# Copyright (c) 2007, Enthought, Inc. # License: BSD Style. # add_class_trait.py --- Example of mutually-referring classes # using add_class_trait() #--[Imports]-------------------------------------------------------------------- from traits.api import HasTraits, Instance #--[Code]----------------------------------------------------------------------- # Defining mutually-referring classes using add_class_trait() class Chicken ( HasTraits ): pass class Egg ( HasTraits ): created_by = Instance( Chicken ) # Now that 'Egg' is defined, we can add the 'hatched_from' trait to # solve the mutual-reference problem... Chicken.add_class_trait( 'hatched_from', Instance( Egg ) )