Prototype design pattern in python

prototype.py

class Prototype(object):

    value = 'default'

    def clone(self, **attrs):
        """Clone a prototype and update dictionary"""
        obj = self.__class__()
        obj.__dict__.update(attrs)
        return obj


class PrototypeDispatcher(object):
    def __init__(self):
        self._objects = {}

    def get_objects(self):
        """Get all objects"""
        return self._objects

    def register_object(self, name, obj):
        """Register an object"""
        self._objects[name] = obj

    def unregister_object(self, name):
        """Unregister an object"""
        del self._objects[name]
    
if __name__ == '__main__':   
    dispatcher = PrototypeDispatcher()
    prototype = Prototype()

    obj1 = prototype.clone()
    obj2 = prototype.clone(value='Obj 2', category='a')
    obj3 = prototype.clone(value='Obj 3', is_checked=True)    
    dispatcher.register_object('default', obj1)
    dispatcher.register_object('object2', obj2)
    dispatcher.register_object('object3', obj3)

    #print objects
    for k,v in dispatcher.get_objects().items():
        print(k + ':' + v.value)

#OUTPUT
#default:default
#object2:Obj 2
#object3:Obj 3