Django框架开发项目时，在settings.py中设置 中文 语言时报错：
LANGUAGE_CODE = 'zh-Hans'
报错：ERRORS:
?: (translation.E004) You have provided a value for the LANGUAGE_CODE setting that is not in the LANGUAGES setting.
处理办法，头部引入：
from django.utils.translation import gettext_lazy as _
在LANGUAGE_CODE = 'zh-Hans' 上方添加：
LANGUAGES = [
('zh-Hans', _('Chinese')),
]
