I wrote a simple recursive function to calculate the sum of digits of a number.
But instead of returning an integer, it prints None.
def digit_sum(n):
if n < 10:
return n
print(digit_sum(n // 10) + n % 10)
result = digit_sum(452)
print(result)
because print returns None. Also, this should be a proper Q&A, not a "best practices" discussion
You're printing the result of the recursive call, but you're not returning it. So when digit_sum(452) finishes, it returns None because there's no return statement in the recursive branch.
Your function returns None because you never return anything in the recursive case — you only print() the result. print() displays the value but does not return it. So the function implicitly returns None.
def digit_sum(n):
if n < 10:
return n
return digit_sum(n // 10) + n % 10
result = digit_sum(452)
print(result)
It's not because print() returns None, @DeepSpace! The result of print() is discarded.
