题解 | 字符串变形

#python
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param s string字符串 
# @param n int整型 
# @return string字符串
#
class Solution:
    def trans(self , s: str, n: int) -> str:
        # write code here
        res = ''
        for i in range(n):
            if 'A' <= s[i] <='Z':
                res += s[i].lower()
            elif 'a' <= s[i] <= 'z':
                res += s[i].upper()
            else:
                res += s[i]

        word_list = res.split(' ')
        reversed_word_list = word_list[::-1]
        return ' '.join(reversed_word_list)