mt_

这是我的完整解决方案;

class StudentAdmin(admin.ModelAdmin):

    def get_queryset(self,request):
        # if principal (not district user) only show students
        # whose classroom is in principal's school

        qs = super(StudentAdmin, self).get_queryset(request)
        if request.user.is_superuser:
            return qs
        else:
            groups = [group.name for group in request.user.groups.all()]
            if 'principal' in groups:
                school = request.user.principal.school
                return qs.filter(room__school=school)
            else:
                return qs

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        # if principal (not district administrator) 
        # limit transfer to within principal's school

        from login.models import Room
        groups = [group.name for group in request.user.groups.all()]
        if 'principal' in groups:
            schoolname = request.user.principal.school.name
            print(db_field)
            print(type(db_field))
            if db_field.name == 'room':
                print("match")
                kwargs['queryset'] = Room.objects.filter(school__name=schoolname)
        return super().formfield_for_foreignkey(db_field, request, **kwargs)


    class CustomRoom(admin.SimpleListFilter):
        # if principal (not district user)
        # only offer filter to classrooms in principal's school  

        title = 'Classroom'
        parameter_name = 'classroom'

        def lookups(self,request,model_admin):
            from login.models import Room,School
            groups = [group.name for group in request.user.groups.all()]
            if 'principal' in groups:
                school = request.user.principal.school
                rooms = Room.objects.filter(school=school)
                return ((room.id,room.roomno) for room in rooms)
            else:
                rooms = Room.objects.all()
                return ((room.id,room.roomno) for room in rooms)

        def queryset(self,request,queryset):
            selected = self.value()

            # WAS return queryset.filter(room=selected)
            # this does not handle All case correctly 

            if selected:
                return queryset.filter(room=selected)
            else:
                 return queryset


    list_display = ('surname','givennames', 'room')
    list_filter=('enrolled',CustomRoom,)

# Register the admin class with the associated model
admin.site.register(Student, StudentAdmin)

比我想的要凌乱一点,但如果你把它看成是三个独立的小步,那就不算太可怕了。