def first_unique_char ( s ) : if ( len ( s ) == 1 ) : return 0 ban = [ ] for i in range ( len ( s ) ) : if all ( s [ i ] != s [ k ] for k in range ( i + 1 , len ( s ) ) ) == True and s [ i ] not in ban : return i else : ban . append ( s [ i ] ) return - 1
python determine if a string contains unique characters
: type s : str : rtype : int
def first_unique_char(s):
    """
    :type s: str
    :rtype: int
    """
    if (len(s) == 1):
        return 0
    ban = []
    for i in range(len(s)):
        if all(s[i] != s[k] for k in range(i + 1, len(s))) == True and s[i] not in ban:
            return i
        else:
            ban.append(s[i])
    return -1