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()