mat = scipy.sparse.csc_matrix([[1, 2, 3], [2, 3, 4], [3, 4, 5]])
vec = scipy.sparse.csc_matrix([1, 2, 3]).T
mat_row = mat.tocsr()
vec_row = vec.T
mat_row.data -= numpy.repeat(vec_row.toarray()[0], numpy.diff(mat_row.indptr))
print(mat_row.todense())
Efficiently Subtract Vector from Matrix (Scipy)