title: Computing average of non-zero values
body: <p>I have lists from whose I what the average of non-zero values.</p>
  
  <p>E.G</p>
  
  <pre><code> [2,2,0,0,0] -&gt; 2    
   [1,1,0,1,0]  -&gt; 1  
   [0,0,0,9,0] -&gt; 9    
   [2,3,0,0,0] -&gt; 2.5
  </code></pre>
  
  <p>Current I'm doing this:</p>
  
  <pre><code>list_ = [1,1,0,1,0]  
  non_zero = [float(v) for v in list_ if v&gt;0]
  averge = sum(non_zero)/len(non_zero)
  </code></pre>
  
  <p>How can I do this operation more efficiently? </p>