title: Python - Differences between two lists
body: <p>for practicing purposes, I tried to implement a function that receives two lists as parameters and returns the difference of them. So basically the elements which are the lists have not in common. </p>
  
  <p>I coded the following functions:</p>
  
  <pre><code>list1 = [4,2,5,3,9,11]
  list2 = [7,9,2,3,5,1]
  
  def difference(list1,list2):
      return (list(set(list1) - set(list2)))
  
  difference(list1,list2)
  </code></pre>
  
  <p>AND</p>
  
  <pre><code>def difference_extra_credit(list1,list2):
      return [value for value in list1 if value not in list2]
  
  difference(list1,list2)
  </code></pre>
  
  <p>--> Basically both codes seem to work but I'm currently facing the problem that the lists need to have the same length in order for the functions to work. If the length is not the same, adding for instance an integer of 100 to list 1, it would not be shown as a difference between the lists if you print the functions. </p>
  
  <p>I didn't manage to find a way to modify the code so that the length of the lists doesn't matter.. Does someone has an idea?</p>
  
  <p>Thanks!</p>