请使用python写出高斯消元法的代码

以下是高斯消元法的Python代码：

def gauss_elimination(A, b):
    n = len(A)
    # 前向消元
    for i in range(n):
        # 选取主元
        pivot = A[i][i]
        for j in range(i+1, n):
            if abs(A[j][i]) > abs(pivot):
                pivot = A[j][i]
                A[i], A[j] = A[j], A[i]
                b[i], b[j] = b[j], b[i]
        # 消元
        for j in range(i+1, n):
            factor = A[j][i] / A[i][i]
            for k in range(i+1, n):
                A[j][k] -= factor * A[i][k]
            b[j] -= factor * b[i]
    # 回带求解
    x = [0] * 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

其中，A为系数矩阵，b为常数向量，返回值为解向量x。