input: from typing import List
  
  
  def reverse_words(sentence: str) -> str:
      """ Reverse the order of words in a sentence but keep the order of the 
      characters in each word the same.
      >>> reverse_words("This is a sentence.")
      "sentence. a is This"
      >>> reverse_words("Hello world")
      "world Hello"
      """
      words = sentence.split()
      reversed_words = words[::-1]
      return ' '.join(reversed_words)
output:     words = sentence.split()
      reversed_words = words[::-1]
      return ' '.join(reversed_words)