7

I am develop a simple rest api using Django 1.10 When I run my server and call app url I get an error:

TypeError: __init__() takes 1 positional argument but 2 were given

GET /demo/ HTTP/1.1" 500 64736

Traceback

Environment: Request Method: GET Request URL: http://localhost:8000/demo/ Django Version: 1.10.4 Python Version: 3.5.2 Installed Applications: ['django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', 'mydemoapp', 'rest_framework'] 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: File "/home/aqib/DjangoProject/mydemoenv/lib/python3.5/site- packages/django/core/handlers/exception.py" in inner 39. response = get_response(request) File "/home/aqib/DjangoProject/mydemoenv/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response 187. response = self.process_exception_by_middleware(e, request) File "/home/aqib/DjangoProject/mydemoenv/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response 185. response = wrapped_callback(request, *callback_args, **callback_kwargs) Exception Type: TypeError at /demo/ Exception Value: __init__() takes 1 positional argument but 2 were given

models.py

from django.db import models class ProfileModel(models.Model): name = models.CharField(max_length=30, blank=False, default='Your Name') address = models.CharField(max_length=100, blank=True) contact = models.IntegerField() def __str__(self): return '%s %s' % (self.name, self.address)

views.py

from django.shortcuts import render from rest_framework import viewsets from mydemoapp.models import ProfileModel from .serializers import ProfileSerializer class ProfileView(viewsets.ModelViewSet): profile = ProfileModel.objects.all() serializer_class = ProfileSerializer

serializers.py

from .models import ProfileModel from rest_framework import serializers class ProfileSerializer(serializers.ModelSerializer): class Meta: model = ProfileModel fields = ('name', 'address', 'contact')

urls.py (Application Url)

from django.conf.urls import url from mydemoapp import views urlpatterns = [ url(r'^$', views.ProfileView), ]

urls.py (project url)

from django.conf.urls import url, include from django.contrib import admin urlpatterns = [ url(r'^admin/', admin.site.urls), url(r'^demo/', include('mydemoapp.urls')), ]
Improve this question
8
  • 2
    Any reason for using Django? Seems excessive for just a simple REST API Commented Dec 7, 2016 at 7:14
  • 3
    Can we have a more complete traceback/example? When is this being executed? What file? Upon what call? Commented Dec 7, 2016 at 7:14
  • @cricket_007 Not relevant, but not untrue. Commented Dec 7, 2016 at 7:15
  • @MohdAqib That's hardly more information. is the exception being raised or handled? Have you ran through with a debugger at all? Commented Dec 7, 2016 at 7:20
  • 1
    you have to show full traceback Commented Dec 7, 2016 at 7:24

2 Answers 2

Reset to default
8

This very silly mistake I do too often. This is because of the urls.py(Application). Always remember to call the .as_view() method

Wrong

urls.py

from django.conf.urls import url from mydemoapp import views urlpatterns = [ url(r'^$', views.ProfileView), ]

Correct

urls.py

from django.conf.urls import url from mydemoapp import views urlpatterns = [ url(r'^$', views.ProfileView.as_view()), ]
Improve this answer
Sign up to request clarification or add additional context in comments.

2 Comments

3 Years later in Django 3.0 this bailed me out. I'm having troubles understanding why .as_view() is required. In my situation I'm using django rest, and I want an endpoint to run an internal operation, rather than just serve or modify data. The ModelViewSet does not require .as_view() to work, but APIView does. I'm assuming this is just abstraction setting a weird precedent?
@trevdev Because Django’s URL resolver expects to send the request and associated arguments to a callable function, not a class, class-based views have an as_view() class method which returns a function that can be called when a request arrives for a URL matching the associated pattern. For more details look here docs.djangoproject.com/en/3.1/topics/class-based-views/intro/…
4

You are using ViewSet urls wrong. This is right way

# project/urls.py from django.conf.urls import url, include from django.contrib import admin from rest_framework import routers from mydemoapp import views router = routers.DefaultRouter() router.register(r'demo', views.ProfileView) urlpatterns = [ url(r'^admin/', admin.site.urls), url(r'^', include(router.urls)), ]

Read more http://www.django-rest-framework.org/api-guide/routers/

Answering comment

Now i get AssertionError: base_name argument not specified, and could not automatically determine the name from the viewset, as it does not have a .queryset attribute.

Your view is incorrect as well. It should spicify queryset not profile

class ProfileView(viewsets.ModelViewSet): queryset = ProfileModel.objects.all() # <-- here serializer_class = ProfileSerializer
Improve this answer

Comments

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.