beginning of hangman | Python Fiddle

def available_letters(letters_string, guessed_letter):
    letters_list = list(letters_string)
    index_list = find_letter(letters_list, guessed_letter)
    for index in index_list:
    	del letters_list[index]
    letters_string = ''.join(letters_list)
    #print "letters_string within the function", letters_string
    return letters_string

def find_letter(word, guessed_letter): ###Returns a list of index values of where the letter occurs.
    index = 0
    index_list = []
    for letter in word:
        if letter == guessed_letter:
            index_list = index_list + [index,]
        index +=1
    return index_list
### Use this to determine whether a guess is good or not. If index_list =/ None, then guess is good. But estimate how many lines of code would be run through each time.

def update_available_letters(letters_string, guessed_letter):  ###Tracks which letters haven't been guessed yet.
    index = 0
    while index < len(letters_string):
        if letters_string[index] == guessed_letter:
            letters_list = list(letters_string)
            del letters_list[index]
            letters_string = ''.join(letters_list)
            return letters_string
        index += 1
    return -1

def update_word(word_blanks, guessed_letter, index_list):
	for index in index_list:    
		word_blanks[index] = guessed_letter
		##print word_blanks
	return word_blanks

word = "cheese"
print word
print "Welcome to the game, Hangman!"
print "I'm thinking of a word that is", len(word), "letters long."
letters_string = "abcdefghijklmnopqrstuvwxyz"
word_blanks = ["_",]*len(word)

for guess_number in range(26,1,-1):
    if guess_number==1:
        print "You have", guess_number, "guess left."
    else:
    	print "You have", guess_number, "guesses left."
    print "Available letters:", letters_string
    guessed_letter = raw_input ("Please guess a letter:")
    guessed_letter = guessed_letter.lower()
    #print guessed_letter
    index_list = find_letter(word, guessed_letter)
    #print index_list
    letters_string = update_available_letters(letters_string, guessed_letter) #updates which letters are available
    print "letters string:", letters_string
    
    if guessed_letter in word:
        word_blanks = update_word(word_blanks, guessed_letter, index_list)
        delimiter = ' '
	updated_word = delimiter.join(word_blanks)
        print "Good guess:", updated_word
    else:
        print "Oops! That letter is not in my word:", updated_word

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