linkedList.py

class Node:
    data = None
    next_node = None

    def __init__(self, data):
        self.data = data

    def __repr__(self):
        return "<Node data: %s>" %self.data

N1 = Node(23)
print(N1)

class LinkedList:
    """
    Singly linked list
    """
    #head = None
    def __init__(self):
        self.head = None

    def is_empty(self):
        return self.head == None

    def size(self):
        current = self.head
        count = 0

        while current:
            count +=1
            current = current.next_node

        return count
    
    def add(self, data):
        new_node = Node(data)
        new_node.next_node = self.head
        self.head = new_node
    
    def search(self, key):
        current = self.head

        while current:
            if current.data == key:
                return current
            else:
                current = current.next_node
        return None

    def insert(self, data, index):
        if index == 0:
            self.add(data)
        
        if index > 0:
            new = Node(data)

            position = index
            current = self.head
            while position > 1:
                current = Node.next_node
                position -= 1
            
            prev_node = current
            next_noode = current.next_node

            prev_node.next_node = new
            new.next_node = next_noode
    
    def remove(self, key):
        current = self.head
        previous = None
        found = False

        while current and not found:
            if current.data == key and current is self.head:
                found = True
                self.head = current.next_node
            elif current.data == key:
                found = True
                previous.next_node = current.next_node
            else:
                previous = current
                current = current.next_node
        return current

    def __repr__(self):
        nodes =[]
        current = self.head

        while current:
            if current is self.head:
                nodes.append("[Head: %s]" %current.data)
            elif current.next_node is None:
                nodes.append("[Tail: %s]" % current.data)
            else:
                nodes.append("[%s]" %current.data)

            current= current.next_node
        return '->'.join(nodes)