serializers.py 文件源码

def validate(self, data):
        # To handle cases creation, update and partial update
        pizza = data.get('pizza', getattr(self.instance, 'pizza', None))
        size = data.get('size', getattr(self.instance, 'size', None))
        if size not in pizza.sizes:
            raise serializers.ValidationError(_('You should provide valid size for your pizza'))
        return data