线程化和信息传递--如何

Question

为了避免混淆，我编辑了这个问题：

one.py

import threading
count = 5
dev = threading.Thread(name='dev', target=dev,args=(workQueue,count,))
dev.setDaemon(True)
dev.start()
workQueue = Queue.Queue(10)
queueLock.acquire()
workQueue.put(word)
queueLock.release()
count = 3
time.sleep(2)
count = 5

但我在这里的困惑是，我能够在线程之间放置和获取队列中的值，但在计数的情况下，它不会反映。

为什么会这样呢？

我在这里到底遗漏了什么？

class dev ( threading.Thread ):
    def test(self):
        while 1:
            print count
            print self.EPP_Obj
            queueLock.acquire()
            if not self.workQueue.empty():
                data = self.workQueue.get()
                print data
                queueLock.release()
            else:
                queueLock.release()

    def __init__(self, workQueue, EPP_Obj):
        threading.Thread.__init__(self)
        self.workQueue = workQueue
        self.EPP_Obj = EPP_Obj

Answer 1

让我们从一个例子开始：

Thread子类：

import threading

class Dev(threading.Thread):

    def __init__(self, workQueue, queueLock, count):
        super(Dev, self).__init__()   # super() will call Thread.__init__ for you
        self.workQueue = workQueue
        self.queueLock= queueLock
        self.count = count

    def run(self):  # put inside run your loop
        data = ''
        while 1:
            with self.queueLock:
                if not self.workQueue.empty():
                    data = self.workQueue.get()
                    print data
                    print self.count

            if data == 'quit':
                break

with语句是获取和释放锁的一种聪明方法，请看一下doc。

现在运行的代码如下：

import Queue
import time

work_q = Queue.Queue()     # first create your "work object"
q_lock = threading.Lock()
count = 1

dev = Dev(work_q, q_lock, count)  # after instantiate like this your Thread
dev.setDaemon(True)
dev.start()

time.sleep(1)
with q_lock:
    work_q.put('word')
# word
# 1

time.sleep(1)
count = 10
with q_lock:
    work_q.put('dog')
# dog
# 1

count = 'foo'
with q_lock:
    work_q.put('quit')
# quit
# 1

dev.join()   # This will prevent the main to exit
             # while the dev thread is still running

有了上面的代码，我们就有了一个清晰的例子，说明无论我们对count做什么，self.count都保持不变。

这种行为的原因是调用：

dev = Dev(work_q, q_lock, count)

或

dev = Dev(work_q, q_lock, 1)

都是一回事。

Arnold Moon向您展示了一种更改self.count的方法。将其调整为我们的示例：

class Dev(threading.Thread):

    def __init__(self, workQueue, queueLock, count):
        super(Dev, self).__init__()
        self.workQueue = workQueue
        self.queueLock= queueLock
        self.count = count

    def set_count(self, value):
        self.count = value

    def run(self):
        data = ''
        while 1:
            with self.queueLock:
                if not self.workQueue.empty():
                    data = self.workQueue.get()
                    print data
                    print self.count

            if data == 'quit':
                break

在运行代码中调用set_count将更改self.count的值

time.sleep(1)
with q_lock:
    work_q.put('word')
# word
# 1

time.sleep(1)
count = dev.count + 9
dev.set_count(count)
with q_lock:
    work_q.put('dog')
# dog
# 10

count = 'foo'
with q_lock:
    work_q.put('quit')
# quit
# 10
dev.join()

我希望这能帮助你澄清一些疑问。

Answer 2

我希望这能对你有所帮助。我想你不知道你需要用哪种方式。在python中有一些多线程的方法。我介绍了类的使用方法。你在下面的代码中运行。你会明白的。

main.py

import stringRepeater
import Queue

workqueue = Queue.Queue()
workqueue.put('test1')
workqueue.put('test2')
workqueue.put('test3')

th = stringRepeater.stringRepeater(workqueue,5)
th.start()
print '----daemon is on ----'
th.setCount(3)
workqueue.put('test4')
workqueue.put('test5')

stringRepeater.py

import threading

class stringRepeater(threading.Thread):
    def __init__(self, workQueue, count):
        threading.Thread.__init__(self)
        self.workQueue = workQueue
        self.repeatCount = count

    def run(self):
        while True:
            teststring = self.workQueue.get()
            for i in range(self.repeatCount):
                print teststring

    def setCount(self, newcount):
        self.repeatCount = newcount