(Python): How to Convert String to Integer using While Loop and then find the sum?

Question

So, I was able to make a program that adds the sum of a string of numbers in a for loop. However, I can’t figure out how to do it for a while loop.

Here’s what I have for a for loop.

num_string = “2514”
sum= 0

for dig in num_string:
sum+=int(dig)
print(sum)

Here’s my while loop that I’m struggling on.

while num_string >= 0:
sum += int(dig)
print(sum)

I honestly have the worst Professor in the world, so I’m trying to figure this all out on my own. I’ve tried googling it and looking at his “examples,” but I either can’t find anything or it doesn’t make sense.

I’m terrible at Python, so explaining in layman’s terms would be helpful.

Answer 1

there is a solution to do it without loops in case you don't know

num = "1234"

num = [int(i) for i in list(num)]

total = sum(num)

print(total)

Answer 2

1. It's not recommended to use built-in functions (e.g. sum) as variable names as it can mess up with your code.

2. In this case, a "for" loop is better than a "while" loop, but if you must use it try this:

num_string = "2514"
total = 0

i = 0
while i<len(num_string):
total += int(num_string[i])
i += 1
print(total) # 12