def char_index(word, char):
    try:
        return [word.index(char), word.rindex(char)]
    except:
        return None

e84fa4669633c9f10f233661623035d243d5e846
<mask token>

def char_index(word, char):
    try:
        return [word.index(char), word.rindex(char)]
    except:
        return None
