How can I fix django rest framework metaclass conflict - django

Question

I am a beginner learning django rest framework and I just encounter this error and I can't seem to find a way around it. Here is the permissions.py sample code
from rest_framework import permissions
class UpdateOwnProfile(permissions, BaseException):
"""Allow user to edit their own profile"""
def has_object_permission(self, request, view, obj):
"""Check if user is trying to update their own profile"""
if request.method in permissions.SAFE_METHODS:
return True
return obj.id == request.user.id
Here is also a sample of the views.py sample codes
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from rest_framework import viewsets
from rest_framework.authentication import TokenAuthentication
from profiles_api import serializers
from profiles_api import models from profiles_api import permissions
class HelloApiView(APIView): """Test Api view""" serializer_class = serializers.HelloSerializer
def get(self, request, format=None):
"""Returns a list of Api features"""
an_apiview = [
'Uses HTTP methods as function (get, post, patch, put, delete)',
'Is similar to a traditional Django view',
'Gives you the most control over your application logic',
'Is mapped manually to URLs',
]
return Response({'message': 'Hello', 'an_apiview': an_apiview})
def post(self, request):
"""Create a hello message with our name"""
serializer = self.serializer_class(data=request.data)
if serializer.is_valid():
name = serializer.validated_data.get('name')
message = f'Hello {name}'
return Response({'message': message})
else:
return Response(
serializer.errors,
status = status.HTTP_400_BAD_REQUEST
)
def put(self, request, pk=None):
"""Handling updates of objects"""
return Response({'method': 'PUT'})
def patch(self, request, pk=None):
"""Handle a partial update of an object"""
return Response({'method': 'PATCH'})
def delete(self, request, pk=None):
"""Delete an object"""
return Response({'method': 'DELETE'})
class HelloViewset(viewsets.ViewSet): """Test API Viewset""" serializer_class = serializers.HelloSerializer
def list(self, request):
"""Return a hello message"""
a_viewset = [
'Uses actions (list, create, retrieve, update, partial update'
'Automatically maps to URLs using router'
'provides more functionality with less code'
]
return Response({'message': 'Hello', 'a_viewset': a_viewset})
def create(self, request):
"""Create a new hello message"""
serializer = self.serializer_class(data=request.data)
if serializer.is_valid():
name = serializer.validated_data.get('name')
message = f'Hello {name}!'
return Response({'message': message})
else:
return Response(
serializer.errors,
status=status.HTTP_400_BAD_REQUEST
)
def retrieve(self, request, pk=None):
"""Handle getting an object by its ID"""
return Response({'http_method': 'GET'})
def update(self, request, pk=None):
"""Handle updating an object"""
return Response({'http_method': 'PUT'})
def partial_update(self, request, pk=None):
"""Handle updating of an object"""
return Response({'http_method': 'PATCH'})
def destroy(self, request, pk=None):
"""Handle removing an object"""
return Response({'http_method': 'DELETE'})
class UserProfileViewSet(viewsets.ModelViewSet): """Handle creating and updating profiles""" serializer_class = serializers.UserProfileSerializer queryset = models.UserProfile.objects.all() authentication_classes = (TokenAuthentication,) permission_classes = (permissions.UpdateOwnProfile,)
And while running the development server I get this error:
class UpdateOwnProfile(permissions, BaseException): TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases

Answer 1

permissions (rest_framework.permissions) is of type module (whose type is type FWIW), but the type of BaseException is type (like all regular classes). So you have a metaclass conflict as expected.
Presumably, you meant to use permissions.BasePermission class from the module:
class UpdateOwnProfile(permissions.BasePermission, BaseException):
...
...
You can also import and refer the class directly:
from rest_framework.permissions import BasePermission
class UpdateOwnProfile(BasePermission, BaseException):
...
...