title: Python: Produce list which is a sum of two lists, item-wise
body: <p>Say I have two lists:</p>
  
  <pre><code>a=[1,2,3,4,5]
  b=[5,4,3,2,1]
  </code></pre>
  
  <p>I want to create a third one which will be linear sum of two given: </p>
  
  <pre><code>c[i]==a[i]+b[i]
  c==[6,6,6,6,6]
  </code></pre>
  
  <p>Is it possible to do with 'for' constructor? Like: </p>
  
  <pre><code>c = [aa+bb for aa in a for bb in b]
  </code></pre>
  
  <p>(which obviously returns not what I want)</p>