title: Django REST Framework TypeError: register() missing 1 required positional argument: 'viewset'
body: <p>Im learning Django REST Framework and Im trying to get to work a simple ViewSet but I keep getting this error on the console when trying to run the server</p>
  
  <pre><code>  File "C:\Users\anahu\Projects\guatudu-api\api\api\locations\urls.py", line 13, in &lt;module&gt;
      router.register(r'countries', country_views.CountryViewSet, basename='country')
  TypeError: register() missing 1 required positional argument: 'viewset'
  </code></pre>
  
  <p>this is my app's urls.py</p>
  
  <pre><code>"""Locations Urls"""
  
  # Django
  from django.urls import path, include
  
  # Django Rest Framework
  from rest_framework.routers import DefaultRouter
  
  # Views
  from api.locations.views import countries as country_views
  
  router = DefaultRouter
  router.register(r'countries', country_views.CountryViewSet, basename='country')
  
  urlpatterns = router.urls
  </code></pre>
  
  <p>And this is my ViewSet</p>
  
  <pre><code>"""Countries view"""
  
  # Django REST Framework
  from rest_framework import viewsets
  
  # Serializers
  from api.locations.serializers import CountryModelSerializer
  
  # Models
  from api.locations.models import Country
  
  class CountryViewSet(viewsets.ModelViewSet):
      """Country viewset"""
  
      queryset = Country.objects.all()
      serializer_class = CountryModelSerializer
  </code></pre>
  
  <p>and this is my serializer</p>
  
  <pre><code>"""Country Serializers"""
  
  #Django Rest Framework
  from rest_framework import serializers
  from rest_framework.validators import UniqueValidator
  
  #Model
  from api.locations.models import Country
  
  class CountryModelSerializer(serializers.ModelSerializer):
      """Country Model Serializer"""
  
      class Meta:
          """Meta class"""
          model = Country
          fields = (
              'id',
              'name',
              'image'
          )
  </code></pre>
  
  <p>is pretty basic stuff, but I keep getting that error. All I can imagine is that for some reason Im not getting the ViewSet from on the urls.py correctly? I hope you guys can help me</p>