class User(AbstractUser):
    username = models.CharField(max_length=10, unique=True)
    email = models.EmailField(_('email address'), unique=True)
    USERNAME_FIELD = 'username'
    REQUIRED_FIELDS = ['email', 'first_name', 'last_name']

    def __str__(self):
        return "{}".format(self.email)

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ['url', 'email', 'username', 'first_name', 'last_name', 'password']
        extra_kwargs = {'password': {'write_only': True}}

        def create(self, validated_data):
            password = validated_data.pop('password')
            user = User(**validated_data)
            user.username = validated_data.get('username')
            user.set_password(password)
            user.save()
            return user