title: Simple async example with tornado python
body: <p>I want find simple async server example. 
  I have got some function with lot of wait, database transactions ... etc:</p>
  
  <pre><code>def blocking_task(n):
      for i in xrange(n):
          print i
          sleep(1)
      return i
  </code></pre>
  
  <p>I need run it function in separated process without blocking. Is it possible?</p>