title: creating a sublist from a list in python
body: <p>please help me, i want to write a function that takes a list as an argument and returns a new list of elements that appear more than once from the original list. I tried writing it this way but it doesn't give me the answer</p>
  
  <pre><code>def list(n):
      l = [ ]
      for s in n:
          if n.count(s) &gt; 1:
              l.append(s)
          return l
      return None
  </code></pre>