题解 | #禁止重复注册#

current_users=['Niuniu','Niumei','GURR','LOLO']
new_users=['GurR','Niu Ke Le','LoLo','Tuo Rui Chi']

# （注：用户名的比较不区分大小写）
# current_users_1=[i.lower() for i in current_users]
# new_users_1=[i.lower() for i in new_users]
#不能实现需求，因为需要输出原格式的名字


for i in new_users:
    # if i in current_users:
    if i.lower() in [i.lower() for i in current_users]:
        print('The user name %s has already been registered! Please change it and try again!'%(i))
    else:
        print('Congratulations, the user name %s is available!'%(i))