input: Write a function to extract the non-vowel words in a given sentence. If there are no non-vowel words, return an empty list. If the sentence is empty, return an empty list.
  assert extract_words("This machine learning project is challenging.")==['machine', 'learning', 'project', 'is', 'challenging.', 'rst']
  assert extract_words("The quick brown fox")==[]
  assert extract_words("Why don't students study and Happy birds sing?")==["Why", "students", "study", "Happy", "birds", "sing?"]
  assert extract_words("ALL CAPS TEST")==['ALL', 'CAPS', 'TEST']
  assert extract_words("")==[]
output: def extract_words(sentence):
      vowels = "aeiouAEIOU"
      words = sentence.split()
      non_vowel_words = [word for word in words if not any(char in vowels for char in word)]
      return non_vowel_words