input: def remove_vowels(string: str) -> str:
      """
      This function removes all vowels from the given string.
      >>> remove_vowels("Hello, World!")
      'Hll, Wrld!'
      >>> remove_vowels("Python programming is fun")
      'Pythn prgrmmng s fn'
      >>> remove_vowels("AEIOUaeiou")
      ''
      """
output:     vowels = "aeiouAEIOU"
      return ''.join([char for char in string if char not in vowels])