How can I find the index of a tuple inside a numpy array?
It's not means search a tuple('Species2', 'Species3') from groups when you use 
np.where(groups == ('Species2', 'Species3'))
it means search 'Species2' and 'Species3' separately if you have a Complete array like this 
groups=np.array([('Species1',''), ('Species2', 'Species3')], dtype=object)
I have a numpy array as:
groups=np.array([('Species1',), ('Species2', 'Species3')], dtype=object).
When I ask np.where(groups == ('Species2', 'Species3')) or even np.where(groups == groups[1]) I get an empty reply: (array([], dtype=int64),)
Why is this and how can I get the indexes for such an element?