leap year problem

leap_year.py

def leap_year(y):
    if y % 400 == 0:
        return True
    if y % 100 == 0:      
        return False 
    if y % 4 == 0:
        return True 
    return False

# or
def leap_year(y):
    return y % 400 == 0 or (y % 100 != 0 and y % 4 == 0)

def report_leap_year(y):
    if leap_year(y):
        print("{0} is a leap year".format(y))
    else:
        print("{0} is not a leap year".format(y))

report_leap_year(2000) # => 2000 is a leap year
report_leap_year(1900) # => 1900 is not a leap year
report_leap_year(2012) # => 2012 is a leap year
report_leap_year(2013) # => 2013 is not a leap year