Python线程概念与实例

Python线程概念与实例;Python线程概念与实例;Python线程概念与实例;Python线程概念与实例;Python线程概念与实例;Python线程概念与实例;Python线程概念与实例;Python线程概念与实例;

在单线程中

# -*- coding=utf8 -*-
import threading
from time import ctime, sleep
#单线程实例
def frist(frist_name, length):
    for i in range(4):
        print('I was listening to %s %s'% (frist_name, ctime()))
        sleep(length)
def second(second_name, length):
    for i in range(2):
        print('I was at the movie %s %s'% (second_name, ctime()))
        sleep(length)
if __name__ == '__main__':
    frist('第一线程', 2)
    second('第二线程', 4)
    print('all over %s'% ctime())
    &lt;/pre&gt;

# -*- coding=utf8 -*-

import threading

from time import ctime, sleep

#单线程实例

def frist(frist_name, length):

for i in range(4):

print('I was listening to %s %s'% (frist_name, ctime()))

sleep(length)

def second(second_name, length):

for i in range(2):

print('I was at the movie %s %s'% (second_name, ctime()))

sleep(length)

if __name__ == '__main__':

frist('第一线程', 2)

second('第二线程', 4)

print('all over %s'% ctime())

</pre>

结果

I was listening to 第一线程 Tue Jan 17 23:13:07 2017
I was listening to 第一线程 Tue Jan 17 23:13:09 2017
I was listening to 第一线程 Tue Jan 17 23:13:11 2017
I was listening to 第一线程 Tue Jan 17 23:13:13 2017
I was at the movie 第二线程 Tue Jan 17 23:13:15 2017
I was at the movie 第二线程 Tue Jan 17 23:13:19 2017
all over Tue Jan 17 23:13:23 2017

I was listening to 第一线程 Tue Jan 17 23:13:07 2017

I was listening to 第一线程 Tue Jan 17 23:13:09 2017

I was listening to 第一线程 Tue Jan 17 23:13:11 2017

I was listening to 第一线程 Tue Jan 17 23:13:13 2017

I was at the movie 第二线程 Tue Jan 17 23:13:15 2017

I was at the movie 第二线程 Tue Jan 17 23:13:19 2017

all over Tue Jan 17 23:13:23 2017

多线程中

在多线程中，线程的调用时随机的，所以每次的结果并不一样

# -*- coding=utf8 -*-
import threading
from time import ctime, sleep
#多线程
def frist(frist_name, length):
    for i in range(4):
        print('I was listening to %s %s'% (frist_name, ctime()))
        sleep(length)
def second(second_name, length):
    for i in range(2):
        print('I was at the second %s %s'% (second_name, ctime()))
        sleep(length)
th1 = threading.Thread(target=frist, args=('第一线程', 1))
th2 = threading.Thread(target=second, args=('第二线程', 2))
threads = [th1,th2]

if __name__ == '__main__':
    for t in threads:
        t.setDaemon(True)
        t.start()
    t.join()
print('all over %s' % ctime())&lt;/pre&gt;

# -*- coding=utf8 -*-

import threading

from time import ctime, sleep

#多线程

def frist(frist_name, length):

for i in range(4):

print('I was listening to %s %s'% (frist_name, ctime()))

sleep(length)

def second(second_name, length):

for i in range(2):

print('I was at the second %s %s'% (second_name, ctime()))

sleep(length)

th1 = threading.Thread(target=frist, args=('第一线程', 1))

th2 = threading.Thread(target=second, args=('第二线程', 2))

threads = [th1,th2]

if __name__ == '__main__':

for t in threads:

t.setDaemon(True)

t.start()

t.join()

print('all over %s' % ctime())</pre>

####结果

I was listening to 第一线程 Tue Jan 17 23:25:22 2017
I was at the second 第二线程 Tue Jan 17 23:25:22 2017
I was listening to 第一线程 Tue Jan 17 23:25:23 2017
I was listening to 第一线程 Tue Jan 17 23:25:24 2017
I was at the second 第二线程 Tue Jan 17 23:25:24 2017
I was listening to 第一线程 Tue Jan 17 23:25:25 2017
all over Tue Jan 17 23:25:26 2017

I was listening to 第一线程 Tue Jan 17 23:25:22 2017

I was at the second 第二线程 Tue Jan 17 23:25:22 2017

I was listening to 第一线程 Tue Jan 17 23:25:23 2017

I was listening to 第一线程 Tue Jan 17 23:25:24 2017

I was at the second 第二线程 Tue Jan 17 23:25:24 2017

I was listening to 第一线程 Tue Jan 17 23:25:25 2017

all over Tue Jan 17 23:25:26 2017

threading是Python标准库中的模块，有些朋友查到会有thread这个模块，但是在python3里面只剩下threading这个模块了，因为threading模块用起来更简单也更安全一些

time模块中有ctime()，sleep()等函数，ctime()返回当前时间，用一个str表示，sleep(n)表示挂起n秒
import threading 导入threading模块
th1 = threading.Thread(target=music, args=('第一线程',1)) 创建一个线程th1，threading.Thread()是一个类，类的构造函数原型如下： class threading.Thread(group=None,target=None, name=None, args=(), kwargs={}, *, daemon=None) 这里用到了target，表示要调用的函数名，args表示调用函数的参数

threads = [th1, th2]
将两个线程放入一个列表中
for t in threads:
    t.setDaemon(True)
    t.start()
t.join()
最后使用一个for循环，依次将列表中的线程开启
t.setDaemon(True)

threads = [th1, th2]

将两个线程放入一个列表中

for t in threads:

t.setDaemon(True)

t.start()

t.join()

最后使用一个for循环，依次将列表中的线程开启

t.setDaemon(True)

将线程声明为守护线程，必须在start() 方法调用之前设置，如果不设置为守护线程程序会被无限挂起。子线程启动后，父线程也继续执行下去，当父线程执行完最后一条语句print "all over %s" %ctime()后，没有等待子线程，直接就退出了，同时子线程也一同结束。
t.start()
开始线程活动。
t.join()

join()方法，用于等待线程终止。join（）的作用是，在子线程完成运行之前，这个子线程的父线程将一直等待。

注意: join()方法的位置是在for循环外的，也就是说必须等待for循环里的两个进程都结束后，才去执行主进程。如果没有join()函数，那么父线程执行完之后就会立即结束，不会等待子线程执行完