The class you have provided is awkward to use, random access is inefficient, it is not compatible with lists or offer a sequence API, it's not subscriptable or iterable, the API exposes an unnecessary "Proxy" class, and the API is more like what I would expect from Java code than Python code.

But even if every one of those problems was fixed, there is still the question, why would somebody choose this LinkedList instead of the fast, efficient built-in list? What advantages does this have?