input: Write a function to sort words in a given string by their length in decreasing alphabetical order. The function should return the sorted string as output. If the input string is empty, the function should return an empty string.
  def sort_words_by_length(my_string):
      if my_string == "":
          return ""
      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("This is the string which is to be sorted")=="string which be the to is sorted This"
  assert sort_words_by_length("Python is awesome")=="awesome Python is"
  assert sort_words_by_length("Short example here")=="example Short here"
  assert sort_words_by_length("")==""
output: def sort_words_by_length(my_string):
      if my_string == "":
          return ""
      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