Linked Lists - adding new node doesn't work

Question

I have just started learning about linked lists and I can't seem to add a new node using a function. Here is my code:

class Node:

    def __init__(self, data):
        self.data = data
        self.next = None

    def __repr__(self):
        return self.data

class LinkedList:

    def __init__(self, nodes=None):
        self.head = None
        if nodes is not None:
            node = Node(data=nodes.pop(0))
            self.head = node
            # print(self.head)
            for elem in nodes:
                # print(elem)
                node.next = Node(data=elem)
                node = node.next
                # print(node)

    def __repr__(self):
        node = self.head
        nodes = []
        while node is not None:
            nodes.append(node.data)
            node = node.next
        nodes.append("None")
        return " - > ".join(nodes)

    def __iter__(self):
        node = self.head
        while node is not None:
            yield node
            node = node.next

    def add_first(self, node):
        node.next = self.head
        self.head = node


llist = LinkedList(["c"])
llist.add_first("j")
print(llist)

When I run this, I get AttributeError: 'str' object has no attribute 'next'. Why does it not recognise the 'next' from the Node class?

Add node = Node(node) at the start of your add_first function. — Henry Yik
– Henry Yik, Commented Aug 14, 2020 at 3:50

Surya Lohia. · Accepted Answer · 2020-08-14 03:57:46Z

1

You have a minor mistake in your add_first() function.

I think this will help you:

def add_first(self, s):
     node = Node(s)
     node.next = self.head
     self.head = node

answered Aug 14, 2020 at 3:57

Surya Lohia.

4664 silver badges16 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Linked Lists - adding new node doesn't work

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related