code: def reset_to_coefficients(self):
          
          # Development note: The coefficient attributes are
          # defined in self.__coefficients__
          [setattr(self, key, None)
           for key in self.get_DataFrame(
               data=False,
               with_unit=False,
               with_population=False)
           if key not in self.__coefficients__]
          return self
docs: Keeps only the coefficient.
  
          This can be used to recalculate the IO tables for a new finald demand.
  
          Note
          -----
  
          The system can not be reconstructed after this steps
          because all absolute data is removed. Save the Y data in case
          a reconstruction might be necessary.