Trying to solve an exercise

[frafrog]

Hello, I'm trying to solve this exercise from the book think python :
Exercise 9.6. Write a function called is_abecedarian that returns True if the letters in a word
appear in alphabetical order (double letters are ok). How many abecedarian words are there?

This is my solution :

def is_abecedarian(w):
    w = w.lower()
    if len(w) <= 1 :
        return True
    elif ord(w[0]) > ord(w[1]) :
        return False
    else :
        is_abecedarian(w[1:])

When I try to run the script it returns None. I don't uderstand why...

[BashBedlam]

Your return statements are not making it back through the recursions. Change the last line in your function to this :

return (is_abecedarian(w[1:]))

So the whole thing is:

def is_abecedarian(w):
	w = w.lower()
	if len(w) < 2:
		return True
	elif ord(w[0]) > ord(w[1]) :
		return False
	else :
		return (is_abecedarian(w[1:]))

print (is_abecedarian ('abcdefg'))

output = True

[frafrog]

how did i miss that? thx

[Larz60+]

I believe you have worked on this for a while, so think of this:

• set return value variable to True
  
• if length of word is not 1
  
• get idx of 1 to length of word (hint use a loop)
  
• if word[idx-1] > word[idx} then
  • set return value to False
    
  • exit loop
    
• return value
  

def is_abecedarian(w):
    retval = True
    if not len(w) == 1:
        for i in range(1, len(w)):
            if w[i-1] > w[i]:
                retval = False
                break
    return retval