超笨的方法


str_1 = input()
str_2 = ''
alpha_str = 'abcdefghijklmnopqrstuvwxyz'
alpha = list(alpha_str) 
alpha_upper = list(alpha_str.upper())
for i in str_1:
    if i in alpha[0:3]:
        i=2
    if i in alpha[3:6]:
        i=3
    if i in alpha[6:9]:
        i=4
    if i in alpha[9:12]:
        i=5
    if i in alpha[12:15]:
        i=6
    if i in alpha[15:19]:
        i=7
    if i in alpha[19:22]:
        i=8
    if i in alpha[22:26]:
        i=9
    if i in alpha_upper[:-1]:
        i = alpha_upper[alpha_upper.index(i)+1].lower()
    if i == 'Z':
        i = 'a'
    str_2 += str(i)
print(str_2)