arr = array([1,2,3,4,5,6,7,8,9,10])

arr[arr>5]

array([6,7,8,9,10])

>>> import numpy as np
>>> a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
>>> a
array([ 1,  2,  3,  4,  5,  6,  7,  8,  9, 10])

>>> mask = a > 5
>>> mask
array([False, False, False, False, False,  True,  True,  True,  True,
        True])

>>> a[0]
1

>>> a[mask]
array([ 6,  7,  8,  9, 10])