In this snippet, we will learn how to check year is leap year or not in Python.

Determine if a year is a leap year

1. If a year is evenly divisible by 4 means having no remainder then go to the next step. If it is not divisible by 4. It is not a leap year. For example, 1997 is not a leap year.
2. If a year is divisible by 4, but not by 100. For example, 2012 is a leap year. If a year is divisible by both 4 and 100, go to the next step.
3. If a year is divisible by 100, but not by 400. For example, 1900 then it is not a leap year. If a year is divisible by both, then it is a leap year. So 2000 is a leap year.

Example 1

Using if else:

def checkLeapYear(year):
    if (year % 400 == 0) or (year % 100 != 0) and (year % 4 == 0):
        print("{0} year is a leap year".format(year))
    else:
        print("{0} year is not a leap year".format(year))

# input year from user
year = int(input("Enter a year: "))
checkLeapYear(year)

Example 2

Using calendar linbrary:

def checkLeapYear(year):
    # return true if year is a multiple
    # of 4 and not multiple of 100.
    # or year is multiple of 400.
    import calendar
    return (calendar.isleap(year))

# input year from user
year = int(input("Enter a year: "))
if (checkLeapYear(year)):
    print("{0} year is a leap year".format(year))
else:
    print("{0} year is not a leap year".format(year))