protopy.py

class PrototypeStore(dict):
    def __setattr__(self, name, value):
        self[name] = value

    def __getattr__(self, name):
        return self[name]

class PrototypeMeta(type):
    def __new__(metacls, cls_name, bases, attrs):
        cls = type.__new__(metacls, cls_name, bases, attrs)
        cls.prototype = PrototypeStore()
        return cls

class Prototype(object):
    __metaclass__ = PrototypeMeta

    def __getattr__(self, name):
        return self.__class__.prototype[name]

class TestClass(Prototype):
    def __init__(self):
        self.a = 10

def run():
    first = TestClass() # Make an object
    first.prototype.x = 7 # Assign 'x' to its prototype
    second = TestClass() # Create another object of the same class
    print second.x # This should print 7, which was assigned to an earlier object
    first.x = 9 # Now lets overwrite 'x' with a local value
    print first.x # This should return 9 and not 7
    del first.x # Removing this should cause a reference back to the 'x' in prototype
    print first.x # This should return 7
    first.prototype.incr = lambda x: x + 1 # Lets try this for functions
    print second.incr(10) # This should return 11

if __name__ == '__main__':
    run()

Good work.