title: finding all the indices of with a value in a list of lists
body: <p>I am trying to find all the indices that have the same values in a list.
  but in my list, there are lists inside the list and I don't know how to do it
  I found how to do that for a normal list:</p>
  <pre><code>list=[2,5,9,1,3,1]
  
  list.index(1)
  </code></pre>
  <p>it will print the indices of value</p>
  <p><code>1: [3,5]</code></p>
  <p>but for this list:</p>
  <pre><code>list=[1, [2,3,17] , 3 , [0,1,2,7,3] , 2 ]
  </code></pre>
  <p>for the value <code>2</code></p>
  <p>it will need to print: <code>[[1, 0], [3, 2], [4]]</code>
  but I don't know how to do that for this kind of list.</p>