Django serializer gives 'str' object has no attribute '_meta' error
I am trying to make Django view that will give JSON responce with earliest and latest objects. But unfotunately it fails to work with this error.
'str' object has no attribute '_meta'
I have other serialization and it works.
Here is the code.
def get_calendar_limits(request):
result = serializers.serialize("json", Session.objects.aggregate(Max('date'), Min('date')), ensure_ascii=False)
return HttpResponse(result, mimetype="application/javascript")
Thanks a lot beforehand.
Asked by: Freddie930 | Posted: 06-12-2021
Answer 1
I get the same error when trying to serialize an object that is not derived from Django's Model
Answered by: Leonardo572 | Posted: 07-01-2022Answer 2
Python has "json" module. It can 'dumps' and 'loads' function. They can serialize and deserialize accordingly.
Answered by: Catherine542 | Posted: 07-01-2022Answer 3
Take a look at the following:
objects= Session.objects.aggregate(Max('date'), Min('date'))
print [ type[o] for o in objects ]
result = serializers.serialize("json", objects, ensure_ascii=False)
You might want to just run the above in interactive Python as an experiment.
What type are your objects? Is that type serializable?
Answered by: Dominik983 | Posted: 07-01-2022Similar questions
python - Changing name of json attribute in serializer
How can I change the name of a json field response given by the serializer from the Django Rest Framework?
After following the documentation I tried this, however it didn't work.
from api.models import Countries
from rest_framework import serializers
class CountrySerializer(serializers.Serializer):
country...
python - django rest 3.1.1 - one to many serializer with "many" attribute
I want to create a simple serializer that everyone who want will be able to add a Question with multi Answers (how many that he want)
one Question- multi Answers
I want to be able to add with the build in html form and not to edit the json.
my models:
class Question(models.Model):
question_text = models.CharField(max_length=30)
class Answer(models.Model...
python - Getting attribute error when trying to access the nested serializer in Django Rest Framework
I am getting following error while using the PostSerializer:
Got AttributeError when attempting to get a value for field
full_name on serializer UserSerializer. The serializer field might
be named incorrectly and not match any attribute or key on the long
instance. Original exception text was: 'long' object has no attribute
'full_name'.
...
python - Serializer List of objects grouping them by foreign key attribute
Similar to the issue found here (and maybe here)
I had the problem of having a model like so:
class Item(models.Model):
name = models.CharField(max_lengt...
python - Django - Add attribute to serializer and order list based on Foreign Key
what I'm trying to get a data based on foreign keys.
Let's say I have these models:
# models.py
class Player(models.Model):
name = models.CharField(max_length = 64)
class Game(models.Model):
score = models.IntegerField()
player = models.ForeignKey('Player', models.DO_NOTHING, related_name='player', blank=False, null=False)
class InjuredPlayer(models.Model):
player = models.ForeignKey('Play...
Python - Django - Pass serializer and attribute as argument
currently i am dealing with this snippet:
def to_representation(self, instance):
representation = super().to_representation(instance)
representation['categories'] = CategorySerializer(instance.categories, many=True).data
return representation
Now i would like to make the snippet
representation['categories'] = CategorySerializer(instance.categories, many=True)....
python - How to create a json attribute for a serializer method result
Here I have a serializer and in that serializer is a get_is_liked method.
This method is going to return a boolean, wheter the post has liked by the current user or not.
Now, I want to get the result of this method in the format of a json attribute like other fields.
There's suppose to be a mobile application that sends request for the logged in user to show if the post has liked before or not.
python - access attribute via serializer django
I got following models:
class OrderItem(models.Model):
ordered_amount = models.IntegerField(validators=[MinValueValidator(0)])
amount = models.IntegerField(default=0)
order = models.ForeignKey(
Order, on_delete=models.CASCADE, related_name="order_items"
)
class Order(models.Model):
reference = models.CharField(max_length=50)
purchase_order = models.CharField(max_length=15, ...
python - Add a new attribute in serializer but doesn't appear
I want to add a new attribute apartment_sold in the Transaction serializer, but I seem it doesn't work!
serializes.py
class TransactionSerializer(serializers.HyperlinkedModelSerializer):
buyer = serializers.ReadOnlyField(source='buyer.username')
apartment_sold = serializers.HyperlinkedRelatedField(view_name='sold-detail', read_only=True)
class Meta:
...
python - Django serializer for one object
I'm trying to figure out a way to serialize some Django model object to JSON format, something like:
j = Job.objects.get(pk=1)
##############################################
#a way to get the JSON for that j variable???
##############################################
I don't want:
from django.core import serializers
serializers.serialize('json', Job.objects.get(pk=1),ensure_...
python - Django Serializer returns JSON for parent class objects only and leave child objects as same?
I have these models:
class Projects(models.Model):
projectName =models.CharField(max_length = 100,unique=True,db_index=True)
projectManager = EmbeddedModelField('Users')
class Teams(models.Model):
teamType = models.CharField(max_length =100)
teamLeader = EmbeddedModelField('Users')
teamProject = EmbeddedModelField('Projects')
class Users(models.Model):
name = models.CharField(max_l...
python - Adding field that isn't in model to serializer in Django REST framework
I have a model Comment that when created may or may not create a new user. For this reason, my API requires a password field when creating a new comment. Here is my Comment model:
class Comment(models.Model):
commenter = models.ManyToManyField(Commenter)
email = models.EmailField(max_length=100)
author = models.CharField(max_length=100)
url = models.URLField(max_length=200)
content = mod...
python - Modifying the output from a serializer in the Django Rest Framework
I am using the django rest framework to output the content of an article. It works splendid, except now I want to modify the behavior to not return the full "content", but rather a teaser (of say the first 200 characters of the content but ideally I would like to be able to add any logic, say the end of the first sentence after 200 characters):
class ArticleSerializer(serializers.HyperlinkedModelSerializ...
python - Using the serpent serializer for safe object pickling
As I understand it, using serpent is safer than pickle for serializing objects.
I use the following class:
import serpent
class Test:
def save(self, fileName) :
ser = serpent.dumps({"schema": self}, indent=True)
open(fileName, "wb" ).write(ser)
def load(self, fileName) :
self = serpent.load(open(fileName, "rb"))["schema"]
def someFunction(self) :
...
python - Add user specific fields to Django REST Framework serializer
I want to add a field to a serializer that contains information specific to the user making the current request (I don't want to create a separate endpoint for this). Here is the way I did it:
The viewset:
class ArticleViewSet(viewsets.ModelViewSet):
queryset = Article.objects.all()
serializer_class = ArticleSerializer
filter_class = ArticleFilterSet
def prefetch_li...
python - Django Rest Framework serializer losing data
In my unittests, and in reality, the ModelSerializer class I've created just seems to discard a whole trove of data it is provided with:
class KeyboardSerializer(serializers.ModelSerializer):
user = serializers.Field(source='user.username')
mappings = KeyMapSerializer(many=True, source='*')
class Meta:
model = Keyboard
fields = ('user', 'label', 'is_primary', 'created', 'last_mo...
python - Changing name of json attribute in serializer
How can I change the name of a json field response given by the serializer from the Django Rest Framework?
After following the documentation I tried this, however it didn't work.
from api.models import Countries
from rest_framework import serializers
class CountrySerializer(serializers.Serializer):
country...
python - Create a nested serializer with Django Rest Framework, but without primary keys as identity
I have two models to expose via an API: every RegionValue has a ForeignKey to a MapAnswer. I wish to represent this in our API built using rest_framework by making the RegionValues a field inside the MapAnswer endpoint. My rest_framework serializers looks like this:
class RegionValueSerializer(serializers.ModelSeriali...
python - Rest framework serializer always returns False for is_valid
My serializer, quite basic:
class TestSerializer(serializers.Serializer):
date_time = serializers.DateTimeField()
wanted to try out from shell but I get False each time I try to check it for validation.
> import datetime
> s=TestSerializer({'date_time': datetime.datetime(year=2012,month=12,day=12)}
> s.data
{'date_time': datetime.datetime(2012, 12,...
Still can't find your answer? Check out these communities...
PySlackers | Full Stack Python | NHS Python | Pythonist Cafe | Hacker Earth | Discord Python