Простая программа на Python. Помогите написать

 import numpy as np 
 
# Прямой ход 
def forward_elimination(A, b): 
    n = len(A) 
    for i in range(n): 
        max_row = i 
        for k in range(i + 1, n): 
            if abs(A[k][i]) > abs(A[max_row][i]): 
                max_row = k 
 
        A[i], A[max_row] = A[max_row], A[i] 
        b[i], b[max_row] = b[max_row], b[i] 
 
        for k in range(i + 1, n): 
            factor = A[k][i] / A[i][i] 
            A[k][i] = 0 
            for j in range(i + 1, n): 
                A[k][j] -= factor * A[i][j] 
            b[k] -= factor * b[i] 
    return A, b 
 
# Обратный ход 
def back_substitution(A, b): 
    n = len(A) 
    x = np.zeros(n) 
    for i in range(n - 1, -1, -1): 
        x[i] = b[i] 
        for j in range(i + 1, n): 
            x[i] -= A[i][j] * x[j] 
        x[i] /= A[i][i] 
    return x 
 
# Проверка точности 
def check_accuracy(A, b, x): 
    b_calc = np.dot(A, x) 
    return np.allclose(b, b_calc) 
 
# Основная функция для решения СЛАУ 
def solve_slae(A, b): 
    A, b = forward_elimination(A, b) 
    x = back_substitution(A, b) 
    if check_accuracy(A, b, x): 
        return x 
    else: 
        return None 
 
# Пример использования 
A = [[2, 1, -1], [-3, -1, 2], [-2, 1, 2]] 
b = [8, -11, -3] 
solution = solve_slae(A, b) 
 
if solution is not None: 
    print("Решение СЛАУ:", solution) 
else: 
    print("Решение СЛАУ не найдено с заданной точностью.")