python实现数字0开始的索引，对应Execl的字母方法

import re
 
col = row = []
 
# 输入正确格式的定位，A2,AA2有效，AAB2无效
while len(col) == 0 or len(row) == 0 or len(col) > 1 or len(row) > 1:
    colrow = input('请输入单元格位置（例如B3,AAB3,a2, aaB4）：')
    col = re.findall('([A-Za-z]+)\w+', colrow)
    row = re.findall('\w+(\d+)', colrow)
    if len(col[0]) > 2: col = [] #只接受两位字母的列标，超过2位的无效，A，AB有效，AAB无效
 
row = int(row[0]) #行标
col = col[0]
 
# 输入为A2类型
if len(col) == 1:
    col = ord(col.upper())-ord('A') + 1
# 输入为AA2类型
elif len(col) == 2:
    col_1 = ord(col[0].upper())-ord('A') + 1
    col_2 = ord(col[1].upper())-ord('A') + 1
    col = col_1*26 + col_2
     
# 获取行列数
print('Column:',col , '/ Row: ',row)

import string

letter = string.ascii_uppercase

def num_to_letter(col, row):
  row = str(row+1)
  if col < 26:
    index = col + ord('A')
    return chr(index)+row
  else:
    col_1 = (col // 26) - 1
    col_2 = (col % 26)
    return letter[col_1]+letter[col_2]+row

print(num_to_letter(4, 4))