input: def extract_words(sentence: str) -> list:
      """
      Extracts the non-vowel words from a given sentence.
      
      >>> extract_words("This machine learning project is challenging.")
      ['T', 'h', 's', 'm', 'ch', 'n', 'l rn ng', 'pr j ct', 's', 'ch lng g s']
      >>> extract_words("Hello World!")
      ['H', 'W', 'r ld']
      """
output:     vowels = "aeiouAEIOU"
      words = sentence.split()
      result = []
      for word in words:
          non_vowel_word = ''.join([char for char in word if char not in vowels])
          result.append(non_vowel_word)
      return result