我想在python中使用线程来下载大量的网页,并通过下面的代码使用队列中的一个网站。使用队列的Python中的线程
它放置了一个无限的while循环。每个线程是否连续运行直到所有线程都完成?我错过了什么。
#!/usr/bin/env python
import Queue
import threading
import urllib2
import time
hosts = ["http://yahoo.com", "http://google.com", "http://amazon.com",
"http://ibm.com", "http://apple.com"]
queue = Queue.Queue()
class ThreadUrl(threading.Thread):
"""Threaded Url Grab"""
def __init__(self, queue):
threading.Thread.__init__(self)
self.queue = queue
def run(self):
while True:
#grabs host from queue
host = self.queue.get()
#grabs urls of hosts and prints first 1024 bytes of page
url = urllib2.urlopen(host)
print url.read(1024)
#signals to queue job is done
self.queue.task_done()
start = time.time()
def main():
#spawn a pool of threads, and pass them queue instance
for i in range(5):
t = ThreadUrl(queue)
t.setDaemon(True)
t.start()
#populate queue with data
for host in hosts:
queue.put(host)
#wait on the queue until everything has been processed
queue.join()
main()
print "Elapsed Time: %s" % (time.time() - start)
请检查您的缩进。我试图纠正它,但'queue.join'的方式错位,它也可能在顶层。您将主机添加到队列的循环也在您创建线程的循环中,因此您将每个主机添加五次。 – mata
随着缩进校正,脚本也适用于我。 – lukedays
此代码看起来像是通过[here](http://www.ibm.com/developerworks/aix/library/au-threadingpython/) – daviewales