Learning Recursive functions and my return won't hit when criteria is met [duplicate]

Question

I'm working through an algorithm and wanted to try to use recursive functions to solve it. In doing so I have this code:

def persistence(n, count=0):
    holder = 1
    if n < 9:
        return count
    num = [int(a) for a in str(n)]
    print(f'num {num}')

    for i in num:
        holder = holder * i
        print(f'holder {holder}')

    count += 1
    print(f'count {count}')

    if holder < 9:
        print(f'The final count is {count}')
        return count
    else:
        persistence(holder, count)

    persistence(39)

The problem is the return in the If statement never gets called when the criteria is met:

    if holder < 9:
    print(f'The final count is {count}')
    return count
else:
    persistence(holder, count)

It will run the print but never run the return and instead recalls the functions until nothing is returned.

Answer 1

I think you just need to return the result of the recursive call in the final line of the function persistence():

def persistence(n, count=0):
    holder = 1
    if n < 9:
        return count
    num = [int(a) for a in str(n)]
    print(f'num {num}')

    for i in num:
        holder = holder * i
        print(f'holder {holder}')

    count += 1
    print(f'count {count}')

    if holder < 9:
        print(f'The final count is {count}')
        return count
    else:
        return persistence(holder, count)

persistence(39)

Output:

num [3, 9]
holder 3
holder 27
count 1
num [2, 7]
holder 2
holder 14
count 2
num [1, 4]
holder 1
holder 4
count 3
The final count is 3