text: import numpy as np 
  #appends values to end of arr
  np.append(arr, values)
  #inserts values into arr before index 2
  np.insert(arr, 2, values)
  #deletes row on index 3 of arr
  np.delete(arr, 3, axis=0)
  #deletes column on index 4 of arr
  np.delete(arr, 4, axis=1)