input: Write a function to extract non-vowel words from a given sentence. Return a list of words that do not contain any vowels.
  def extract_words(sentence):
      non_vowel_words = []
      words = sentence.split()
      vowels = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U']
      for word in words:
          if not any(char in vowels for char in word):
              non_vowel_words.append(word)
      return non_vowel_words
  
  assert extract_words("This machine learning project is challenging.") == ['This', 'machine', 'learning', 'project', 'is', 'challenging.']
  assert extract_words("Python is fun") == ['Python', 'fun']
  assert extract_words("The quick brown fox jumps over the lazy dog") == []
  assert extract_words("") == []
  assert extract_words("Rhythm") == ['Rhythm']
output: def extract_words(sentence):
      non_vowel_words = []
      words = sentence.split()
      vowels = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U']
      for word in words:
          if not any(char in vowels for char in word):
              non_vowel_words.append(word)
      return non_vowel_words