Попробуйте это:
import numpy as np
A = [[1, 4, 5, 12],
[-5, 8, 9, 0],
[-6, 7, 11, 19],
[11, 3, 2, 12]]
rowRemoval = input("Which row would you like removed?\n")
#Assumes the input can be converted into an integer
rowRemoval = int(rowRemoval)
for i in range(rowRemoval, 4):
A = np.delete(A, rowRemoval, 0)
print (A)