Hi Elsakori,
no, you cannot. You CAN export the whole matrix to scipy (using mat.CSR() or mat.COO()), and get the sub-matrices view scipy.
Within NGSolve we can invert sub-matrices, as we need for preconditioning. Either one 'large' one using sparse direct factorization, or many 'small' ones using dense matrix operations, see more in the tutorials:
ngsolve.org/docu/latest/i-tutorials/unit...obi/blockjacobi.html
Joachim
PS: you missed the attachment