title: python matrix transpose and zip
body: <p>How to get the transpose of this  matrix..Any easier ,algorithmic way to do this...</p>
  
  <p>1st question:</p>
  
  <pre><code> Input  a=[[1,2,3],[4,5,6],[7,8,9]]
   Expected output a=[[1, 4, 7], [2, 5, 8], [3, 6, 9]] 
  </code></pre>
  
  <p>2nd Question:</p>
  
  <p>Zip gives me the following output said below,how can i zip when i dont know how many elements are there in the array,in this case i know 3 elements a[0],a[1],a[2] but how can i zip a[n] elements</p>
  
  <pre><code> &gt;&gt;&gt; zip(a[0],a[1],a[2])
   [(1, 4, 7), (2, 5, 8), (3, 6, 9)]
  </code></pre>