Queue
The Queue module implements multi-producer, multi-consumer queues.
def worker():
while True:
item = q.get()
do_work(item)
q.task_done()
# Indicate that a formerly enqueued task is complete. Used by queue consumer threads.
# For each get() used to fetch a task, \
# a subsequent call to task_done() tells the queue that the processing on the task is complete.
q = Queue()
for i in range(num_worker_threads):
t = Thread(target=worker)
t.daemon = True
t.start()
for item in source():
q.put(item)
q.join() #Blocks until all items in the queue have been gotten and processed.
Threading 多線程
使用Threading模块创建线程,直接从threading.Thread继承,然后重写init方法和run方法:
#!/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"
多線程和隊列結合
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import threading
import time
import Queue
SHARE_Q = Queue.Queue() #构造一个不限制大小的的队列
_WORKER_THREAD_NUM = 3 #设置线程个数
class MyThread(threading.Thread) :
def __init__(self, func) :
super(MyThread, self).__init__()
self.func = func
def run(self) :
self.func()
def worker() :
global SHARE_Q
while not SHARE_Q.empty():
item = SHARE_Q.get() #获得任务
print "Processing : ", item
time.sleep(1)
def main() :
global SHARE_Q
threads = []
for task in xrange(5) : #向队列中放入任务
SHARE_Q.put(task)
for i in xrange(_WORKER_THREAD_NUM) :
thread = MyThread(worker)
thread.start()
threads.append(thread)
for thread in threads :
thread.join()
if __name__ == '__main__':
main()
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