input: Write a function to design a machine learning algorithm in Python that can identify whether a given sentence is an 'affirmative' sentence or a 'negative' sentence. If the sentence is affirmative, return "Affirmative"; otherwise, return "Negative". If the given sentence is empty, return "Affirmative".
  
  assert isAffirmativeorNegative("He always comes late but I dont mind.") == "Negative"
  assert isAffirmativeorNegative("I love this movie.") == "Affirmative"
  assert isAffirmativeorNegative("I never eat vegetables.") == "Negative"
  assert isAffirmativeorNegative("") == "Affirmative"
output: def isAffirmativeorNegative(sentence):
      if not sentence:
          return "Affirmative"
      negative_words = ["not", "never", "dont", "doesnt", "wont", "cant"]
      words = sentence.lower().split()
      for word in words:
          if word in negative_words:
              return "Negative"
      return "Affirmative"