錯誤：序列項 0：預期的 str 實例，找到 ForeignKey？

Question

我正在嘗試將我的 model 添加到我的 admin.py 頁面，我不得不玩弄我的 ManytoMany 和 Arrayfields 字段以使其正常工作，但是我還沒有擺脫困境。

我收到此錯誤： Error: sequence item 0: expected str instance, ForeignKey found 。

這是我原來的 model：

class Bucket(models.Model):

    options = (
        ('personal', 'Personal'),
        ('social', 'Social'),
    )


    class BucketObjects(models.Manager):
        def get_queryset(self):
            return super().get_queryset().filter(Bucket.owner)

    owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='buckets')
    users = models.ManyToManyField(settings.AUTH_USER_MODEL)
    category = models.CharField(max_length=30, choices=options)
    name = models.CharField(max_length=35)
    created = models.DateTimeField(default=timezone.now)
    slug = models.SlugField(unique=True, blank=True, null=True) 
    stock_count = models.IntegerField(blank=True, null=True)
    stock_list = ArrayField(models.CharField(max_length=6,null=True),size=30,null=True)
    about = models.CharField(max_length=75)

    objects = models.Manager()
    bucketobjects = BucketObjects()

    class Meta:
        ordering = ('-created',)

    def total_stocks_calc(self):
        self.stock_count = Bucket.objects.aggregate(Sum('stock_list', distinct=True))
        self.save()

    def get_absolute_url(self):
        return reverse("bucket:bucket-view", kwargs={"slug": self.slug})

    def __str__(self):
        return self.stock_list

這是我的admin.py代碼：

@admin.register(models.Bucket)
class AuthorAdmin(admin.ModelAdmin):
    fields = models.Bucket._meta.get_fields()
    list_display = ('id','owner','category', 'get_users', 'name', 'created',
                    'slug','stock_count','get_stocks', 'about')
    prepopulated_fields = {'slug': ('name',), }


    def get_users(self, obj):
        return "\n".join([u.users for u in obj.users.all()])
    
    def get_stocks(self, obj):
        return "\n".join([s.stock_list for s in obj.stock_list.all()])

不知道為什么我會收到這個錯誤。

編輯：完整的回溯錯誤：

Request Method: GET
Request URL: http://127.0.0.1:8000/bbucketmaster9/bucket/bucket/add/

Django Version: 3.1.4
Python Version: 3.8.5
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'rest_framework',
 'django_filters',
 'users',
 'bucket',
 'bucket_api']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback (most recent call last):
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/core/handlers/base.py", line 179, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/contrib/admin/options.py", line 614, in wrapper
    return self.admin_site.admin_view(view)(*args, **kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
    response = view_func(request, *args, **kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/views/decorators/cache.py", line 44, in _wrapped_view_func
    response = view_func(request, *args, **kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/contrib/admin/sites.py", line 233, in inner
    return view(request, *args, **kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/contrib/admin/options.py", line 1653, in add_view
    return self.changeform_view(request, None, form_url, extra_context)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/utils/decorators.py", line 43, in _wrapper
    return bound_method(*args, **kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
    response = view_func(request, *args, **kwargs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/contrib/admin/options.py", line 1534, in changeform_view
    return self._changeform_view(request, object_id, form_url, extra_context)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/contrib/admin/options.py", line 1568, in _changeform_view
    ModelForm = self.get_form(
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/contrib/admin/options.py", line 709, in get_form
    return modelform_factory(self.model, **defaults)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/forms/models.py", line 555, in modelform_factory
    return type(form)(class_name, (form,), form_class_attrs)
  File "/home/andres/stockbuckets.io/venv/lib/python3.8/site-packages/django/forms/models.py", line 266, in __new__
    message = message % (', '.join(missing_fields),

Exception Type: TypeError at /bbucketmaster9/bucket/bucket/add/
Exception Value: sequence item 0: expected str instance, ForeignKey found

Answer 1

您不能將models.Bucket._meta.get_fields()用於字段。 get_fields(…) [Django-doc]將返回字段本身的元組，而不是這些字段的名稱。

@admin.register(models.Bucket)
class AuthorAdmin(admin.ModelAdmin):
    fields = models.Bucket._meta.get_fields()

您可以明確列出字段的名稱，也可以使用

@admin.register(models.Bucket)
class AuthorAdmin(admin.ModelAdmin):
    fields = [f.name for f in models.Bucket._meta.get_fields()]

但您實際上不需要指定字段。 正如fields文檔所說：

如果既不存在fields也不存在字段集選項，則fieldsets將默認顯示每個不是AutoField且具有editable=True的字段，在單個字段集中，其順序與在 model 中定義的字段順序相同。