leetcode Excel Sheet Column Number python

Excel Sheet Column Number

Related to question Excel Sheet Column Title

Given a column title as appear in an Excel sheet, return its corresponding column number.

For example:

    A -> 1
    B -> 2
    C -> 3
    ...
    Z -> 26
    AA -> 27
    AB -> 28 python code

class Solution:
# @param {string} s
# @return {integer}
def titleToNumber(self,s):
　　ss=list(s)
　　summ=0
　　while len(ss)>=1:
　　　　num=(ord(ss[0])-64)　　　　#26进制
　　　　summ=summ*26+num
　　　　ss.pop(0)
　　return summ