Python 凯撒密码

https://python123.io/student/courses/5028/groups/64412/problems/programmings/6921#pagetop

inputStr input()
buffer 
for i in inputStr:
 if a i z :
 buffer chr(ord( a ) ((ord(i) - ord( a ) 3) % 26))
 elif A i Z :
 buffer chr(ord( A ) ((ord(i) - ord( A ) 3) % 26))
 else:
 buffer i
print(buffer)