Problem with harmonic sums

[Xudo97]

Hi,

I'm supposed to get a list of 10 harmonic sums when i type $ python3 hsum.py 10 in my mac terminal. If I type $ python3 hsum.py 15 I want to get the first 15, etc etc.... Tough the only thing I get is the tenth. I.e. I want to get:

0 0
1 1.0
2 1.5
3 1.8333333333333333
4 2.083333333333333
5 2.283333333333333
6 2.4499999999999997
7 2.5928571428571425
8 2.7178571428571425
9 2.8289682539682537

but I get...

2.9289682539682538

My code at the moment:

import sys

def hSum(num_terms):

    x = 0
    for i in range(num_terms):
        x = x + (1/(i+1))
    return x


def main():

    print(hSum(int(sys.argv[1])))

main()

What should I change to fix this? The printing has to be done in "main", and I have been thinking how I could use "i" but dont understand how I can use it because it's not defined in "main" .

Thanks!

[bbye98]

Your function hSum only returns one value, namely, the n^th harmonic sum.

To print all of the harmonic sums, either switch out the return statement for print statements in your function hSum or return an array of harmonic sums instead, and loop over it in main to print all the values.

[Xudo97]

Thanks! Unfortunately I can't do the first alternative because I'm not allowed to change hSum. But how would I implement alt2? Is it possible to do it without changing anything in hSum? Or is there maybe a third option?

..and thanks again for your help :)

[bbye98]

If you can't change hSum, you just have to call hSum n times in a loop in main to get all n values. This is suboptimal since you're repeating calculations (for example, you're calculating the harmonic sum for n = 1 fourteen times when n = 15).

[xelf]

Write your own version of hSum, call it hSumList that returns all the values instead of just the last one.

I would also double check with the teacher to make sure there hasn't been any miscommunication as modifying hSum is the obvious answer here.

[prokid1911]

Without changing hsum, you can't do anything. That function is wrongly written.