IntegrityError:使用django tasty pie登录用户时，重复的键值违反了唯一约束

这是我的UserLoginResource：

class UserLoginResource(ModelResource):

    class Meta:
        object_class = User
        queryset = User.objects.all()
        allowed_methods = ['post','get']
        include_resource_uri = False
        resource_name = 'login'
        excludes = ['is_active','is_staff','is_superuser']
        authentication = SillyAuthentication()
        authorization = SillyAuthorization()

    def obj_create(self, bundle, request=None, **kwargs):
        try:
            bundle = super(UserLoginResource, self).obj_create(bundle,request,**kwargs)
            bundle.obj.set_password(bundle.data.get('password'))
            bundle.obj.set_username(bundle.data.get('username'))
            bundle.obj.save() 
            return bundle
        except IntegrityError:
            raise BadRequest('The username exists')

    def dehydrate(self,bundle):
        bundle.data['custom_field'] = "Whatever you want"
        return bundle

当我使用已经存在的用户名和密码发布时，它会给出一个500错误，表示完整性错误，并且用户名已经存在

如何登录

即使有错误（假设用户名不存在，如何美化错误响应

使用此代码，您正在创建用户对象，而不是登录

请参阅tastype.validation