title: How do I execute an action which doesn't return anything in parallel for every item in a sequence?
body: <p>This piece of code applies an action in parallel to every element of a sequence:</p>
  
  <pre><code>import multiprocessing
  
  ...
  pool = multiprocessing.Pool(2)
  print(pool.map(action, sequence))
  </code></pre>
  
  <p>How do I run an action in parallel while ignoring its result (or if it doesn't return anything)? Do I need to do it like in the piece of code below—which works but doesn't look right to me—or is there a more elegant method?</p>
  
  <pre><code>import multiprocessing
  
  ...
  pool = multiprocessing.Pool(2)
  list(pool.map(action, sequence))) # Don't assign the result to a variable, since
                                    # it will be just a list of `None`.
  </code></pre>
  
  <p>In other words, how do I do this, but in parallel:</p>
  
  <pre><code>for c in sequence:
      action(c)
  </code></pre>