Python Program to Create and Display Linked List

«
»

This is a Python program to create a linked list and display its elements.

Problem Description

The program creates a linked list using data items input from the user and displays it.

Problem Solution

1. Create a class Node with instance variables data and next.
2. Create a class LinkedList with instance variables head and last_node.
3. The variable head points to the first element in the linked list while last_node points to the last.
4. Define methods append and display inside the class LinkedList to append data and display the linked list respectively.
5. Create an instance of LinkedList, append data to it and display the list.

Program/Source Code

Here is the source code of a Python program to create a linked list and display its elements. The program output is shown below.

class Node:
    def __init__(self, data):
       self.data = data
       self.next = None
 
class LinkedList:
    def __init__(self):
        self.head = None
        self.last_node = None
 
    def append(self, data):
        if self.last_node is None:
            self.head = Node(data)
            self.last_node = self.head
        else:
            self.last_node.next = Node(data)
            self.last_node = self.last_node.next
 
    def display(self):
        current = self.head
        while current is not None:
            print(current.data, end = ' ')
            current = current.next
 
a_llist = LinkedList()
n = int(input('How many elements would you like to add? '))
for i in range(n):
    data = int(input('Enter data item: '))
    a_llist.append(data)
print('The linked list: ', end = '')
a_llist.display()
Program Explanation

1. An instance of LinkedList is created.
2. The user is asked for the number of elements they would like to add. This is stored in n.
3. Using a loop, data from the user is appended to the linked list n times.
4. The linked list is displayed.

advertisement
advertisement
Runtime Test Cases
Case 1:
How many elements would you like to add? 5
Enter data item: 3
Enter data item: -2
Enter data item: 1
Enter data item: 5
Enter data item: 0
The linked list: 3 -2 1 5 0 
 
Case 2:
How many elements would you like to add? 1
Enter data item: 6
The linked list: 6 
 
Case 3:
How many elements would you like to add? 4
Enter data item: 2
Enter data item: 9
Enter data item: 3
Enter data item: 2
The linked list: 2 9 3 2

Sanfoundry Global Education & Learning Series – Python Programs.

To practice all Python programs, here is complete set of 150+ Python Problems and Solutions.

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & technical discussions at Telegram SanfoundryClasses.