How To Create a Linked List in Python

A Python-linked list is a data type that represents a linear collection of data organized as nodes that link to other nodes. Using this simple guide, you can create your own.

A linked list is an abstract data type that functions as a linear collection of data elements organized as a collection of nodes, each of which contains information about what it contains and a link to another node. This can take two different forms: It can be either a singly linked list with only one direction of links between nodes or a doubly linked list with links to both the next and last item in the list. The advantage of this over a traditional array or list is that elements can be easily added and removed without changing the index of all other items. Because the data does not need to be stored consecutively, the memory used to store the linked list does not need to be reorganized.  However, unlike an array, you cannot access items in constant time (O(1)) because looking up an item in the list has a linear time complexity (O(n).

You might want to read this blog on data structures in Python.

What Is A Linked List In Python?

A Python-linked list is an abstract Python data type that allows users to organize information in nodes that then link to another node in the list. This allows you to insert and remove data without changing the index of other items in the list.

How to Make a Python Linked List?

With this in mind, we can consider implementing linked lists in a Python data structure. The following are some of the most common methods associated with this:

insert(): Insert an item at the top of the linked list.

find(): Locates an item in a linked list.

remove(): Removes a specified item with a specified value.

is empty() determines whether or not the linked list is empty.

get count(): Returns the number of linked list items.

Interestingly, there is no natural data structure in Python on which we can base this linked list. We can use the list data structure already built into Python to create a queue and a stack. However, before implementing a linked list, we must first create a node class.

This is due to the fact that each item in the linked list is a separate object that can contain any information it desires while also identifying the next item in the linked list. It must have an attribute pointing to or identifying the information it contains and an attribute pointing to the next node in the linked list. We must also add behaviors that allow us to extract the data from this node and the next node and the ability to set or adjust these attributes.

We have val and next attributes corresponding to the node’s data while pointing to the next node in the linked list. The fact that we initially set it next to None indicates that we created one with no given next node. We then add methods that allow us to print both the current val and the next node, change the val and set the next node.

With this in mind, we can proceed to construct the linked list. As shown in the node implementation above, we will focus on a singly linked list, meaning that each node only has a link to the next node in the linked list.

I hope you got a quick overview of the python linked list and how to create one. If you are passionate about learning more about python and other technologies, check out the data structures and system design course, by Learnbay and learn directly from the experts.