title: python pass variable through os.system
body: <p>This gets the latest mp3 file in my Directory</p>
  
  <pre><code>new_file = [(os.path.getmtime(ft) , os.path.basename(ft))
              for ft in os.listdir(path) if ft.lower().endswith('.mp3')]
  
  new_file.sort()
  </code></pre>
  
  <p>Assigning the latest file to the file I am going to play </p>
  
  <pre><code>playFile = new_file[0][1]
  </code></pre>
  
  <p>Getting the Directory for the file.</p>
  
  <pre><code>PlayfileDir = os.getcwd() + '\\' + str(playFile)
  </code></pre>
  
  <p>Playing the file. This is where I get the error 'PlayfileDir' cannot be found.             </p>
  
  <pre><code>os.system('start "PlayfileDir"')
  </code></pre>