title: Variable in os.system
body: <p>I am using <code>os.system</code> method in Python to open a file in Linux.
  But I don't know how to pass the variable (a) inside the os.system command</p>
  
  <pre><code>import os
  a=4
  os.system('gedit +a test.txt')
  </code></pre>
  
  <p>How can i pass the variable as an integer inside the command?</p>