input: Write a python function to classify a list as containing only even numbers, only odd numbers, or both.
  assert classifyList([2, 4, 6]) == "list contains only even numbers"
  assert classifyList([1, 3, 5]) == "list contains only odd numbers"
  assert classifyList([2, 3, 4, 5]) == "list contains both even and odd numbers"
  assert classifyList([]) == "list contains both even and odd numbers"
output: def classifyList(lst):
      has_even = any(x % 2 == 0 for x in lst)
      has_odd = any(x % 2 != 0 for x in lst)
      
      if has_even and has_odd:
          return "list contains both even and odd numbers"
      elif has_even:
          return "list contains only even numbers"
      elif has_odd:
          return "list contains only odd numbers"
      else:
          return "list contains both even and odd numbers"