Answers for "django custom permissions"

django authenticate with email

from django.contrib.auth import get_user_model
from django.contrib.auth.backends import ModelBackend

class EmailBackend(ModelBackend):
    def authenticate(self, request, username=None, password=None, **kwargs):
        UserModel = get_user_model()
        try:
            user = UserModel.objects.get(email=username)
        except UserModel.DoesNotExist:
            return None
        else:
            if user.check_password(password):
                return user
        return None

django permissions

def my_view(request):
    # Individual permissions
    permissions = Permission.objects.filter(user=request.user)

    # Permissions that the user has via a group
    group_permissions = Permission.objects.filter(group__user=request.user)

django group permissions method

group.permissions.set([permission_list])
group.permissions.add(permission, permission, ...)
group.permissions.remove(permission, permission, ...)
group.permissions.clear()