# Leap Year in Python

## What is a Leap Year ?

Contents

A leap year occurs every four years to ensure that the calendar year aligns with the astronomical year. Normally, a year has 365 days, but the Earth’s orbit around the sun takes approximately 365.2422 days. To account for this extra fraction of a day, an additional day is added to the calendar every four years.

## Leap Year Program in Python

Python, being a versatile programming language, provides us with an easy way to identify leap years. Let’s explore a simple algorithm to determine whether a given year is a leap year:

``````def is_leap_year(year):
if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0):
return True
else:
return False

print(is_leap_year(2000))  # Output: True (divisible by 400)
print(is_leap_year(2020))  # Output: True (divisible by 4 but not by 100)
print(is_leap_year(1900))  # Output: False (divisible by 100 but not by 400)
print(is_leap_year(2023))  # Output: False (not divisible by 4)
``````

## Leap Year by Using Python’s Calendar Module

Python’s `calendar` module simplifies leap year identification through its built-in functions. The `isleap() `function within the module can determine whether a given year is a leap year or not.

Here’s how we can use the isleap() function

``````import calendar

def is_leap_year(year):
return calendar.isleap(year)

print(is_leap_year(2000))  # Output: True (divisible by 400)
print(is_leap_year(2020))  # Output: True (divisible by 4 but not by 100)
print(is_leap_year(1900))  # Output: False (divisible by 100 but not by 400)
print(is_leap_year(2023))  # Output: False (not divisible by 4)
``````