input: from typing import List
  
  def replace_words(sentence: str, old_word: str, new_word: str) -> str:
      """
      Replace a given word in the sentence with another word.
      >>> replace_words("I love walking on the beach", "walking", "swimming")
      "I love swimming on the beach"
      >>> replace_words("Python is fun", "fun", "amazing")
      "Python is amazing"
      """
      return sentence.replace(old_word, new_word)
output:     return sentence.replace(old_word, new_word)