凯撒密码方式加密代码

在Python输入一段数字和字母以凯撒密码的加密方法输出结果

s = input()
t = ""
for c in s:
     if 'a' <= c <= 'z':
        t += chr( ord('a') + ((ord(c)-ord('a')) + 3 )%26 )
    elif 'A' <= c <= 'Z':
        t += chr( ord('A') + ((ord(c)-ord('A')) + 3 )%26 )
    else:
        t += c
print(t)