>>> A = np.array([4,7,2])
>>> A == 4
array([ True, False, False], dtype=bool)
>>> A < 5
array([ True, False, True], dtype=bool)
>>>
>>> B = np.array([
... [42, 56, 89, 65],
... [99, 88, 42, 12],
... [55, 42, 17, 18]])
>>>
>>> B < 42
array([[False, False, False, False],
[False, False, False, True],
[False, False, True, True]], dtype=bool)
>>>
>>> A = np.array([
... [-1, 2, 1, -1],
... [1, -2, 0, 1],
... [2, -1, -1, 1]])
>>> B[A<0]
array([42, 65, 88, 42, 17])