title: executing command line, hide return and save it
body: <p>If I run this below I am shown the return straight away on screen</p>
  
  <pre><code>   #!/usr/bin/python3    
      import os    
      myVar = os.system('echo, Hello')
  </code></pre>
  
  <blockquote>
  <pre><code> Hello
  </code></pre>
  </blockquote>
  
  <p>How do I stop it being shown but save the result for use later? 
  I expected to be able to print the results using <code>print (("%s")% myVar)</code> but that just returns <code>0</code> </p>