input: Write a function to calculate the sum of series 1 + ½ + ⅓ + ... + 1/n. The function should take an integer n as input and return the sum of the series up to the nth term. If n is 0, the function should return 0.
  assert seriesSum(5)==2.283333333333333
  assert seriesSum(0)==0
  assert seriesSum(1)==1.0
  assert seriesSum(10)==2.9289682539682538
output: def seriesSum(n):
      if n == 0:
          return 0
      return sum(1/i for i in range(1, n+1))