小练习-excel行转换

def titleToNumber(self, s):

    """

    :type s: str

    :rtype: int

    """

    base = ord("A")-1

    res = 0

    i = 0

    for x in s[::-1]:

        res = res + (ord(x) - base) * 26**i

        i += 1

    return res