Do scipy sparse matrixes have the same slicing semantics as numpy arrays? I would expect the same slice of a numpy array and a scipy array to have the same shape. In this simple test, they do not. I'm using scipy 0.10. >>> d = numpy.zeros( (4,3) ) >>> s = scipy.sparse.lil_matrix(d) >>> d[:,0].shape == s[:,0].shape False Bug or feature? -matt