#NEWLINE# def order_by( self , * field_names ) : #NEWLINE# #INDENT# '\n        Returns a new QuerySet instance with the ordering changed.\n        ' #NEWLINE# assert self . query . can_filter ( ) , 'Cannot reorder a query once a slice has been taken.' #NEWLINE# obj = self . _clone ( ) #NEWLINE# obj . query . clear_ordering ( force_empty = False ) #NEWLINE# obj . query . add_ordering ( * self ) #NEWLINE# return obj