django-rest-framework 에서의 password2 처리

gistfile1.py

from django.contrib.auth.models import User
from rest_framework import serializers

class UserSerializer(serializers.ModelSerializer):
    password2 = serializers.CharField()

    def validate_password2(self, attrs, source):
        password2 = attrs.pop(source)
        if attrs['password'] != password2:
            raise serializers.ValidationError('password mismatch')
        return attrs

    def to_native(self, obj):
        self.fields.pop('password2')
        return super(UserSerializer, self).to_native(obj)

    class Meta:
        model = User

KeyError password2