Problem with iterables (Sum and for loops)

Question

So I am trying to write a code to find out the if a number is divisible by 3. The steps go like this, enter number, add all digits, if digits greater than 10 add digits together until below 10, see if the digit remaining is 3, 6 or 9 and then print out if it is divisible by 3 or not. Here is my code so far:

user_input = int(input('Enter number: '))
sum = 0
for num in user_input:
    sum += int(num)

    if sum > 10:
        while sum > 10:
            sum = 0
            for num in user_input:
                sum += int(num)

            if sum == 3 or 6 or 9:
                print('Your number is divisble by 3')

            else:
                print('Your number is not divisible by 3')

    else:

        if sum == 3 or 6 or 9:
            print('Your number is divisble by 3')

        else:
            print('Your number is not divisible by 3')

Anyone know how to fix the bug?

`if sum > 10:` should be outside your for loop that counts the sum — OneCricketeer, Jan 26 '20 at 08:26
Why do you need to sum a number to check divisible by 3? `int(user_input) % 3 == 0` is the most common way to do that — OneCricketeer, Jan 26 '20 at 08:29
I am trying to find a different way to find a number that's divisible by 3 thanks — Tigre, Jan 26 '20 at 08:32
Okay... If the very last digit is 3,6,9... `user_input[-1] in {'3' ,'6' ,'9' }` and some rule about units of 10 that I forgot — OneCricketeer, Jan 26 '20 at 08:33
If you want to sum numbers, I can advise you to focus on making a function to do exactly that. Then, never indent code unless it uses variables from the if statement or loop — OneCricketeer, Jan 26 '20 at 08:36
It's a different way I am learning to find the divisibility rule for 3 — Tigre, Jan 26 '20 at 08:39
The problem is that it says | for num in user_input: TypeError: 'int' object is not iterable — Tigre, Jan 26 '20 at 08:43

Grzegorz Skibinski · Answer 1 · 2020-01-26T08:56:48.257

1

Replace every:

if sum == 3 or 6 or 9:

With

if (sum in ( 3, 6, 9)):

Also - don't overridesum - it's default function in python, you can name your variable like _sum for instance.

Edit:

IIUC, this is what you're trying to do (you insert multiple numbers delimited by white space initially):

user_input = input('Enter numbers: ').split(" ")

for num1 in user_input:
    sum1 = int(num1)
    if sum1 > 10:
        while sum1 > 10:
            sum_=sum1
            sum1=0
            for num in str(sum_):
                sum1 += int(num)
        if sum1 in (3, 6, 9):
            print(num1, ': Your number is divisble by 3')
        else:
            print(num1, ': Your number is not divisible by 3')

To just get and process single number:

user_input = input('Enter number: ')

sum1 = num1 = int(user_input)

if sum1 > 10:
    while sum1 > 10:
        sum_=sum1
        sum1=0
        for num in str(sum_):
            sum1 += int(num)
    if sum1 in (3, 6, 9):
        print(num1, ': Your number is divisble by 3')
    else:
        print(num1, ': Your number is not divisible by 3')

edited Jan 26 '20 at 08:56

answered Jan 26 '20 at 08:26

Grzegorz Skibinski

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sorry but that's not the problem it happens on line 3 – Tigre Jan 26 '20 at 08:27
@Fort it's one of the problems. Indentation is the other – OneCricketeer Jan 26 '20 at 08:28
Ah, right for line 3 just don't convert user input to ```int``` in line 2 it will iteratate over all characters - digits - then. – Grzegorz Skibinski Jan 26 '20 at 08:31
can you help me with that please thanks – Tigre Jan 26 '20 at 08:31
Why you're putting surrounding parenthesis, why not just `if sum in (3, 6, 9):`? – funnydman Jan 26 '20 at 08:37
For readability, but you're right it's redundant – Grzegorz Skibinski Jan 26 '20 at 08:45

Problem with iterables (Sum and for loops)

1 Answers1