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(7) == 2.5928571428571425
assert harmonic_sum(4) == 2.083333333333333
assert harmonic_sum(19) == 3.547739657143682


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

Test 248 of 974: 177/248 (71.37096774193549%): failed