[leetcode 10-04] 二、秘钥格式化

class Solution:
    def licenseKeyFormatting(self, s: str, k: int) -> str:
        sNew = s.upper()
        sNew_ls = list(sNew.split('-'))
        sNew_ls_str = list(''.join(sNew_ls) )
        #print(sNew_ls_str) 
        sNew_ls_reverse = sNew_ls_str[::-1]
        sOut = []
        for i in range(0,len(sNew_ls_reverse),k):
            if i+k > len(sNew_ls_reverse):
                sOut.append(sNew_ls_reverse[i:])
            else:
                sOut.append(sNew_ls_reverse[i:i+k])
        Out1 = []
        for strSingle in sOut:
            Out1.append(''.join(strSingle[::-1]))
        return '-'.join(Out1[::-1])

步骤：
1、全部变大写
2、split ‘-’
3、倒过去
4、选择k个
5、然后进行连接