多线程。线程异常

Question

我想用example来理解。下面的代码：

import Queue 
import threading 
import urllib2 
import time 
from BeautifulSoup import BeautifulSoup 

hosts = ["http://yahoo.com", "http://google.com", "http://amazon.com", 
"http://ibm.com", "http://apple.com"] 

queue = Queue.Queue() 
out_queue = Queue.Queue() 

class ThreadUrl(threading.Thread): 
    """Threaded Url Grab""" 
    def __init__(self, queue, out_queue): 
     threading.Thread.__init__(self) 
     self.queue = queue 
     self.out_queue = out_queue 

    def run(self): 
     while True: 
      #grabs host from queue 
      host = self.queue.get() 

      #grabs urls of hosts and then grabs chunk of webpage 
      url = urllib2.urlopen(host) 
      chunk = url.read() 

      #place chunk into out queue 
      self.out_queue.put(chunk) 

      #signals to queue job is done 
      self.queue.task_done() 

class DatamineThread(threading.Thread): 
    """Threaded Url Grab""" 
    def __init__(self, out_queue): 
     threading.Thread.__init__(self) 
     self.out_queue = out_queue 

    def run(self): 
     while True: 
      #grabs host from queue 
      chunk = self.out_queue.get() 

      #parse the chunk 
      soup = BeautifulSoup(chunk) 
      print soup.findAll(['title']) 

      #signals to queue job is done 
      self.out_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, out_queue) 
     t.setDaemon(True) 
     t.start() 

    #populate queue with data 
    for host in hosts: 
     queue.put(host) 

    for i in range(5): 
     dt = DatamineThread(out_queue) 
     dt.setDaemon(True) 
     dt.start() 


    #wait on the queue until everything has been processed 
    queue.join() 
    out_queue.join() 

main() 
print "Elapsed Time: %s" % (time.time() - start) 

有时候，我得到这个错误在这里：

异常螺纹加工-10（翻译关闭期间最有可能上调）

解释请什么原因造成的。

更新由其他作者：

下面是完整的例外，我在类似的代码，请参阅：

Exception in thread Thread-1 (most likely raised during interpreter shutdown): 
Traceback (most recent call last): 
    File "/usr/local/lib/python2.7/threading.py", line 552, in __bootstrap_inner 
    File "/usr/local/lib/python2.7/threading.py", line 505, in run 
    File "mine.py", line 86, in run 
    File "/usr/local/lib/python2.7/Queue.py", line 168, in get 
    File "/usr/local/lib/python2.7/threading.py", line 237, in wait 
<type 'exceptions.TypeError'>: 'NoneType' object is not callable 

Answer 1

你的示例脚本似乎好 - 这是说，它运行良好我使用python的2.7.2。

你使用的是什么版本的Python？您可能看到的错误可能与this bug有关。如果是这样，那么升级到python> = 2.6.5或python> = 3.1可能会有所帮助。

Answer 2

这是错误http://bugs.python.org/issue14623

最简单的解决方法是增加超时

time.sleep(1) 

在脚本的末尾，允许线程完成了剧本来结束生命之前，靠近