title: Find non-common elements in lists
body: <p>I'm trying to write a piece of code that can automatically factor an expression. For example, 
  if I have two lists [1,2,3,4] and [2,3,5], the code should be able to find the common elements in the two lists, [2,3], and combine the rest of the elements together in a new list, being [1,4,5]. </p>
  
  <p>From this post: <a href="https://stackoverflow.com/questions/3697432/python-how-to-find-list-intersection">How to find list intersection?</a>
  I see that the common elements can be found by </p>
  
  <pre><code>set([1,2,3,4]&amp;set([2,3,5]). 
  </code></pre>
  
  <p>Is there an easy way to retrieve non-common elements from each list, in my example being [1,4] and [5]?</p>
  
  <p>I can go ahead and do a for loop:</p>
  
  <pre><code>lists = [[1,2,3,4],[2,3,5]]
  conCommon = []
  common = [2,3]
  for elem in lists:
      for elem in eachList:
      if elem not in common:
          nonCommon += elem
  </code></pre>
  
  <p>But this seems redundant and inefficient. Does Python provide any handy function that can do that? Thanks in advance!!</p>