帮改正，求解，2222

def changeinfo(info):
s=''
for i in range(len(info)-1,-1,-1):
s+=str((int(info[i])+5)%10)
return s
n=input()
if len(n)>4:
print('illegal input'

def changeinfo(info):
    s=''
    for i in range(len(info)-1,-1,-1):
        s+=str((int(info[i])+5)%10)
    return s    
n=input()
if len(n)>4:
    print('illegal input')
else:
    n='0'*(4-len(n))+n
    print(changeinfo(n))

def changeinfo(info):
	str1 = str(info)
	s = ''
	for i in range(len(str1) - 1, -1, -1):
		s += str((int(str1[i]) + 5) % 10)
	return s

你应该没写全吧？不过changeinfo里面的内容可以改成这样