title: python: padding with zero in the end of every array in Numpy array of arrays
body: <p>I have a Numpy array of arrays and each array inside the main array has a different size. I need to pad the end with 0s at each array so that all arrays that are inside the main array are of equal length but I do not know the max length. I want it to be done in a cleaner way instead of finding the max length and assigning 0's at the end as and when required. a below is already a Numpy aray</p>
  
  <pre><code>a=[
     [1,2,3,4],
     [3,56],
     [8,4,8,4,9,33,55]
    ] .
     In this case maxlength is 7(the length of third array) . 
     I want final array to look like follows 
  a=[
     [1,2,3,4,0,0,0],
     [3,56,0,0,0,0,0],
     [8,4,8,4,9,33,55]
    ]
  </code></pre>