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1. Print Numbers 1–1002. Print Even Numbers in Range3. Print Odd Numbers in Range4. Sum of Digits5. Reverse Digits of a Number6. Calculate Factorial (Loop)7. Fibonacci Series8. Palindrome Number Check9. Count Digits in a Number10. GCD of Two Numbers (Loop)11. LCM of Two Numbers (Loop)12. Print Prime Numbers in Range13. Count Prime Numbers in Range14. Check Composite Number15. Power of 2 Checker16. Print Number Pattern17. Print Star Pattern18. Armstrong Numbers in Range19. Strong Numbers in Range20. Sum of Series 1/1 + 1/2 + … + 1/N21. Print Multiplication Series22. Print Pyramid Pattern23. Print Inverted Pyramid Pattern24. Print Floyd's Triangle25. Print Pascal's Triangle

Sum of Digits in Python

Compute the sum of digits of an integer using a loop.

BeginnerLoop ProgramsExample 4 of 25
sum-of-digits.py
1# Program to find the sum of digits of a number
2

3num = int(input("Enter an integer: "))
4

5total = 0
6temp = abs(num)
7

8while temp > 0:
9    digit = temp % 10
10    total += digit
11    temp //= 10
12

13print("Sum of digits of", num, "is", total)

Output

Enter an integer: 1234
Sum of digits of 1234 is 10

What's going on

We repeatedly extract the last digit with % 10, add it to a running total, and remove it using integer division // 10.

After this program

If the idea is still fuzzy, read Day 9: Loops and Iteration in the Python course. For a short check, try the Python quiz (300 questions). Stay with all 25 loop programs, or see every topic on Python exercises.

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