Because Python is rapidly evolving, there are many subjects that we need to understand that are extremely basic and that everyone should know. In this blog, we will explore what a linked list is in Python, how it works, and the functions that can be applied to it.

Many essential fundamentals should be learned as a student, such as data types, strings, arrays, sorting algorithms, tuples in Python, and so on. This tutorial will cover how to use a linked list in Python. Let’s start from the beginning.

What is the definition of a linked list?


In Python, a linked list is a linear data structure that stores data in contiguous memory locations rather than arrays of data items linked together. In Python, each node in a linked list has a data field and a reference to the linked list’s next node. In linked, each element is called a node, and pointers are used to connect them. The head of the linked list is the first node.


The size of the linked list is flexible. We can have an endless number of nodes unless the device has enough storage. There are two types of linked lists, which we’ll go over in this tutorial one by one.


In Python, a linked list is a node chain, with each node containing data and the address or reference to the next node. The head, which stores the reference to the first node, is the starting point of the linked list.


Python’s Head of the Linked List


The first architectural item of the linked list is the ‘head node,’ or top node in the list. The Head is set to None when the list is first generated because there are no nodes in it. (Note that the linked list does not always require a node to begin, and the head option will default to None if one is not provided.)




Python Singlely Linked List


In Python, a single pointer connects the next node in a singly linked list to the linked list’s next node. The data and pointer for each node in the linked list must be saved. The next pointer in the linked list’s last node is null, indicating that the linked list has reached its conclusion.


Some Characteristics of a Singlely Linked List








In a Python linked list, what is a node?


A linked list object with a data field and a pointer to another node is called a node. A node can be defined as the diagram below, which shows the node’s basic structure.


Python’s Doubly Linked List


A singly linked list or a linked list is easier to implement, but traversing it in reverse is far more complicated. To get around this, we can use a Doubly LinkedList, in which each node has two pointers: one to point to the previous node and one to point to the next node.


In a doubly-linked list in Python, iteration is more efficient, especially if you need to repeat in reverse, and deletion of specific nodes is more efficient.


To summarize, a doubly linked list is a more complex linked list in which each node contains a pointer to the preceding and subsequent nodes in the series. In a doubly-linked list, each node has node data, a pointer to the next node (next pointer), and a pointer to the previous node (previous pointer) (previous pointer).




Python features of a doubly linked list





Some of the linked list functions in Python




This insert method takes some information, turns it into a new node, and adds it to the list. Although you can put a node anywhere in the list, the easiest way is to put it at the top and point the new node at the old one (sort of pushing the other nodes down the line).






The size method is simple: it simply counts nodes till they run out, then returns the number of nodes found. The process starts at the top node and works its way down the line of nodes until it reaches the end (at which time the current will be None), keeping track of how many nodes it has passed through.






Instead of traversing the full list of nodes, search examines at each stop to see if the current node contains the necessary data, and if it does, it returns the node that contains that data. If the method searches the entire list and still cannot locate the data, it returns a value error and notifies the user that it is not in the list.






You’ll be happy to learn that delete and search are nearly identical! The delete function traverses the list in the same way as search does, but without keeping track of the current node. When the delete method gets to the node it wants to delete, it looks at the previous node it visited (the ‘prior’ node) and resets its pointer to the next node in line instead of the soon-to-be-deleted node. Because no nodes point to the unfortunate node that is being removed, it is effectively removed from the list!




Consider some significant distinctions.


The following is the difference between a singly linked list and a circular singly linked list:





The difference between a doubly-linked list and a circular doubly-linked list is.