Skip to content

Courses
Tutorials
Practice
Contests

Python Tutorial
Interview Questions
Python Quiz
Python Glossary
Python Projects
Practice Python
Data Science With Python
Python Web Dev
DSA with Python
Python OOPs

Python | Check if list is Matrix

Check if a List is Sorted or not – Python

Last Updated : 14 Apr, 2025

Comments

Improve

Suggest changes

Like Article

Like

Report

We are given a list of numbers and our task is to check whether the list is sorted in increasing or decreasing order. For example, if the input is [1, 2, 3, 4], the output should be True, but for [3, 1, 2], it should be False.

Using all()

all() function checks if every pair of consecutive elements in the list is in non-decreasing order.

Python

a = [1, 2, 3, 4, 5]  # For checking ascending order print(all(a[i] <= a[i + 1] for i in range(len(a) - 1)))  b = [5, 4, 3, 2, 1]  # For checking descending order print(all(b[i] >= b[i + 1] for i in range(len(b) - 1)))

Output

True True

Explanation:

For the list a = [1, 2, 3, 4, 5], we are checking for ascending order and here all() method is used verify if each element is less than or equals to its next element in the list. It only returns True if the list is sorted in ascending order.
For the list b = [5, 4, 3, 2, 1], we are checking descending order all() method verify if each element is greater than or equals to its next element in the list. It returns True if the list is sorted in descending order.

Note: To check for strictly increasing or decreasing sequences remove the equals sign (=) from the comparison.

Using sorted()

sorted() function returns a sorted version of the list. If the original list is equal to its sorted version it means the list is already sorted.

Python

a = [1, 2, 3, 4, 5] b = [5, 4, 3, 2, 1]  # Here, sorted(), sort list in ascending order print(a == sorted(a))   print(b == sorted(b))

Output

True False

Explanation:

sorted(a) returns a new sorted list.
a == sorted(a) compares the original list with its sorted version. If they match, the list is sorted.

Note: We can also use list.sort() method as well. To do this, we’ll create a copy of the original list, sort the copy and then compare the two lists.

Using for Loop

We can iterate through the list and check if each element is less than or equal to the next one, if the loop executes completely that means the list is sorted but if we break out of the loop that means the list is not sorted.

Python

a = [1, 2, 3, 4] res = True  for i in range(len(a) - 1):     if a[i] > a[i + 1]:         res = False         break  print(res)

Output

True

Explanation:

Iterates through the list and checks if each element is greater than the next one.
If any element is greater than the next, res is set to False and we break the loop.

Related Articles:
Check for Descending Sorted List
Sort List of Lists Ascending and then Descending
Difference between sorted() and sort()

Python | Check if list is Matrix

manjeet_04

Improve

Article Tags :

Python
Python list-programs
python-list

Practice Tags :

python
python-list

Similar Reads

Check if a list is empty or not in Python

In article we will explore the different ways to check if a list is empty with simple examples. The simplest way to check if a list is empty is by using Python's not operator. Using not operatorThe not operator is the simplest way to see if a list is empty. It returns True if the list is empty and F

Python | Check if list is Matrix

Sometimes, while working with Python lists, we can have a problem in which we need to check for a Matrix. This type of problem can have a possible application in Data Science domain due to extensive usage of Matrix. Let's discuss a technique and shorthand which can be used to perform this task.Metho

Check for True or False in Python

Python has built-in data types True and False. These boolean values are used to represent truth and false in logical operations, conditional statements, and expressions. In this article, we will see how we can check the value of an expression in Python. Common Ways to Check for True or FalsePython p

How to check if an object is iterable in Python?

In simple words, any object that could be looped over is iterable. For instance, a list object is iterable and so is an str object. The list numbers and string names are iterables because we are able to loop over them (using a for-loop in this case). In this article, we are going to see how to check

Check if two lists are identical in Python

Our task is to check if two lists are identical or not. By "identical", we mean that the lists contain the same elements in the same order. The simplest way to check if two lists are identical using the equality operator (==). Using Equality Operator (==)The easiest way to check if two lists are ide

Python - Sort list of list by specified index

When working with a list of lists, we often need to sort the inner lists based on the values at a specific index. Sorting by a specified index is useful in the custom ordering of multidimensional data. In this article, we will explore different ways to sort a list of lists by a specified index in Py

Python sorted containers | An Introduction

Sorted Containers is a powerful Python library that provides fast and easy-to-use implementations of SortedList, SortedDict and SortedSet data types. Unlike Pythonâ€™s built-in types, these containers maintain their elements in sorted order automatically as elements are added or removed. To use this l

Python | sort list of tuple based on sum

Given, a list of tuple, the task is to sort the list of tuples based on the sum of elements in the tuple. Examples: Input: [(4, 5), (2, 3), (6, 7), (2, 8)] Output: [(2, 3), (4, 5), (2, 8), (6, 7)] Input: [(3, 4), (7, 8), (6, 5)] Output: [(3, 4), (6, 5), (7, 8)] # Method 1: Using bubble sort Using th

Python - Returning index of a sorted list

We are given a list we need to return the index of a element in a sorted list. For example, we are having a list li = [1, 2, 4, 5, 6] we need to find the index of element 4 so that it should return the index which is 2 in this case. Using bisect_left from bisect modulebisect_left() function from bis

Creating a Sorted Merged List of Two Unsorted Lists in Python

Creating a sorted merged list of two unsorted lists involves combining the elements of both lists and sorting the resulting list in ascending order. For example: If we have list1 = [25, 18, 9] and list2 = [45, 3, 32] the output will be [3, 9, 18, 25, 32, 45]. Using + OperatorThis method merges the t

Corporate & Communications Address:

A-143, 7th Floor, Sovereign Corporate Tower, Sector- 136, Noida, Uttar Pradesh (201305)

Registered Address:

K 061, Tower K, Gulshan Vivante Apartment, Sector 137, Noida, Gautam Buddh Nagar, Uttar Pradesh, 201305

Advertise with us

Company
About Us
Legal
Privacy Policy
In Media
Contact Us
Advertise with us
GFG Corporate Solution
Placement Training Program

Languages
Python
Java
C++
PHP
GoLang
SQL
R Language
Android Tutorial
Tutorials Archive

DSA
Data Structures
Algorithms
DSA for Beginners
Basic DSA Problems
DSA Roadmap
Top 100 DSA Interview Problems
DSA Roadmap by Sandeep Jain
All Cheat Sheets

Data Science & ML
Data Science With Python
Data Science For Beginner
Machine Learning
ML Maths
Data Visualisation
Pandas
NumPy
NLP
Deep Learning

Web Technologies
HTML
CSS
JavaScript
TypeScript
ReactJS
NextJS
Bootstrap
Web Design

Python Tutorial
Python Programming Examples
Python Projects
Python Tkinter
Python Web Scraping
OpenCV Tutorial
Python Interview Question
Django

Computer Science
Operating Systems
Computer Network
Database Management System
Software Engineering
Digital Logic Design
Engineering Maths
Software Development
Software Testing

DevOps
Git
Linux
AWS
Docker
Kubernetes
Azure
GCP
DevOps Roadmap

System Design
High Level Design
Low Level Design
UML Diagrams
Interview Guide
Design Patterns
OOAD
System Design Bootcamp
Interview Questions

Inteview Preparation
Competitive Programming
Top DS or Algo for CP
Company-Wise Recruitment Process
Company-Wise Preparation
Aptitude Preparation
Puzzles

School Subjects
Mathematics
Physics
Chemistry
Biology
Social Science
English Grammar
Commerce
World GK

GeeksforGeeks Videos
DSA
Python
Java
C++
Web Development
Data Science
CS Subjects

@GeeksforGeeks, Sanchhaya Education Private Limited, All rights reserved

We use cookies to ensure you have the best browsing experience on our website. By using our site, you acknowledge that you have read and understood our Cookie Policy & Privacy Policy

Improvement

Suggest Changes

Help us improve. Share your suggestions to enhance the article. Contribute your expertise and make a difference in the GeeksforGeeks portal.

geeksforgeeks-suggest-icon

Create Improvement

Enhance the article with your expertise. Contribute to the GeeksforGeeks community and help create better learning resources for all.

geeksforgeeks-improvement-icon

Suggest Changes

min 4 words, max Words Limit:1000

Thank You!

Your suggestions are valuable to us.

What kind of Experience do you want to share?

Interview Experiences

Admission Experiences

Career Journeys

Work Experiences

Campus Experiences

Competitive Exam Experiences