input: Write a function to extract the non-vowel words from a given sentence.
  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.")==['T', 'm', 'Ch', 'll', 'ng']
  assert extract_words("Hello world")==['H', 'll', 'w', 'rld']
  assert extract_words("Python is fun")==['Pythn']
  assert extract_words("AI in 2023")==['','n','','']
  assert extract_words("")==[]
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