numpy刪除指定元素

import numpy as np

>>> a = np.array([11, 22, 33, 4, 5, 6, 7, 8, 9])

>>> b = np.array([11,22,33])

>>> c = np.setdiff1d(a,b)

>>> c

array([4, 5, 6, 7, 8, 9])