input: Write a function to sort words in a given string by their length in decreasing alphabetical order.
  def sort_words_by_length_and_alpha(my_string):
      words = my_string.split(' ')
      words_with_length = [(len(word), word) for word in words]
      words_with_length.sort(reverse = True)
      sorted_string = " ".join([i[1] for i in words_with_length])
      return sorted_string
  assert sort_words_by_length_and_alpha("This is the string which is to be sorted")=="which string sorted the This is be to"
  assert sort_words_by_length_and_alpha("Python programming is fun")=="programming Python fun is"
  assert sort_words_by_length_and_alpha("apple banana cherry")=="banana cherry apple"
  assert sort_words_by_length_and_alpha("sort this list please")=="please sorted list this"
  assert sort_words_by_length_and_alpha("")==""
output: def sort_words_by_length_and_alpha(my_string):
      words = my_string.split(' ')
      words_with_length = [(len(word), word) for word in words]
      words_with_length.sort(reverse=True)
      sorted_string = " ".join([i[1] for i in words_with_length])
      return sorted_string