async def update(self, obj, only=None):
        """Update the object in the database. Optionally, update only
        the specified fields. For creating a new object use :meth:`.create()`

        :param only: (optional) the list/tuple of fields or
                     field names to update
        """
        field_dict = dict(obj.__data__)
        pk_field = obj._meta.primary_key

        if only:
            self._prune_fields(field_dict, only)

        if obj._meta.only_save_dirty:
            self._prune_fields(field_dict, obj.dirty_fields)

        if obj._meta.composite_key:
            for pk_part_name in pk_field.field_names:
                field_dict.pop(pk_part_name, None)
        else:
            field_dict.pop(pk_field.name, None)

        query = obj.update(**field_dict).where(obj._pk_expr())
        result = await self.execute(query)
        obj._dirty.clear()
        return result
async def update ( self , obj , only = None ) : field_dict = dict ( obj . __data__ ) pk_field = obj . _meta . primary_key if only : self . _prune_fields ( field_dict , only ) if obj . _meta . only_save_dirty : self . _prune_fields ( field_dict , obj . dirty_fields ) if obj . _meta . composite_key : for pk_part_name in pk_field . field_names : field_dict . pop ( pk_part_name , None ) else : field_dict . pop ( pk_field . name , None ) query = obj . update ( ** field_dict ) . where ( obj . _pk_expr ( ) ) result = await self . execute ( query ) obj . _dirty . clear ( ) return result
Update the object in the database. Optionally, update only
        the specified fields. For creating a new object use :meth:`.create()`

        :param only: (optional) the list/tuple of fields or
                     field names to update