title: Finding the index of an element in nested lists in python
body: <p>I am trying to get the index of an element in nested lists in python - for example <code>[[a, b, c], [d, e, f], [g,h]]</code> (not all lists are the same size).
  I have tried using </p>
  
  <pre><code>strand_value= [x[0] for x in np.where(min_value_of_non_empty_strands=="a")]
  </code></pre>
  
  <p>but this is only returning an empty list, even though the element is present. Any idea what I'm doing wrong?</p>