input: from typing import List
  
  def count_vowels(string: str) -> int: 
      vowels = "aeiou"
      count = 0
      for s in string:
          if s.lower() in vowels:
              count += 1
      return count
  
  """
  >>> count_vowels("Hello World")
  3
  >>> count_vowels("Python Programming")
  4
  """
output:     vowels = "aeiou"
      count = 0
      for s in string:
          if s.lower() in vowels:
              count += 1
      return count