def _extract_rgb(self, rgb):
        clen = lambda x: np.array([len(zlib.compress(x.tostring()))])
        return np.hstack(map(clen, [rgb, rgb[:, :, 0], rgb[:, :, 1],
                                    rgb[:, :, 1] - rgb[:, :, 0]])).reshape(1, -1)
dataset/ETHPy150Open ChrisBeaumont/brut/bubbly/extractors.py/CompressionExtractor._extract_rgb/swapped operands of `-`