문제 설명 및 제한조건

나의 풀이
Big = {0:'A',1:'B',2:'C',3:'D',4:'E',5:'F',6:'G',7:'H',8:'I',9:'J',10:'K',11:'L',12:'M',13:'N',14:'O',15:'P',16:'Q',17:'R',18:'S',19:'T',20:'U',21:'V',22:'W',23:'X',24:'Y',25:'Z'}
little = {0:'a',1:'b',2:'c',3:'d',4:'e',5:'f',6:'g',7:'h',8:'i',9:'j',10:'k',11:'l',12:'m',13:'n',14:'o',15:'p',16:'q',17:'r',18:'s',19:'t',20:'u',21:'v',22:'w',23:'x',24:'y',25:'z'}
def solution(s, n):
answer = ''
for i in range(len(s)):
if s[i] == ' ':
answer += ' '
for j in range(26):
if s[i] == Big[j]:
answer += Big[(j+n)%26]
elif s[i] == little[j]:
answer += little[(j+n)%26]
return answer