title: An efficient way of replacing list of keys with dict values?
body: <p>Say I have a list of keys belonging in a dictionary:</p>
  
  <pre><code>dict = {"a":[1,2], "b":[3,4], "c":[5,6]}
  keys = ["a","b","c"]
  </code></pre>
  
  <p>What's the most efficient way to replace all the keys in the list with the values in the dictionary?</p>
  
  <p>ie,</p>
  
  <pre><code>keys = ["a","b","c"]
  </code></pre>
  
  <p>becomes</p>
  
  <pre><code>keys = [[1,2],[3,4],[5,6]]
  </code></pre>