title: While not in list
body: <p>I'm trying to write a code, and I want to ask you how can I ask a while loop to repeat untill it finds a word, in my case <strong>END</strong> on the list, for example.    </p>
  
  <pre><code>L=[]
  while "END" (not) in L :
     L=L.append(something)
  </code></pre>
  
  <p>Ask me if you don't understand what I mean.</p>