Question: 
Write a function to calculate the harmonic sum of n-1.


Model's Code:
def harmonic_sum(n):
    return sum(1/i for i in range(1, n))



Sample Correct Code:
def harmonic_sum(n):
  if n < 2:
    return 1
  else:
    return 1 / n + (harmonic_sum(n - 1))


Asserts:
assert harmonic_sum(10)==2.9289682539682538
assert harmonic_sum(4)==2.083333333333333
assert harmonic_sum(7)==2.5928571428571425 


Tests:
Test 1 of 3: FAIL: AssertionError()

Test 704 of 974: 531/704 (75.42613636363636%): failed