code: def zSetSurfaceData(self, surfNum, radius=None, thick=None, material=None, semidia=None, 
                          conic=None, comment=None):
          
          if self.pMode == 0: # Sequential mode
              surf = self.pLDE.GetSurfaceAt(surfNum)
              if radius is not None:
                  surf.pRadius = radius
              if thick is not None:
                  surf.pThickness = thick
              if material is not None:
                  surf.pMaterial = material
              if semidia is not None:
                  surf.pSemiDiameter = semidia
              if conic is not None:
                  surf.pConic = conic
              if comment is not None:
                  surf.pComment = comment
          else:
              raise NotImplementedError('Function not implemented for non-sequential mode')
docs: Sets surface data