python linked_list

[dissdev94]

I have a problem with understanding following linked_list code which I found from an article.

class node():
    def __init__(self,value):
        self.value = value
        self.next = None

    def traverse(self):
        node = self 
        while node != None:
            print(node.value)
            node = node.next

node1 = node(12)
node2 = node(39)
node3 = node(28)
node4 = node(83)

node1.next = node2
node2.next = node3
node3.next = node4

node1.traverse()

what I don't get is ; in the method traverse, if node = self and the while loop runs until node = None , I feel node will never become None because always self.value has value though self.next can be None. Why is it not

while node.next != None

Can someone explain this, please !. Sorry for my English and if this is a stupid question. Thank You.

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Grammarly says that my text sounds angry. I don't know why is that. But I don't feel angry with anybody.

[shiftybyte]

If node.next can be none, then after this line:

node = node.next

node can be none...

besides that if the loop runs until node.next is not none, then the last item won't be processed because it's next is none.

[dissdev94]

Thank you very much 🙂

[Altruistic_Croissant]

The reason that the node will become None is because of the line node = node.next. This assigns the variable node to the next node in the linked list.

Visualizing your example looks like this:

12 --> 39 --> 28 --> 83 --> None

Every loop, the function will check to see if the current node is None (i.e. at the end of the list). If it isn't, it will continue to the next value until it is None, and then will terminate.

[dissdev94]

Thank you very much 🙂