在django模型中保存处理过的数据？

from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=100)
    processed_data = models.CharField(max_length=100, blank=True)

    def save_processed_data(self):
        # 处理数据的逻辑
        processed_data = self.title.upper()
        self.processed_data = processed_data
        self.save()

from django.db import models
from django.db.models.signals import pre_save
from django.dispatch import receiver

class Book(models.Model):
    title = models.CharField(max_length=100)
    processed_data = models.CharField(max_length=100, blank=True)

@receiver(pre_save, sender=Book)
def process_data(sender, instance, **kwargs):
    instance.processed_data = instance.title.upper()