## [171\.Excel表列序号](https://leetcode-cn.com/problems/excel-sheet-column-number/) > Easy ### 思路 ``` A->1 Z->26 ord(A)->65 ord(Z)->90 题目转换成一个26进制的数10进制的值 ``` ### 代码 python3 ``` class Solution: def titleToNumber(self, s: str) -> int: r = 0 for i in range(len(s)): r += 26 ** (len(s) - i - 1) * (ord(s[i]) - 64) return r ```