Calculate the harmonic sum of N - 1

Calculate the harmonic sum of N - 1.

Note:

The harmonic sum is the sum of reciprocals of the positive integers.

The reciprocal is the quantity obtained by dividing the number

one by a given quantity.

Example:

harmonic series

def harmonic_sum(N):
    if N < 2:
        return 1
    else:
        return 1 / N + (harmonic_sum(N - 1))

# test
print(harmonic_sum(7))     # 2.5928571428571425
print(harmonic_sum(4))     # 2.083333333333333

See also

https://www.w3resource.com/python-exercises/data-structures-and-algorithms/python-recursion-exercise-8.php