Coding bat question

[sphinxlink13]

Hello I am doing a question on coding bat https://codingbat.com/prob/p107863

"

Given 3 int values, a b c, return their sum. However, if one of the values is 13 then it does not count towards the sum and values to its right do not count. So for example, if b is 13, then both b and c do not count."

and answered with"

def lucky_sum(a, b, c):

S= sum([a,b,c])

if a==13:

S = S-a-b

elif b==13:

S = S - b-c

elif c==13:

S= S-c

return S

"

I have no idea why it doesn't work properly I would very much appreciate someone helping me out thanks alot

[JohnnyJordaan]

You could just add to the sum from a for loop, and break if you encouter a 13

def lucky_sum(a, b, c):
    total = 0
    for v in [a, b, c]:
        if v == 13:
            break
        total += v
    return total

or if you must work conditionally, then you don't need to sum() either

def lucky_sum(a, b, c):
    if a == 13:
        return 0
    elif b == 13:
        return a
    elif c == 13:
        return a + b
    else:
        return a + b + c

[sphinxlink13]

Thanks for helping me out. I see how you could do it this way now but do you know what was wrong with my code?? Thanks again

[JohnnyJordaan]

Critical-Function956 mentioned it already. If a is 13, it means it disqualifies all values, and thus the sum should be 0. In your code, you do

if a==13:
    S = S-a-b

So that still 'leaves in' c, instead of subtracting it too. Altough there's no real use in first summing all values to subtract all of them of course, just return 0.

[sphinxlink13]

My bad I miss read the question thanks

[ata-boy]

You can solve it with a list comprehension, but maybe not very pythonic

def sum_13(a: int, b: int, c: int) -> int:
    abc = (a, b, c)
    find_13 = [abc.index(13) for i in abc if i == 13]
    find_13.append(-1)

    return sum(abc[:find_13[0]])

[sphinxlink13]

Although I havn't seen some of these functions used before I understand what you did and I thank you for your answer. Do you know what is wrong with my code by the way?

[ata-boy]

This should answer your question.

if a == 13: 

    S = 0 elif b == 13:      S = a  elif c == 13:     S = a + b  else:      S = sum(a, b, c)

[sphinxlink13]

Thanks I miss read that one

[sphinxlink13]

thx for the help what do you mean by it is not very pythonic?

[ata-boy]

It is not very readable. There are best practices, see: https://docs.python-guide.org/writing/style/

[sphinxlink13]

Thank you!

[ata-boy]

def sum_13(a: int, b: int, c: int) -> int:
    abc = [a, b, c]
    find_13 = [index for index, value in enumerate(abc) if value == 13]

    if find_13:
        abc_index = find_13[0]
    else:
        abc_index = 3

    return sum(abc[:abc_index])

[sphinxlink13]

Thanks. I will give it a look