code: def delete(self, model):
          
  
          signals.pre_delete.send(model.__class__, model=model)
  
          param = {'rid_value': self.to_pg(model)[model.rid_field]}
          query = """
                  DELETE FROM {table}
                  WHERE {rid_field} = %(rid_value)s
                  RETURNING {cols};
                  """
  
          query = query.format(
              cols=self.field_cols(model),
              rid_field=model.rid_field,
              table=model.rtype,
          )
  
          result = self.query(query, param=param)
  
          signals.post_delete.send(model.__class__, model=model)
  
          return result
docs: Given a model object instance delete it