How to Check Leap Year in Python?

Garvit Parakh | September 20, 2021 | Python examples | No Comments

In this Python example, we will discuss different ways by which we can check that the given year is a leap year or not. Let’s begin.

Table of Contents

1. What is a Leap Year ?

A leap year or bissextile year is a calendar year that contains an additional day added to keep the calendar year synchronized with the astronomical year or seasonal year.
– Wikipedia

In order to correct and coordinate the world’s system of dating and the solar system’s physical properties, we insert an additional day after a cycle of some years.

Instead of 365 days, each leap year has 366 days, generally, we extend days in February from 28 days to 29 days. These extra days occur in each year which is an integer multiple of 4.

Example:

Input :  2020
Output : 2020 is a Leap Year

Input : 2011
Output : 2011 is not a Leap Year

Some of the topics which will be helpful for understanding the program implementation better are:

2. Python Program to Check if a Given Year is Leap Year or Not

The year is a leap year if any of the following conditions are satisfied:

The year is multiple of 400.
The year is multiple of 4 and not multiple of 100.

Let’s implement the code and see how it works.

# Python program to check leap year or not
year = int(input("Enter the year: "))

if (year % 4) == 0:
  if (year % 100) == 0:
    if (year % 400) == 0:
      print(year,"is a leap year")
    else:
      print(year,"is not a leap year")
  else:
    print(year,"is a leap year")
else:
  print(year,"is not a leap year")

Output
Enter the year: 2000
2000 is a leap year

First, we check if the given year is divisible by 4, then if it is divisible by 100 then by 400.

If it is not divisible by 4, then it’s confirmed that it is not a leap year. If it is divisible by 4 but not 100 then it is a leap year. If it is divisible by 4, 100, and 400 then it is a leap year.

#Python Program to Check leap year
n = int(input("Enter the number to check if it is Prime or not: "))
if n > 1:
  for i in range(2, int(n/2)+1):     
    if n % i == 0:
      print(n, "is not a prime number")
      break
  
  else:
    print(n, "is a prime number")
 
else:
  print(n, "is not a prime number")

3. Check for a Leap Year Using Function

Let’s implement the code by defining a function

#Python Program to Check leap year using Function
def checkleap(year): 
  return (((year % 4 == 0) and (year % 100 != 0)) or (year % 400 == 0));


year = 2016
if checkleap(year):
  print(year,"is a Leap Year")
else:
  print(year," is Not a Leap Year")

Inside the checkleap function, we have given the condition to check in a single line.

4. Check for a Leap Year Using Module

In Python, we have calendar module which has a method isleap inside it. The isleap method return True, if the year passed as a parameter is a leap year and False when it is not.

Let’s see how it works

import calendar
year = 2010
if calendar.isleap(year):
  print("Leap Year")
else:
  print("Not a Leap Year")

Output
Not a Leap Year

5. Conclusion

In this article, we have learned different ways by which we can check if a given year is a leap year or not. We have covered the basic method to check leap year, checked leap year by defining a function, giving the condition in a single line, and also checked using the calendar module.

Helpful Links

Please follow the Python tutorial series or the menu in the sidebar for the complete tutorial series.

Also for examples in Python and practice please refer to Python Examples.

Complete code samples are present on Github project.

Recommended Books

An investment in knowledge always pays the best interest. I hope you like the tutorial. Do come back for more because learning paves way for a better understanding

Codingeek