如何在django-rest-framework自定义权限类中为每个条件设置不同的消息值？

from rest_framework.permissions import BasePermission

class CustomPermission(BasePermission):
    message = {
        'condition1': '消息1',
        'condition2': '消息2',
        'condition3': '消息3',
    }

    def has_permission(self, request, view):
        # 根据条件判断权限
        if condition1:
            self.message = self.message['condition1']
            return True
        elif condition2:
            self.message = self.message['condition2']
            return True
        elif condition3:
            self.message = self.message['condition3']
            return True
        else:
            return False

from rest_framework.views import APIView
from .permissions import CustomPermission

class MyView(APIView):
    permission_classes = [CustomPermission]
    ...