Given an integer, say 287591, we want to calculate the sum of all its digits. The result would be 32 = 2+8+7+5+9+1. This problem was already considered in the while-loop section (example 6). Now we are solving it with a for-loop.
How do we proceed with a for-loop? We change the integer into a string! Python allows us to iterate over the characters in the string and while doing so we add up “the digits.” Note that in the for-loop we need to convert the character “5” into digit 5 before making the addition.
# 02Loops example_11 SumDigits2.py
# add up the digits in an integer using a for loop
n = int(raw_input("Please input an integer:"))
sum = 0
for i in str(n): #Convert integer sum into a string
#Convert the string reresenting a single digit into an integer and add
sum = sum + int(i)
print(sum)
The following video uses this problem in a nested loop setting. Video Length: 4:33
