题解 | #禁止重复注册#

# 创建current_users列表
current_users = ['Niuniu','Niumei','GURR','LOLO']
# 创建new_users列表
new_users = ['GurR','Niu Ke Le','LoLo','Tuo Rui Chi']
# for循环遍历
for user in new_users:
    if (user.capitalize() in current_users) or (user.upper() in current_users) :
        print('The user name %s has already been registered! Please change it and try again!' %user)
    else:
        print(f'Congratulations, the user name {user} is available!')

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

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