title: Python Find permutable list in a dict list
body: <p>Given</p>
  <pre><code>listOfDict = [{'ref': 1, 'a': 1, 'b': 2, 'c': 3},
                {'ref': 2, 'a': 4, 'b': 5, 'c': 6},
                {'ref': 3, 'a': 7, 'b': 8, 'c': 9}]
  </code></pre>
  <p>Lets' consider a list of permutable integer</p>
  <pre><code>[7,8,9]=[7,9,8]=[8,7,9]=[8,9,7]=[9,7,8]=[9,8,7] # (3!)
  </code></pre>
  <p>Each of this list has a unique mapping ref, so how given for <code>(8,7,9)</code> can I get <code>ref=3</code> ?</p>
  <p>Also in real case I might until 10 (a,b,c,d,e,f,g,h,i,j)...</p>