Find the set difference of two arrays.
Return the unique values in ar1 that are not in ar2.
Input comparison array.
If True, the input arrays are both assumed to be unique, which
can speed up the calculation. Default is False.
1D array of values in ar1 that are not in ar2. The result
is sorted when assume_unique=False, but otherwise only sorted
if the input is sorted.
Module with a number of other functions for performing set operations on arrays.
>>> a = np.array([1, 2, 3, 2, 4, 1])
>>> b = np.array([3, 4, 5, 6])
>>> np.setdiff1d(a, b)