code: def pauli_basis(nq=1):
      
      basis = tensor_product_basis(*[
          TomographyBasis(
              gell_mann_basis(2).data[[0, 2, 3, 1]],
              [2],
              [u'𝟙', r'\sigma_x', r'\sigma_y', r'\sigma_z']
          )
      ] * nq)
  
      basis._name = 'pauli_basis'
      return basis
docs: Returns a TomographyBasis for the Pauli basis on ``nq``
      qubits.
  
      :param int nq: Number of qubits on which the returned
          basis is defined.