title: How To Merge 3 lists into one dictionary(with unique elements)
body: <h3>Code Written In Python</h3>
  <blockquote>
  <p><code># Following Are The 3 Lists</code><br />
  <code>sections = ['A', 'B', 'A', 'A', 'B']</code><br />
  <code>students = ['Jack', 'Jim', 'Jack', 'Leena', 'Jim']</code><br />
  <code>subjects = ['Maths', 'Biology', 'Chemistry', 'English', 'Physics']</code></p>
  <p><code># The Output Should Be A Dictionary</code><br />
  <code>classDict = {'A':{'Jack' :{1:'Maths', 2:'Chemistry'}, 'Leena':{1:'English'}}, 'B':{'Jim':{1:'Biology', 2:'Physics'}}}</code></p>
  </blockquote>
  <p>I can merge any of the two list into one dictionary, taking only first two lists in account</p>
  <pre><code>classDict = {}   
  for stu in students:  
      if not stu in classDict:     
          classDict[stu] = []    
      classDict[stu].append(stu)  
  </code></pre>
  <p>But unable to extend it to n(n=3, in my case) list.</p>