题解 | #禁止重复注册#

import sys

cu = ['Niuniu', 'Niumei', 'GURR', 'LOLO']
cu_l = [j.lower() for j in cu]
nu = ['GurR', 'Niu Ke Le', 'LoLo', 'Tuo Rui Chi']
for i in nu:
    if i.lower() in cu_l:
        print('The user name {} has already been registered! Please change it and try again!'.format(i))
    else:
        print('Congratulations, the user name {} is available!'.format(i))