title: Can I get a lint error on implicit string joining in python?
body: <p>Is there some way to get lint error on missed commas in literal list of strings?</p>
  
  <p><strong>Example:</strong></p>
  
  <pre><code>exceptions = ["banana", "pineapple", "apple"
                "pen"]
  </code></pre>
  
  <p>You may think this list contains 4 items, but truth be told! "apple" and "pen" are joined into "applepen".</p>
  
  <p>I'm terrified of these omitted commas. Is there some lint tool to help me find them?</p>
  
  <p><strong>Example 2:</strong></p>
  
  <pre><code>exceptions = ["Carmichael",
                "Vanessa"      # &lt;--- Spot the missing comma
                "Ford"]
  </code></pre>