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.

As a side note, you really shouldn't be naming classes with underscores in Python. `HardwareType` and `SoftwareType` follow the common convention. — Soviut, Apr 03 '13 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, Sep 20 '19 at 20:11

score 13 · Answer 1 · answered Oct 16 '11 at 16:29

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 '11 at 16:29

Ignacio Vazquez-Abrams

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As this answer suggests, one can add "objects = models.Manager()" to the class definition. – Frumples Aug 19 '16 at 18:19

Udi · Answer 2 · 2011-10-16T21:05:42.763

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 '11 at 21:05

answered Oct 16 '11 at 18:02

Udi

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`type` isn't a keyword, and using it as an attribute is safe. – Ignacio Vazquez-Abrams Oct 16 '11 at 20:56
Although, it is a built in function. Best to avoid it. – Anthony Batchelor Dec 13 '11 at 08:49

score 1 · Accepted Answer · answered Oct 27 '11 at 19:11

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.

score 0 · Answer 4 · answered Nov 22 '20 at 08:04

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 '20 at 08:04

Lavina Khushlani

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

4 Answers4