Can a linked list class in python take a 'next' value in the constructor?

For convenience, I’d like to use a linked list Node class like the following:

a = Node(3)
b = Node(2, a)
c = Node(1, b) # c = (1) -> (2) -> (3)

I’ve tried the following class definition

class Node:
    def __init__(self, val: int, next_node: Node = None):
        self.val = val
        self.next = next_node

… but I’m getting a NameError about Node in the constructor.

I recognize that this is recursive, but nevertheless I’ve seen this done in other languages. Is this possible in Python?

>Solution :

Use typing.Self to refer to the Node type.

from typing import Self
class Node:
    def __init__(self, val: int, next_node: Self = None):

Alternatively, use the string 'Node'.