def solution(my_string, s, e):
strn = list(my_string)
strn[s:e+1] = strn[s:e+1:][::-1]
answer = ''.join(strn)
return answer
방법 1.
def solution(my_string, s, e):
return my_string[:s] + my_string[s:e+1][::-1] + my_string[e+1:]