input: Write a python function to filter odd numbers from a given list.
  assert filter_oddnumbers([1, 2, 3, 4, 5, 6, 7, 8]) == [1, 3, 5, 7]
  assert filter_oddnumbers([10, 15, 20, 25, 30]) == [15, 25]
  assert filter_oddnumbers([2, 4, 6, 8, 10]) == []
output: def filter_oddnumbers(lst):
      return [num for num in lst if num % 2 != 0]