input: Write a function that takes a list of words and a prefix, and returns a list of words that start with the given prefix.
  
  assert auto_complete(["dog", "deer", "deal", "dungeon", "dark", "dusk"], "d")==['dog', 'deer', 'deal', 'dungeon', 'dark', 'dusk']
  assert auto_complete(["apple", "apricot", "banana", "cherry"], "ap")==['apple', 'apricot']
  assert auto_complete(["moon", "monk", "monkey", "monday"], "mo")==['moon', 'monk', 'monkey', 'monday']
  assert auto_complete(["carrot", "celery", "cabbage", "cucumber"], "ce")==['celery']
  assert auto_complete(["guitar", "grand", "grape", "glass"], "gr")==['guitar', 'grand', 'grape', 'glass']
  assert auto_complete([], "a")==[]
output: def auto_complete(words, prefix):
      return [word for word in words if word.startswith(prefix)]