')) time.sleep(3) print (threading.currentThread().getName()+ str( ' is Exiting n')) def second_function(): print (threading.currentThread().getName()+ str(' is Starting n')) time.sleep(2) print (threading.currentThread().getName()+ str( ' is Exiting n')) def third_function(): print (threading.currentThread().getName()+ str(' is Starting n')) time.sleep(1) print (threading.currentThread().getName()+ str( ' is Exiting n')) if __name__ == "__main__": t1 = threading.Thread(name='first_function',target=first_function) t2 = threading.Thread(name='second_function',target=second_function) t3 = threading.Thread(name='third_function',target=third_function) t1.start() t2.start() t3.start() 执行结果: $ ./threading_name.py first_function is Starting second_function is Starting third_function is Starting third_function is Exiting second_function is Exiting first_function is Exiting 配合logging模块一起使用: #!/usr/bin/env python3 # coding=utf-8 import logging import threading import time logging.basicConfig( level=logging.DEBUG,format='[%(levelname)s] (%(threadName)-10s) %(message)s',) def worker(): logging.debug('Starting') time.sleep(2) logging.debug('Exiting') def my_service(): logging.debug('Starting') time.sleep(3) logging.debug('Exiting') t = threading.Thread(name='my_service',target=my_service) w = threading.Thread(name='worker',target=worker) w2 = threading.Thread(target=worker) # use default name w.start() w2.start() t.start() 执行结果: $ ./threading_names_log.py[DEBUG] (worker ) Starting [DEBUG] (Thread-1 ) Starting [DEBUG] (my_service) Starting [DEBUG] (worker ) Exiting [DEBUG] (Thread-1 ) Exiting [DEBUG] (my_service) Exiting
前面我们的线程都是结构化编程的形式来创建。通过集成threading.Thread类也可以创建线程。Thread类首先完成一些基本上初始化,然后调用它的run()。run()方法会会调用传递给构造函数的目标函数。 #!/usr/bin/env python3 # coding=utf-8 import logging import threading import time exitFlag = 0 class myThread (threading.Thread): def __init__(self,threadID,name,counter): threading.Thread.__init__(self) self.threadID = threadID self.name = name self.counter = counter def run(self): print ("Starting " + self.name) print_time(self.name,self.counter,5) print ("Exiting " + self.name) def print_time(threadName,delay,counter): while counter: if exitFlag: thread.exit() time.sleep(delay) print ("%s: %s" %(threadName,time.ctime(time.time()))) counter -= 1 # Create new threads thread1 = myThread(1,"Thread-1",1) thread2 = myThread(2,"Thread-2",2) # Start new Threads thread1.start() thread2.start() print ("Exiting Main Thread") 执行结果: $ ./threading_subclass.py Starting Thread-1 Starting Thread-2 Exiting Main Thread Thread-1: Tue Sep 15 11:03:21 2015 Thread-2: Tue Sep 15 11:03:22 2015 Thread-1: Tue Sep 15 11:03:22 2015 Thread-1: Tue Sep 15 11:03:23 2015 Thread-2: Tue Sep 15 11:03:24 2015 Thread-1: Tue Sep 15 11:03:24 2015 Thread-1: Tue Sep 15 11:03:25 2015 Exiting Thread-1 Thread-2: Tue Sep 15 11:03:26 2015 Thread-2: Tue Sep 15 11:03:28 2015 Thread-2: Tue Sep 15 11:03:30 2015 Exiting Thread-2 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |