title: Python List Iteration into One-Liner
body: <p>I'm currently learning Python. </p>
  
  <p>How do I put this:</p>
  
  <pre><code>dates = list()  
  for entry in some_list:  
      entry_split = entry.split()    
      if len(entry_split) &gt;= 3:  
          date = entry_split[1]
          if date not in dates:  
              dates.append(date)
  </code></pre>
  
  <p>into a one-liner in Python?</p>