A simple linked list implementation with some basic functionalities

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

class LinkedList:
    def __init__(self, value):
        new_node = Node(value)
        self.head = new_node
        self.tail = new_node
        self.length = 1

    def print_list(self):
        temp = self.head
        while temp is not None:
            print(temp.value)
            temp = temp.next
    
    def make_empty(self):
        self.head = None
        self.tail = None
        self.length = 0
        
    def append(self, value):
        new_node = Node(value)
        if self.head is None:
            self.head = new_node
            self.tail = new_node
        else:
            self.tail.next = new_node
            self.tail = new_node
        self.length += 1




my_linked_list = LinkedList(1)
my_linked_list.make_empty()

my_linked_list.append(1)
my_linked_list.append(2)

print('Head:', my_linked_list.head.value)
print('Tail:', my_linked_list.tail.value)
print('Length:', my_linked_list.length, '\n')

print('Linked List:')
my_linked_list.print_list()


"""
    EXPECTED OUTPUT:
    ----------------
    Head: 1
    Tail: 2
    Length: 2 

    Linked List:
    1
    2
    
"""

The provided Python code defines a simple linked list implementation with some basic functionalities. Let’s discuss each part of the code:

Class Definitions

1. Node Class: This class represents a single node in the linked list. Each node has a value and a next pointer, initially set to None.
2. LinkedList Class: This class represents the linked list itself. It has three attributes: head, tail, and length.
   • Constructor (__init__): When a new LinkedList is created, it takes an initial value, creates a new node with this value, and sets both the head and tail to this node. The length is initialized to 1.
   • print_list Method: This method prints all the values in the linked list from the head to the tail.
   • make_empty Method: This method empties the linked list by setting the head and tail to None and resetting the length to 0.
   • append Method: This method adds a new node with the given value to the end of the linked list. If the list is empty (i.e., the head is None), it sets both the head and tail to the new node. Otherwise, it links the current tail to the new node and updates the tail. The length of the list is incremented by 1.

Code Execution

• Initially, a LinkedList object (my_linked_list) is created with the value 1. So, the list starts with one node containing the value 1.
• The make_empty method is then called, which empties the linked list.
• Two append calls are made, adding the values 1 and 2 to the list.
• The final print statements display the values of the head, tail, and length of the list, as well as all the values in the linked list.

Expected Output

Based on the code’s logic, the expected output is correct:

Head: 1
Tail: 2
Length: 2 

Linked List:
1
2

This output reflects that after creating the linked list, emptying it, and then appending two values, the list contains two nodes with values 1 and 2, where 1 is the head and 2 is the tail of the list.

Summary

Article Name

A simple linked list implementation with some basic functionalities

Description

Explore the fundamentals of Python data structures with our guide to simple linked list implementation. This article delves into each aspect of linked list construction, from node creation to list manipulation methods like append and make_empty. Ideal for both beginners and seasoned programmers, this piece offers a clear understanding of basic linked list operations in Python, accompanied by practical code examples and explanations.

Author

techtinkerlabs

Publisher Name

TechTinkerLabs Media