Method update

recipes/Python/578484_Observer_Pattern/recipe-578484.py:44–45

(self, subject, attrname, value)

class Observer1:
    def update(self, subject, attrname, value):
        print 'Observer1: Subject %s has updated attr %s to %s' % (subject.name, attrname, value)

class Observer2:
    def update(self, subject, attrname, value):