Python: Check Leap Year

1. Introduction

A leap year occurs nearly every 4 years to adjust for the fact that Earth completes its orbit around the Sun in approximately 365.24 days. In a leap year, an extra day, February 29th, is added. To determine whether a year is a leap year or not, we follow certain rules. In this blog post, we will implement a Python program to check if a given year is a leap year.

2. Program Overview

1. Input a year from the user.

2. Check if the year is divisible by 4.

3. However, years divisible by 100 are not leap years unless they are also divisible by 400.

4. Display the result.

3. Code Program

# Python program to check if a year is a leap year

# Function to check leap year
def is_leap_year(year):
    """Check if a year is a leap year."""
    if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0):
        return True
    return False

# Input the year
year = int(input("Enter a year: "))

# Check and display if the year is a leap year
if is_leap_year(year):
    print(f"{year} is a leap year.")
else:
    print(f"{year} is not a leap year.")

Output:

Enter a year: 2000
2000 is a leap year.

Enter a year: 1900
1900 is not a leap year.

4. Step By Step Explanation

1. We start with defining a function named is_leap_year. This function checks if a given year is divisible by 4 but not by 100, or if it's divisible by 400.

2. In the main part of the program, we collect the year from the user.

3. We then call our is_leap_year function to determine if the year is a leap year.

4. Finally, we display the result based on the function's return value.