input: Write a function to extract the non-vowel words from a given sentence. If the given sentence is empty then return an empty list.
  assert extract_words("This machine learning project is challenging")==['This', 'machine', 'learning', 'project', 'is', 'challenging']
  assert extract_words("The quick brown fox jumps over the lazy dog")==['The', 'quick', 'brown', 'fox', 'jumps', 'over', 'the', 'lazy', 'dog']
  assert extract_words("Python programming is fun")==['Python', 'programming', 'is', 'fun']
  assert extract_words("What a nice day")==['Wht', 'nc', 'dy']
  assert extract_words("")==[]
output: def extract_words(sentence):
      if not sentence:
          return []
      vowels = "aeiouAEIOU"
      words = sentence.split()
      non_vowel_words = []
      for word in words:
          non_vowel_word = ''.join([char for char in word if char not in vowels])
          non_vowel_words.append(non_vowel_word)
      return non_vowel_words