input: Write a python function to sum all odd numbers in a given range.
  assert sum_oddnumbers(1, 10) == 25
  assert sum_oddnumbers(1, 20) == 100
  assert sum_oddnumbers(10, 30) == 200
output: def sum_oddnumbers(start, end):
      return sum(num for num in range(start, end + 1) if num % 2 != 0)