How do I find all indexes that have same string in a list?

Question

In a game of Hangman, if the hidden word is hello and the player guesses l then I need to find the index of both locations.

Example:

word = "hello"
guess = "l"
position = word.index(guess)     #this helps me find the first one

I couldn't come up with any way to find the second. How am I able to do that?

also answered here http://stackoverflow.com/questions/11122291/python-find-char-in-string-can-i-get-all-indexes#11122355 — ziddarth, Oct 11 '15 at 05:03

score 2 · Answer 1 · answered Oct 11 '15 at 04:53

2

Well, you could use enumerate and a list comprehension:

>>> s = "hello"
>>> indexes = [i for i, v in enumerate(s) if v == "l"]
>>> indexes
[2, 3]

answered Oct 11 '15 at 04:53

Games Brainiac

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score 0 · Answer 2 · answered Oct 11 '15 at 05:35

0

Specifically for hangman:

>>> word = 'hello'
>>> guess = 'l'
>>> puzzle = ''.join(i if i == guess else '_' for i in word)
>>> print(puzzle)
__ll_

answered Oct 11 '15 at 05:35

Burhan Khalid

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score 0 · Answer 3 · answered Oct 11 '15 at 09:57

Another thing you could do, is preprocess the word and have the list of indexes already available in a map so you do not have to iterate trough the string all the time, only once.

word = "hello"

map = {}

for i, c in enumerate(word):
    if (c in map):
        map[c].append(i)
    else:
        map[c] = [i]

Than, check that the letter guessed is in map. If it is, the letter exists otherwise it does not.

How do I find all indexes that have same string in a list?

3 Answers3