input: def is_last_character_alpha(txt):
      '''
      Develop a function that determines whether the last character
      of a given string is an alphabetical character and is not 
      within a word. The function should return True or False accordingly.
      Note: A "word" is defined as a cluster of characters separated by a space.
  
      Examples:
      is_last_character_alpha("apple pie") ➞ False
      is_last_character_alpha("apple pi e") ➞ True
      is_last_character_alpha("apple pi e ") ➞ False
      is_last_character_alpha("") ➞ False 
      '''
output:     if not txt or txt[-1].isspace():
          return False
      words = txt.split()
      last_word = words[-1]
      return last_word.isalpha() and len(last_word) == 1