Summing elements inside tuple of tuples with recursion

Question

So my problem is as follows:

I have a tuple with 1 or more tuples inside it and i want sum all the numbers inside the tuple. But something is missing because theres a case when u have a tuple with a tuple with elements inside, it doesnt even checks them.

For example:

def soma_els_atomicos(tup):
    if tup == ():
        return 0
    if isinstance(tup[0],int):
        return tup[0] + soma_els_atomicos(tup[1:])
    if isinstance(tup[0],tuple):
        return 0 + soma_els_atomicos(tup[1:])

Input:

>>>tup = (3, ((((((6, (7, ))), ), ), ), ), 2, 1)

Output:

>>>soma_els_atomicos(tup)
>>> 6

The output should be 19 but I can't seem to notice what's missing.

Answer 1

This part of your code has a logical error:

    if isinstance(tup[0],tuple):
        return 0 + soma_els_atomicos(tup[1:])

Supposing tup[0] is a tuple, then the recursive sum should equal the sum of the numbers in tup[0] plus the sum of the numbers in tup[1:] . Your code uses 0 instead of the sum of the numbers in tup[0] . You can fix it this way:

    if isinstance(tup[0],tuple):
        return soma_els_atomicos(tup[0]) + soma_els_atomicos(tup[1:])

Example:

>>> tup = (3, ((((((6, (7, ))), ), ), ), ), 2, 1)
>>> soma_els_atomicos(tup)
19

By the way, I would recommend writing your code with if / elif / elif instead of separate if statements, and use an else case to handle invalid input types (eg by raising TypeError ).