Python多线程基础学习

python多线程用法：
1.函数式：调用thread模块的start_new_thread()方法来创建线程，
例如：

thread.start_new_thread(function,args)

–function是你要在线程里要执行的函数名称，在此相当于一个函数指针.

–args是函数的参数列表，在python里用元组表示，如（’args1’,args2……)，注意这里参数必须存在，就算是个无参函数，也要传递一个空元组（）

实例：

#!/usr/bin/python
#coding＝UTF-8

import thread
import time

# 为线程定义一个函数
def print_time( threadName, delay):
   count = 0
   while count < 5:
      time.sleep(delay)
      count += 1
      print "%s: %s" % ( threadName, time.ctime(time.time()) )

# 创建两个线程
try:
   thread.start_new_thread( print_time, ("Thread-1", 2, ) )
   thread.start_new_thread( print_time, ("Thread-2", 4, ) )
except:
   print "Error: unable to start thread"

while 1:
   pass

输出为：

Thread-1: Sun Jul 17 16:11:04 2016
Thread-2: Sun Jul 17 16:11:06 2016
Thread-1: Sun Jul 17 16:11:06 2016
Thread-1: Sun Jul 17 16:11:08 2016
Thread-2: Sun Jul 17 16:11:10 2016
Thread-1: Sun Jul 17 16:11:10 2016
Thread-1: Sun Jul 17 16:11:12 2016
Thread-2: Sun Jul 17 16:11:14 2016
Thread-2: Sun Jul 17 16:11:18 2016
Thread-2: Sun Jul 17 16:11:22 2016

2.继承类threading.Thread，自定义线程类，重写init()和run()方法，
实例：

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import threading
import time

exitFlag = 0

class myThread (threading.Thread):   #继承父类threading.Thread
    def __init__(self, threadID, name, counter):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.name = name
        self.counter = counter
    def run(self):                   #把要执行的代码写到run函数里面 线程在创建后会直接运行run函数 
        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

# 创建新线程
thread1 = myThread(1, "Thread-1", 1)
thread2 = myThread(2, "Thread-2", 2)

# 开启线程
thread1.start()
thread2.start()

print "Exiting Main Thread"

输出：

Starting Thread-1
Starting Thread-2
Exiting Main Thread
Thread-1: Thu Mar 21 09:10:03 2013
Thread-1: Thu Mar 21 09:10:04 2013
Thread-2: Thu Mar 21 09:10:04 2013
Thread-1: Thu Mar 21 09:10:05 2013
Thread-1: Thu Mar 21 09:10:06 2013
Thread-2: Thu Mar 21 09:10:06 2013
Thread-1: Thu Mar 21 09:10:07 2013
Exiting Thread-1
Thread-2: Thu Mar 21 09:10:08 2013
Thread-2: Thu Mar 21 09:10:10 2013
Thread-2: Thu Mar 21 09:10:12 2013
Exiting Thread-2