Django异常DoesNotExist

我有一个模型同时具有Django的模型字段和python属性。 例如:

编辑2:更新与实际模型(对于葡萄牙的名字抱歉)

#On Produto.models.py
from django.db          import models
from django.forms       import ModelForm
from openshift.models   import AbstractModel

from openshift.produto.models import app_name


class Produto(models.Model):

    class Meta:
        app_label = app_name


    descricao = models.CharField(max_length=128)    
    und_choices = (
        ('UND', 'Unidade'),
        ('M',     'Metro'),
        ('Kg',     'Quilograma'),
        ('PC',     'Peça'),
    )
    unidade   = models.CharField(max_length=3, choices=und_choices, default='UND')

#On Estoque.models.py

from django.db          import models
from django.forms       import ModelForm
from openshift.models   import AbstractModel
from produto.models     import Produto

from openshift.estoque.models import app_name

class Estoque(models.Model):

    class Meta:
        app_label = app_name

    id = models.IntegerField(primary_key=True)
    produtoid   = models.ForeignKey(Produto, unique=True)
    quantidade  = models.DecimalField(max_digits=20, decimal_places=4)
    valorunit   = models.DecimalField(max_digits=20, decimal_places=4)
    valortotal  = models.DecimalField(max_digits=20, decimal_places=2)   


    _field_labels = {
        "id" : r"Código", 
        "produtoid"  : r"Produto", 
        "quantidade" : r"Quantidade",
        "valorunit" : r"Valor Unitário",
        "valortotal" : r"Valor Total"
    }

    _view_order = ['id', 'produtoid', 'quantidade', 'valorunit', 'valortotal']

    @property
    def Vars(self):
        return {'field_labels': self._field_labels, 'view_order': self._view_order}

#on project.views.main_request

obj = get_model('Estoque', 'Estoque')().Vars #Here is where the Exception triggers.

如果我在调用save()方法(在创建模型记录期间)之前尝试调用属性“Vars”,即使“Vars”属性不是django模型的一部分,django也会不断提升DoesNotExist异常。

任何人都可以解释为什么会发生?

编辑:按要求:

Django跟踪:

追溯:

文件“/home/gleal/cbengine/local/lib/python2.7/site-packages/django/core/handlers/base.py”在get_response 111中。response = callback(request,* callback_args,** callback_kwargs)

请求48中的文件“/home/gleal/cbengine/engine/wsgi/openshift/views.py”。return browse(request,app,model,var_dict,False)

文件“/home/gleal/cbengine/engine/wsgi/openshift/../openshift/subviews/browse.py”in _browse 32. custom_vars ['TableColspan'] = len(obj.Vars.get('VIEW_ORDER',{ }))

文件“/home/gleal/cbengine/engine/wsgi/openshift/../openshift/models.py”在Vars 40中。curr_vals [field.name] = getattr(self,field.name)文件“/ home / gleal / cbengine / local / lib / python2.7 / site-packages / django / db / models / fields / related.py“in get 343. raise self.field.rel.to.DoesNotExist

异常类型:DoesNotExist at / estoque / estoque / browse / Exception Value:


刚才发现那个伟大的恶棍是方法Vars上的@property装饰器。

它让django尝试从类的实例中获取值,并且在某些情况下,它可能会触发Django的ORM所做的一些查询(基本上,在我尝试从当前实例中获取值的情况下)。

我将@property更改为@classmethod,一切都像魅力一样。 喜欢这个:

#before
@property
def Vars(self):
    return {'field_labels': self._field_labels, 'view_order': self._view_order}

#after
@classmethod
def Vars(self):
    return {'field_labels': self._field_labels, 'view_order': self._view_order}

感谢任何试图帮助的人!

链接地址: http://www.djcxy.com/p/55907.html

上一篇: Django Exception DoesNotExist

下一篇: 'long' object has no attribute 'fetchall'