title: python call external program non-blocking way
body: <p>is there a way to call an external program inside python and don't wait for its execution to finish?</p>
  
  <p>I tried this, but no luck:</p>
  
  <pre><code>os.system("external_program &amp;")
  </code></pre>
  
  <p>Normally, if I call <code>external_program &amp;</code> inside a bash shell it executes as a background process.
  How can I do it inside python? For, my special case, creating another thread does not work. After main python scrip is done, the external program should continue its execution.</p>