class Critter(object): 
    '''A virtual pet''' 
    def __init__(self, name): 
        print 'A new critter has been born!' 
        self.__name = name 
 
    def get_name(self): 
        return self.__name 
 
    def set_name(self, new_name): 
        if new_name == '': 
            print 'A critter's name can't be the empty string.' 
        else: 
            self.__name = new_name 
            print 'Name change successful.' 
 
    name = property(get_name, set_name) 
 
    def talk(self): 
        print '\nHi, I'm', self.name 
 
# main 
crit = Critter('Poochie') 
crit.talk() 
 
print '\nMy critter's name is:', 
print crit.name 
print '\nAttempting to change my critter's name.' 
crit.name = '' 
print '\nAttempting to change my critter's name again.' 
crit.name = 'Randolph' 
 
crit.talk()