def digit_sum(n):
    n = str(n)
    summ = 0
    for i in n:
        summ += int(i)
    print summ

digit_sum(234)

def digit_sum(n):
    n = str(n)
    summ = 0
    for i in n:
        summ += int(i)
    return summ

digit_sum(234)
print summ

print digit_sum(234)

a = digit_sum(234)
print a