input: from typing import List
  
  def sort_words_by_length_and_alphabetical_order(my_string: str) -> str:
      """
      Sorts the words in a given string by their length in decreasing order and then by their alphabetical order.
      >>> sort_words_by_length_and_alphabetical_order("This is the string which is to be sorted")
      'string sorted which This is to be the'
      """
      
      words = my_string.split(' ') # split string into list of words 
    
      # create a list of tuples where the first element 
      # is the length of the word and the second element 
      # is the word itself  
      words_with_length = [(len(word), word) for word in words] 
    
      # sort list of tuples according to 1st element of tuple i.e. length of word 
      words_with_length.sort(reverse = True) 
    
      # wl contains list words in decreasing order of their length 
      # now use join() to join all words whith " " 
      sorted_string = " ".join([i[1] for i in words_with_length]) 
    
      # return sorted string 
      return sorted_string
output:     words_with_length.sort(key=lambda x: (-x[0], x[1]))
      return " ".join([word for length, word in words_with_length])