def get_classes(class_name):
    """get_classes(class_name) -> class_object_list : cast new type class only"""
    cls_list = []
    import gc
    import inspect
    for obj in gc.get_objects():
        try:
            if getattr(obj, '__class__', None):
                if inspect.isclass(obj) and obj.__name__ == class_name:
                    cls_list.append(obj)
        except ReferenceError:
            continue
    return cls_list
