Добавление в конец двухмерного массива

# Sutherland-Hodgman algorithm for clipping
def clip(subject_polygon, clip_polygon):
 
    def intersection():
        dc = [cp1[0] - cp2[0], cp1[1] - cp2[1]]
        dp = [s[0] - e[0], s[1] - e[1]]
        n1 = cp1[0] * cp2[1] - cp1[1] * cp2[0]
        n2 = s[0] * e[1] - s[1] * e[0]
        n3 = 1.0 / (dc[0] * dp[1] - dc[1] * dp[0])
        return ((n1 * dp[0] - n2 * dc[0]) * n3, (n1 * dp[1] - n2 * dc[1]) * n3)
 
    def inside(p):
        return (cp2[0] - cp1[0]) * (p[1] - cp1[1]) > (cp2[1] - cp1[1]) * (p[0] - cp1[0])
 
    clipping_out = input_list = subject_polygon
    cp1 = clip_polygon[-1]
 
    for clip_node in clip_polygon:
        cp2 = clip_node
        input_list = clipping_out
        clipping_out = []
        s = input_list[-1]
 
        for subject_node in input_list:
            e = subject_node
            if inside(e):
                if not inside(s):
                    clipping_out.append(intersection())
                clipping_out.append(e)
            elif inside(s):
                clipping_out.append(intersection())
            s = e
        cp1 = cp2
 
    return clipping_out
 
a = [(50, 150), (200, 50), (350, 150),(350, 300), (250, 300), (200, 250),(150, 350), (100, 250), (100, 200)]
b = [(100, 100), (300, 100),(300, 300), (100, 300)]
print(clip(a, b))