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.")==['This', 'machine', 'learning', 'project', 'is', 'challenging']
  assert extract_words("Python is great")==[]
  assert extract_words("Why not try it?")==['Why', 'not', 'try', 'it?']
  assert extract_words("Rhythm")==['Rhythm']
  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