title: How to send argument into bash from python?
body: <pre><code>import os  
  os.system("echo \"Hello World\"") 
  Hello World
  0
  </code></pre>
  
  <p>Now i want to send an argument into echo in python.</p>
  
  <pre><code>name ="ok"
  os.system("echo {name}")
  </code></pre>
  
  <p>The result is <code>{name}</code>,not i expects.<br>
  How to get <code>ok</code> as result?<br>
  How to send argument {name}'s value <code>ok</code> into bash from python?</p>