title: Python Random List Comprehension
body: <p>I have a list similar to:</p>
  
  <pre><code>[1 2 1 4 5 2 3 2 4 5 3 1 4 2] 
  </code></pre>
  
  <p>I want to create a list of x random elements from this list where none of the chosen elements are the same. The difficult part is that I would like to do this by using list comprehension...
  So possible results if x = 3 would be:</p>
  
  <pre><code>[1 2 3]
  [2 4 5]
  [3 1 4]
  [4 5 1]
  </code></pre>
  
  <p>etc...</p>
  
  <p>Thanks!</p>
  
  <p>I should have specified that I cannot convert the list to a set.  Sorry!
  I need the randomly selected numbers to be weighted.  So if 1 appears 4 times in the list and 3 appears 2 times in the list, then 1 is twice as likely to be selected...</p>