title: Python - Using Lambda in List.Sort
body: <p>I am trying to sort a list of lists based on the 2nd element in the sub list.</p>
  
  <p>Sample  Data:</p>
  
  <pre><code> [[u'm3u33mm534o', 14, 23], [u'2w3dfbv333g', 20, 34], [u'7kv903nfjfr9', 0, 35]]
  </code></pre>
  
  <p>Sort:</p>
  
  <pre><code> out.sort(key=lambda x: float(x[1]))
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>TypeError: float() argument must be a string or a number
  </code></pre>
  
  <p>What is the issue here?</p>