AttributeError：无法设置属性

Question

我正在处理一个遗留的 django 项目，在某个地方有一个定义如下的类；

 from django.http import HttpResponse

class Response(HttpResponse):
    def __init__(self, template='', calling_context='' status=None):
        self.template = template
        self.calling_context = calling_context
        HttpResponse.__init__(self, get_template(template).render(calling_context), status)

此类在视图中使用如下

def some_view(request):
    #do some stuff
    return Response('some_template.html', RequestContext(request, {'some keys': 'some values'}))

创建此类主要是为了让他们可以使用它在单元测试中执行断言。即他们不使用 django.test.Client 来测试视图，而是创建一个模拟请求并将其传递给查看（调用视图作为可调用的）在测试中如下

def test_for_some_view(self):
    mock_request = create_a_mock_request()
    #call the view, as a function
    response = some_view(mock_request) #returns an instance of the response class above
    self.assertEquals('some_template.html', response.template)
    self.assertEquals({}, response.context)

问题是测试套件进行到一半（相当大的测试套件）时，一些测试在执行

return Response('some_template.html', RequestContext(request, {'some keys': 'some values'}))

堆栈跟踪是

self.template = template
AttributeError: can't set attribute

完整的堆栈跟踪看起来像

======================================================================
ERROR: test_should_list_all_users_for_that_specific_sales_office
 ----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/austiine/Projects/mped/console/metrics/tests/unit/views/sales_office_views_test.py",   line 106, in test_should_list_all_users_for_that_specific_sales_office
    response = show(request, sales_office_id=sales_office.id)
File "/Users/austiine/Projects/mped/console/metrics/views/sales_office_views.py", line 63, in show
    "sales_office_users": sales_office_users}))
File "/Users/austiine/Projects/mped/console/metrics/utils/response.py", line 9, in __init__
    self.template = template
    AttributeError: can't set attribute

实际失败的测试是

def test_should_list_all_users_for_that_specific_sales_office(self):
    user_company = CompanyFactory.create()
    request = self.mock_request(user_company)
    #some other stuff

    #calling the view
    response = show(request, sales_office_id=sales_office.id)
    self.assertIn(user, response.calling_context["sales_office_users"])
    self.assertNotIn(user2, response.calling_context["sales_office_users"])

显示视图的代码

def show(request, sales_office_id):
    user = request.user
    sales_office = []
    sales_office_users = []
    associated_market_names = []
    try:
        sales_office = SalesOffice.objects.get(id=sales_office_id)
        sales_office_users = User.objects.filter(userprofile__sales_office=sales_office)
        associated_market_names = Market.objects.filter(id__in=           (sales_office.associated_markets.all())).values_list("name", flat=True)
        if user.groups.all()[0].name == UserProfile.COMPANY_AO:
            associated_market_names = [market.name for market in sales_office.get_sales_office_user_specific_markets(user)]
        except:
            pass
    return Response("sales_office/show.html", RequestContext(request, {'keys': 'values'}))

原文由 austiine 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

这个答案没有解决这个问题的细节，而是解释了潜在的问题。当您尝试更改的 属性 实际上是没有 setter 的属性时，会引发此特定异常“AttributeError：无法设置属性”（请参阅 source ）。如果您有权访问库的代码，添加一个 setter 就可以解决问题。

编辑：更新源链接到代码中的新位置。

编辑2：

二传手的例子：

 class MAMLMetaLearner(nn.Module):
    def __init__(
            self,
            args,
            base_model,

            inner_debug=False,
            target_type='classification'
    ):
        super().__init__()
        self.args = args  # args for experiment
        self.base_model = base_model
        assert base_model is args.model

        self.inner_debug = inner_debug
        self.target_type = target_type

    @property
    def lr_inner(self) -> float:
        return self.args.inner_lr

    @lr_inner.setter
    def lr_inner(self, new_val: float):
        self.args.inner_lr = new_val

原文由 yoniLavi 发布，翻译遵循 CC BY-SA 4.0 许可协议