title: python twisted threading
body: <p>Hi can you please tell me how use different functions in different thread using thread pool 
  in twisted...say</p>
  
  <p>I have a list of ids <code>x=[1,2,3,4]</code> where 1,2,...etc are ids(I got from data base and each one contains python script in some where disk).</p>
  
  <p>what I want to do is</p>
  
  <p>scanning of x traverse on list and run every script in different thread until they completed</p>
  
  <hr>
  
  <p>Thanx Calderone, your code helped me a lot.</p>
  
  <p>I have few doubts like I can resize threadpool size by this way. </p>
  
  <pre><code>from twisted.internet import reactor
  reactor.suggestThreadPoolSize(30)
  </code></pre>
  
  <p>say all 30 available threads are busy &amp; there is still some ids in list(dict or tuple)
  1-In this situation all ids will be traversed? I mean as soon as thread is free next tool(id)
  will be assigned to freed thread?
  2-there is also some cases one tools must be executed before second tool &amp; one tool output will be used by another tool,how will it be managed in twisted thread. 3</p>