So this was my code for the digit_sum part of the section and quite frankly, the section did give me a lot of issues of all the sections of Python. Even though I got the part right, I still need some help understanding them so I am going to ask you guys some questions.

```
def digit_sum(n):
total = 0
nstring = str(n)
for digit_sum in nstring:
total = total + int(digit_sum)
return total
print digit_sum (314)
```

We set our total to zero, why did we do that?

I know that the key to the whole problem was the "total = total + int(digit_sum)" part but I don't get how it is supposed to give us the sum of a number's digits. Can anyone please help explain to me how it would work in regards to adding up the digits of 314?