node-where | A very simple geolocation library in node.js | Runtime Evironment library

I have read the posts below but they do not answer my issue.

Post 1

Post 2

Post 3

This post comes close to explaining. The top voted answer by @Rishikesh Raje, says that deleting the last node in a singly-linked list is

[...] is generally not possible.

Why is it generally not possible and not just "it's impossible"? My questions is both in the theory itself and how that applies to Python? The question was meant for C.

Moreover, my other question is for the case where the linked list only has one node which also makes it the last node.

Background: I am solving this problem on LeetCode. Although it doesn't ask for the case of deleting the last case, I tried it but can't seem to get it because of some feature I can't pinpoint. Some direction here would be much appreciated. I added a method to print values for debugging.

Here's the question:

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, the linked list should become 1 -> 2 -> 4 after calling your function.

My code can achieve the required result 1 -> 2 -> 4: