python自动化--语言基础线程、生产者消费者示例

进程与线程的区别：
进程不共享空间，线程共享地址空间

线程共享空间优缺点：
优点：多线程给用户的体验好些，打开时占用的内存比进程少
缺点：共享地址空间会相互干扰，甚至有影响

import threading
import time

class Mythreading(threading.Thread):
    def __init__(self,threadID,name,counter):
        threading.Thread.__init__(self)    #固定格式
        self.threadID = threadID
        self.name = name
        self.counter = counter
        print("初始化完成")
    def run(self):                         #由cpu来处理决定线程间的执行顺序
        print("开始"+self.name)
        print_time(self.name,self.counter,5)
        print("结束"+self.name)

def print_time(threasName,counter,delay):
    while counter:
        time.sleep(delay)
        print("%s:%s"%(threasName,time.ctime(time.time())))
        counter -= 1

#创建线程
thread1 = Mythreading(1,"thread1",1)
thread2 = Mythreading(2,"thread2",2)

#开启线程
thread1.start()
thread2.start()

import threading
import time

class Mythreading(threading.Thread):
    def __init__(self,threadID,name,counter):
        threading.Thread.__init__(self)    #固定格式
        self.threadID = threadID
        self.name = name
        self.counter = counter
        print("初始化完成")
    def run(self):                         #由cpu来处理决定线程间的执行顺序
        threadLock.acquire()               #获得锁，成功获得锁定后返回True，可选的参数timeout不填时将一直阻塞直到获得锁定
        print_time(self.name,self.counter,3)
        threadLock.release()               #释放锁，开始下一个线程

def print_time(threasName,counter,delay):
    while counter:
        time.sleep(delay)
        print("%s:%s"%(threasName,time.ctime(time.time())))
        counter -= 1

threadLock = threading.Lock()
threads = []

#创建线程
thread1 = Mythreading(1,"thread1",1)
thread2 = Mythreading(2,"thread2",2)

#开启线程
thread1.start()
thread2.start()

# thread1.join()
# thread2.join()
threads.append(thread1)
threads.append(thread2)
for t in threads:
    t.join()       #后边的代码必须等待，等线程运行完成才会往后运行代码

print("我的的花儿也谢了")

为什么下图左为串行，下图右为并行运行呢？

图左love启动后分别执行start和join，启动了join后边代码就需要等待前边代码运行完成。总共18s

图右同时启动love和hate，运行所需要执行的时间然后停止。总共10s

 超级播放器示例，如下：

import threading
from time import sleep, ctime
def music(func):
    for i in range(2):
        print ("I was listening to %s! %s" %(func,ctime()))
        sleep(4)
def move(func):
    for i in range(2):
        print ("I was at the %s! %s" %(func,ctime()))
        sleep(5)

def player(name):
    r = name.split('.')[1]
    if r=="mp3":
        music(name)
    elif r=="mp4":
        move(name)
    else:
        print("%s is error!"%name)

lists = ["love.mp3","hate.mp4","cuicui.mp3","nnnn.mp4"]

threads = []
files = range(len(lists))
for i in files:
    t = threading.Thread(target=player,args=(lists[i],))
    threads.append(t)

if __name__ == '__main__':
    for i in files:
        threads[i].start()
    for i in files:
        threads[i].join()
    print ('all end: %s' %ctime())

生产者与消费者示例：

import threading
class Produce(threading.Thread):

    def __init__(self,name):
        threading.Thread.__init__(self)
        self.name = name
    def run(self):
        global x
        tt.acquire()
        if x > 0 :

            print("我不生产了")
        else:
            for i in range(5):
                x += 1
                print("%s在生产中，第%d个"%(self.name,x))
        tt.release()

class Consume(threading.Thread):
    def __init__(self,name):
        threading.Thread.__init__(self)
        self.name = name
    def run(self):
        global x
        tt.acquire()
        if x == 0:

            print("我不消费了")
        else:
            for i in range(5):
                x -= 1
                print("%s在消费中，第%d个"%(self.name,x+1))
        tt.release()
x = 0
tt = threading.Lock()
# tt = threading.Condition

p = Produce("produce")
c = Consume("consume")

p.start()
c.start()

p.join()
c.join()