title: Intersection of two nested lists in Python
body: <p>I've a problem with the nested lists. I want to compute the lenght of the intersection of two nested lists with the python language. My lists are composed as follows:</p>
  
  <pre><code>list1 = [[1,2], [2,3], [3,4]]
  list2 = [[1,2], [6,7], [4,5]]
  output_list = [[1,2]]
  </code></pre>
  
  <p>How can i compute the intersection of the two lists?</p>