title: removing duplicate entries from multi-d array in python
body: <p>I have a 2-d array</p>
  
  <pre><code> xx=[[a,1],[b,2],[c,3]]
  </code></pre>
  
  <p>Now I'm trying to remove duplicate entries from it. For simple 1-D array, simple code like</p>
  
  <pre><code>xx=list(set(xx))
  </code></pre>
  
  <p>would work. But trying set on 2-d elements gives an error</p>
  
  <pre><code>temp = set(xx)
  TypeError: unhashable type: 'list'
  </code></pre>
  
  <p>One workaround would be to serialize xx elements, and then do a list(set()) on new array and then unserialize all the elements back again.</p>
  
  <p>Is there any solution in python?</p>