I have two lists of tuples and I want to find which elements from the first are in the second one. For example:

elements =
[(903, 468),
 (913, 468),
 (926, 468),
 (833, 470),
 (903, 470),
 (917, 470),
 (833, 833),
 (903, 833),
 (913, 833),
 (917, 833)]

test_elements = 
[(903, 468), 
(913, 468), 
(833, 470), 
(903, 470), 
(833, 833), 
(903, 833)]

and I want to return a boolean mask for the elements in elements that exist in test_elements. I dont understand why np.isin doesnt give the correct result:

list(map(np.all, np.isin(elements, test_elements)))
>>> [True, True, False, True, True, False, True, True, True, False]

which means that (913, 833) should be in test_elements but this is not true

This expesssion however (which I found from another post here) returns the correct mask:

list((np.array(elements)[:,None] == np.array(test_elements)).all(2).any(1))
>>> [True, True, False, True, True, False, True, True, False, False]

What am I missing with np.isin please?