input: def is_last_char_alpha(txt):
      '''
      Construct a function that verifies if the final character
      in a given string is an alphabetical letter and not included 
      within a word, returning True if it is and False otherwise.
      Note: A "word" consists of characters separated by spaces.
  
      Examples:
      is_last_char_alpha("apple pie") ➞ False
      is_last_char_alpha("apple pi e") ➞ True
      is_last_char_alpha("apple pi e ") ➞ False
      is_last_char_alpha("") ➞ False 
      '''
output:     txt = txt.strip()
      if txt == "":
          return False
      return txt[-1].isalpha() and (len(txt) == 1 or txt[-2] == ' ')