message: Added to_sparse_matrix() to python bindings
diff: @@ -143,6 +143,16 @@ void bind_quantum(py::module &m) {
  }
  return mat;
  })
  + .def("to_sparse_matrix", [](PauliOperator& op) {
  + auto mat_el = op.to_sparse_matrix();
  + std::vector<std::tuple<std::uint64_t, std::uint64_t, std::complex<double>>> triplets(mat_el.size());
  + int counter = 0;
  + for (auto el : mat_el) {
  + std::tuple<std::uint64_t, std::uint64_t, std::complex<double>> triplet{el.row(), el.col(), el.coeff()};
  + triplets[counter++] = triplet;
  + }
  + return triplets;
  + })
  .def(
  "__iter__",
  [](PauliOperator &op) {
  