python solution
class Solution:\n    def reverseStr(self, s: str, k: int) -> str:\n        \n        ab=""\n        i=0\n        while i<len(s):\n            bg=s[i:i+k]\n     
class Solution:\n    def reverseStr(self, s: str, k: int) -> str:\n        \n        ab=""\n        i=0\n        while i<len(s):\n            bg=s[i:i+k]\n            ab=ab+bg[::-1]+s[i+k:i+2*k]\n            i+=2*k\n        return ab
['Python', 'Python3']