input: def filter_vowels(string: str) -> str:
      """
      Filter out all the vowels from a given string and return the modified string.
  
      >>> filter_vowels('hello world')
      'hll wrld'
      >>> filter_vowels('Python Programming')
      'Pythn Prgrmmng'
      """
      vowels = ('a', 'e', 'i', 'o', 'u')
      return ''.join(c for c in string if c not in vowels)
output:     vowels = ('a', 'e', 'i', 'o', 'u')
      return ''.join(c for c in string if c.lower() not in vowels)