AttributeError: type object ... has no attribute 'objects'

Question

fragment of models.py

class Hardware_type(models.Model):
    type = models.CharField(blank = False, max_length = 50, verbose_name="Type")
    description = models.TextField(blank = True, verbose_name="Description")
    slug = models.SlugField(unique = True, max_length = 255, verbose_name = "Slug")

class Software_type(models.Model):
    type = models.CharField(blank = False, max_length = 50, verbose_name="Type")
    description = models.TextField(blank = True, verbose_name="Description")
    slug = models.SlugField(unique = True, max_length = 255, verbose_name = "Slug")

and now

>>> sw = Software_type.objects.get(slug='unix')
>>> sw
<Software_type: Unix>
>>> hw = Hardware_type.objects.get(slug='printer')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
AttributeError: type object 'Hardware_type' has no attribute 'objects'

I can't see why this happens. Anyone can help me?

Edit:

sorry that did not sent all the code - problem solved. in another class I had

hardware_type = models.ManyToManyField(Hardware_type, verbose_name="Hardware Type")

after change from hardware_type to hw_type - works fine I did not know that can cause this problem.

>>> type(Hardware_type) <class 'django.db.models.base.ModelBase'> — Kubas
– Kubas, Commented Oct 17, 2011 at 6:06
As a side note, you really shouldn't be naming classes with underscores in Python. HardwareType and SoftwareType follow the common convention. — Soviut
– Soviut, Commented Apr 3, 2013 at 10:21
I had this problem too. What I did wrong was the give my serializer the same name as the model. So I changed the name of my serializer class to class fooSerializer ... — Red Cricket
– Red Cricket, Commented Sep 20, 2019 at 20:11

Ignacio Vazquez-Abrams · Accepted Answer · 2011-10-16 16:29:14Z

13

If you add a custom manager to a model then the default manager at objects will not be created. Either add it yourself in the class definition, or stick with using the custom manager.

answered Oct 16, 2011 at 16:29

Ignacio Vazquez-Abrams

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1 Comment

Frumples Over a year ago

As this answer suggests, one can add "objects = models.Manager()" to the class definition.

Udi · Accepted Answer · 2011-10-16 21:05:42Z

1

Your code works for me:

>>> hw = Hardware_type.objects.get(slug='111')
>>> hw
<Hardware_type: Hardware_type object>

~~However, using the keyword type might be a little dangerous, and probably you would like to avoid using it.~~

edited Oct 16, 2011 at 21:05

answered Oct 16, 2011 at 18:02

Udi

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2 Comments

Ignacio Vazquez-Abrams Over a year ago

type isn't a keyword, and using it as an attribute is safe.

Anthony Batchelor Over a year ago

Although, it is a built in function. Best to avoid it.

Kubas · Accepted Answer · 2011-10-27 19:11:01Z

1

it turned out that only began to work in django console,

Later I noticed that I have some old code in forms.py

class Hardware_type(forms.ModelForm):
    class Meta:
        model = Hardware_type

and thus it did not work, it was a bad day for naming classes, etc.

answered Oct 27, 2011 at 19:11

Kubas

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Comments

Lavina Khushlani · Accepted Answer · 2020-11-22 08:04:30Z

0

In my case, my model's meta class had abstract=True and i was using model.objects.all(). Since abstract cannot be instantiated, we cannot use this.

answered Nov 22, 2020 at 8:04

Lavina Khushlani

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