input: 
  def remove_vowels(string: str) -> str:
      """ Remove all vowels from a given string.
      >>> remove_vowels("Hello, World!")
      'Hll, Wrld!'
      >>> remove_vowels("Python Programming")
      'Pythn Prgrmmng'
      """
      vowels = ['a', 'e', 'i', 'o', 'u']
      new_string = ''
      for char in string:
          if char.lower() not in vowels:
              new_string += char
      return new_string
  
output:     vowels = ['a', 'e', 'i', 'o', 'u']
      new_string = ''
      for char in string:
          if char.lower() not in vowels:
              new_string += char
      return new_string