title: directly use MemmapingPool in python joblib module
body: <p>the <code>joblib</code> module has provided a tremendously easy-to-use function <code>Parallel</code> to simplify coding. However, it always gathers all the results before you can access any of them. </p>
  
  <p>I have the need to deal with the results one by one because the results are big arrays taking a lot of memory. They cannot reside in the memory at the same time. So I need to deal with part of them first and then discard. Originally, I used <code>futures.as_completed</code> method from <code>MultiprocessPool</code> so that results can be handled immediately when they are available. </p>
  
  <p>But now I also want to use <code>joblib</code> to manage the <code>memmap</code>ed arrays for me. Does <code>joblib</code> also has the interface like <code>MultiprocessPool</code>? I looked into the code a little and found <code>MemmapingPool</code>. But these is no document and examples on how to use it. </p>
  
  <p>I have the following questions:</p>
  
  <ol>
  <li>Do I use them the same as using <code>MultiprocessPool</code>?</li>
  <li>How to handle <code>Ctrl-C</code> in this case?</li>
  </ol>