m）中提取mxm子矩阵？" data-bg="https://pythondict-1252734158.file.myqcloud.com/home/www/pythondict/wp-content/uploads/2023/10/web-4877959_1280-150x100.jpg"> m）中提取mxm子矩阵？">切片NumPy 2d数组，或者如何从nxn数组（n> m）中提取mxm子矩阵？
