当django中的另一个字段发生变化时，如何切换布尔值字段？

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

from django.db import models

class MyModel(models.Model):
    field1 = models.BooleanField(default=False)
    field2 = models.CharField(max_length=100)

@receiver(pre_save, sender=MyModel)
def switch_boolean_field(sender, instance, **kwargs):
    if instance.field2 == 'some_value':
        instance.field1 = not instance.field1

from django.apps import AppConfig

class MyAppConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'myapp'

    def ready(self):
        import myapp.signals

INSTALLED_APPS = [
    ...
    'myapp.apps.MyAppConfig',
    ...
]