password = serializers.CharField(max_length=20, write_only=True)


email = serializers.EmailField()
first_name = serializers.CharField(max_length=30)
last_name = serializers.CharField(max_length=30)

class Meta:
    model = User

    fields = ('url', 'id', 'first_name', 'last_name', 'email', 'password')

def validate_email(self, value):
    from validate_email_address import validate_email
    if User.all_objects.filter(email=value.lower()).exists():
        raise serializers.ValidationError('User with this email already exists.')

    return value.lower()

def create(self, validated_data):
    password = validated_data.pop('password')
    email = validated_data.pop('email')
    user = User.objects.create(
        username=email.lower(),
        email=email.lower(),
        role_id=1,
        **validated_data)
    user.set_password(password)

    user.save()

    return user