认证Authentication
可以在配置文件中配置全局默认的认证方案
REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'rest_framework.authentication.BasicAuthentication',   # 基本认证
        'rest_framework.authentication.SessionAuthentication',  # session认证
    )
}
也可以在每个视图中通过设置authentication_classess属性来设置
from rest_framework.authentication import SessionAuthentication, BasicAuthentication
from rest_framework.views import APIView
class ExampleView(APIView):
    authentication_classes = (SessionAuthentication, BasicAuthentication)
    ...
认证失败会有两种可能的返回值:
- 401 Unauthorized 未认证
 - 403 Permission Denied 权限被禁止