test.py

x = [[1],[1],[1],[-1]]
a = [[-2,-1,-1,-2],[1,-2,2,-1],[-1,-2,-2,-1],[2,-1,1,-2]]
h = 0.1
def K(h,a,x):
    cont = [1,2,3,4]
    k = [h * item for item in cont]
    y = [[item_x[0] + item_k/4] for item_x, item_k in zip(x, k)]
    return y
    
K(h,a,x)