I’ve got a current lab that I’m working on for my university course (intro to programming). My code is nearly complete, but bugs out on one input. The assignment is to determine whether or not the input year is a leap year or not. In order to be a leap year, the year must be divisible by 4 and if the year is a century year (1700, 1800, 1900, 2000) it must be divisible by 400. Here’s the code:
is_leap_year = False
input_year = int(input())
if (input_year % 4 == 0) and (input_year % 400 == 0):
print(input_year, "- leap year")
elif (input_year % 4 == 0):
print(input_year, "- leap year")
else:
print(input_year, "- not a leap year")
A couple of things, quickly:
Not looking for the answer as this is an assignment. Alternatively if somebody could just point me in the right direction that would be great.
is_leap_year = False was prewritten code. I’m honestly not entirely sure how to use it in this instance.
The issue that I’m getting is that when the year ‘1900’ is input, it prints “1900 - leap year” because of the input_year % 4 == 0 line, but if I remove that line, it won’t consider years like 2016 as leap years because they don’t meet the first conditional requirement.
For issue 3, that means you need another check before that point. Something that will handle the century year cases.
Issue 2 may depend on what your program is supposed to do. Is it supposed to print out the answer, or is it supposed to return to a caller? If you’re supposed to return, that may just be a default.
Hey again! So my code now works, but I’m wondering if it’s the most efficient code. I’m going to post the code that I’ve submitted below. If you can think of a way that I could have written this more efficiently, can you let me know so that I can learn for next time? Thanks!
is_leap_year = False
input_year = int(input())
if (input_year % 400 == 0):
if (input_year % 4 == 0):
print(input_year, "- leap year")
else:
print(input_year, "- not a leap year")
else:
if (input_year % 100 != 0) and (input_year % 4 == 0):
print(input_year, "- leap year")
else:
print(input_year, "- not a leap year")
It wouldn’t ever be false, good point. I probably should have reversed the statements. The purpose was to determine if a year had a 0 remainder for both dividing by 400 and by 4. This probably should have been written like if (input_year % 4 == 0) and (input_year % 400 == 0): instead.
The purpose of is_leap_year is so you can avoid repeating the print calls multiple times. Instead set the variable appropriately in your if/else blocks, then afterwards check the variable to decide what to print. This way your code afterwards would also be able to use the is-leap functionality, and you haven’t repeated yourself.
The variable was initialized to False as a default value. With that having been established, you just need to determine under what conditions we have a leap year. If those conditions exist, set the variable to True. Otherwise, leave the variable as is.
After you have followed that advice, the task is complete.
Thanks so much, Glenn. If it wouldn’t take too much time, would you mind showing me an example of how I could use the boolean operator to reduce the number of print lines?
# without boolean variable
ticket_number = int(input("What number is on your ticket?: "))
# determine prize status and output result
if ticket_number % 700 == 0:
print("Ding! You won a shelf of Python books!")
elif ticket_number % 18 == 0 and ticket_number % 12 != 0:
print("Ding! You won a shelf of Python books!")
else:
print("Bzzz! You won a free 5 minute Java course!")
Two print statements:
# with boolean variable
ticket_number = int(input("What number is on your ticket?: "))
won_good_prize = False
# determine prize status
if ticket_number % 700 == 0:
won_good_prize = True
elif ticket_number % 18 == 0 and ticket_number % 12 != 0:
won_good_prize = True
# output result
if won_good_prize:
print("Ding! You won a shelf of Python books!")
else:
print("Bzzz! You won a free 5 minute Java course!")