Count number of letters until one letters has changed

I want to count number of same letter at beginning between two words (letter by letter) until there’s one different and return who has the most same letter.

This is my code :

def same(word, liste):
    letter = 0
    dico = dict()
    for i in liste:
        while word[letter] == i[letter]:
            letter += 1;
        dico[i] = letter;
        letter = 0;
    
    same = max(dico, key=dico.get)
    return same

But i get always this error of string index out of range, I’ve tried with much way but nothing

    while word[letter] == i[letter]:

IndexError: string index out of range

In input :

same('hello',['hi,'hell','helo'])

Output:

'hell'

Thanks

Answer

you can’t go out of range in your while verify the length of your word before word[letter] == i[letter] while letter < len(word) and letter < len(i) and word[letter] == i[letter]:

gives you :

def same(word, liste):
    letter = 0
    dico = dict()
    for i in liste:
        while letter < len(word) and letter < len(i) and  word[letter] == i[letter]:
            letter += 1;
        dico[i] = letter;
        letter = 0;
    
    same = max(dico, key=dico.get)
    return same

print(same('blablabla',['blaze','bli']))

----------
>>> blaze