BEGIN:
创建Flask实例app时,利用template_folder 和 static_folder参数进行自定义设置
app = Flask(<app_name>, instance_path=INSTANCE_FOLDER_PATH, instance_relative_config=True, template_folder='frontend/templates', static_folder='frontend/static', )
ps: <app_name>指的是你的app的项目名称,或则可以是默认:__name__
END.