code: def set_n(self, value):
          ''' setter '''
          if isinstance(value, int):
              self.__n = value
          else:
              raise TypeError("The type of n must be int."f set_n(self, value):
          ''' setter '''
          if isinstance(value, int):
              self.__n = value
          else:
              raise TypeError("The type of n must be int.")
docs: setter