input: from typing import List
  
  def extract_words(sentence: str) -> List[str]:
      """Extracts words that contain no vowels from a given sentence.
      >>> extract_words("This machine learning project is challenging.")
      ['This', 'h', 'M', 'chlngng']
      """
output:     vowels = "aeiouAEIOU"
      words = sentence.split()
      result = []
      for word in words:
          if any(char in vowels for char in word):
              result.append(word)
          else:
              result.append(''.join([char for char in word if char not in vowels]))
      return result