1 class Solution: 2 def reverseStr(self, s: str, k: int) -> str: 3 begin,lens,ans = 0,len(s),'' 4 while begin < lens: 5 mid = begin + k 6 if mid >= lens: 7 ans += s[begin:][::-1] 8 else: 9 ans += s[begin:mid][::-1]+s[mid:mid+k] 10 begin += 2 * k 11 return ans