関連ワード:  2d numpy array to 1d    2d np array to 1d    numpy 2d array to 1d list    flatten 2d numpy array to 1d    reshape 2d numpy array to 1d    numpy 2d matrix to 1d    python numpy 2d array to 1d    numpy 2d array into 1d    make 2d numpy array 1d    numpy collapse 2d array to 1d