在Django中自动更改值

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

from django.db import models

class YourModel(models.Model):
    your_field = models.CharField(max_length=100)
    # 其他字段...

@receiver(pre_save, sender=YourModel)
def your_model_pre_save(sender, instance, **kwargs):
    # 自动更改字段的逻辑
    instance.your_field = '新值'

from django.apps import AppConfig

class YourAppConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'your_app_name'
    
    def ready(self):
        import your_app_name.signals  # 信号接收器所在的文件

default_app_config = 'your_app_name.apps.YourAppConfig'

your_model_instance = YourModel.objects.get(id=1)
print(your_model_instance.your_field)  # 输出：'新值'