input: Write a function to extract the non-vowel words in a sentence. The function should take a sentence as input and return a list of words that do not contain any vowels.
  assert extract_words("This machine learning project is challenging.")==["This", "machine", "learning", "project", "is", "challenging."]
  assert extract_words("Hello world!")==["world!"]
  assert extract_words("Python code is fun.")==["Python", "code", "is", "fun."]
  assert extract_words("A quick brown fox jumps over the lazy dog.")==[]
  assert extract_words("")==[]
output: def extract_words(sentence):
      vowels = "aeiouAEIOU"
      return [word for word in sentence.split() if not any(char in vowels for char in word)]