Will anybody please edit this code so it starts returning sum of values for ex-42 output-6

Question

n = int(input())
length = 0
while n > 0:
n //= 10
length += 1

print(length)

Answer 1

#Try this
n = int(input())
a = 0
length = 0
while n > 0:
b= n%10
a+= b
n//= 10
length += 1
print(a)

Answer 2

If you're asking to get the sum of the digits in a given number.
I.E. input is 42
4 + 2 = 6
output 6
Then here:

nums = map(int, list(input()))
total = 0

for num in nums:
total += num

print(total)

Otherwise, please explain a bit better what it is you're trying to do.