title: Joining 2 list of different size in Python
body: <p>I get "list of index out of range" error when try to use 2 different size list.</p>
  
  <p>example:</p>
  
  <pre><code>ListA = [None, None, None, None, None]
  ListB = ['A', None, 'B']
  
  for x, y in enumerate(ListA):
      if ListB[x]:
          ListA[x]=ListB[x]
  </code></pre>
  
  <p>Doing this will get "list of index out of range" error, because ListB[3] and ListB[4] does not exist:<br>
  I hope to join ListA and ListB to get ListA look like this:</p>
  
  <pre><code>ListA = ['A', None, 'B', None, None]
  </code></pre>
  
  <p>How can I achieve that?</p>