class conversion.py

class A(object):
    def id(self):
        return "Hello"

class B(object):
    def id(self):
        return "Hi"

dict1 = {}
dict2 = {}
storedVar = A()
print "Unstored: %s" % (storedVar.id(),)

dict1['foo'] = storedVar
dict2['bar'] = storedVar
storedVar = None

print "Dict 1: %s" % (dict1['foo'].id(),)
# Prints "Dict 1: Hello"
print "Dict 2: %s" % (dict2['bar'].id(),)
# Prints "Dict 2: Hello"

print "Changing class"

dict1['foo'].__class__ = B

print "Dict 1: %s" % (dict1['foo'].id(),)
# Prints "Dict 1: Hi"
print "Dict 2: %s" % (dict2['bar'].id(),)
# Prints "Dict 2: Hi"

print "Magic!"