class UserLoginSerializer(serializers.ModelSerializer):
    token = serializers.CharField(allow_blank=True, read_only=True)

    class Meta:
        model = User
        fields = [
            'username',
            'password',
            'token',
        ]
        extra_kwargs = {"password":
                            {"write_only": True}
                        }

    def validate(self, data):
        username = data.get('username', None)
        password = data.get('password', None)

        try:
            usern = Account.objects.get(username=username)
        except ObjectDoesNotExist:
            raise serializers.ValidationError("User does not exists")

        if usern.check_password(password):
            data["token"] = "asdasdasdasd"
        else:
            raise serializers.ValidationError("password invalid")

        return data

from django.conf.urls import url
from .views import AuthRegister, AuthLogin
from rest_framework_jwt.views import obtain_jwt_token

urlpatterns = [
    url(r'^register/$', AuthRegister.as_view()),
    url(r'^login/$', AuthLogin.as_view()),
    url(r'^api-token-auth/', obtain_jwt_token),
]