title: How can I find the index of a tuple inside a numpy array?
body: <p>I have a numpy array as:</p>
  
  <p><code>groups=np.array([('Species1',), ('Species2', 'Species3')], dtype=object)</code>.</p>
  
  <p>When I ask <code>np.where(groups == ('Species2', 'Species3'))</code> or even <code>np.where(groups == groups[1])</code> I get an empty reply: <code>(array([], dtype=int64),)</code></p>
  
  <p>Why is this and how can I get the indexes for such an element?</p>