code: def setfillmode(self, fill_mode):
          
  
          if not fill_mode in [SDC.FILL, SDC.NOFILL]:
              raise HDF4Error("bad fill mode")
          old_mode = _C.SDsetfillmode(self._id, fill_mode)
          _checkErr('setfillmode', old_mode, 'cannot execute')
          return old_mode
docs: Set the fill mode for all the datasets in the file.
  
          Args::
  
            fill_mode : fill mode; one of :
                          SDC.FILL   write the fill value to all the datasets
                                    of the file by default
                          SDC.NOFILL do not write fill values to all datasets
                                    of the file by default
  
          Returns::
  
            previous fill mode value
  
          C library equivalent: SDsetfillmode