如何在django中创建日志数据库来记录创建、更新或删除对象的用户？

from django.db import models
from django.contrib.auth.models import User

class Log(models.Model):
    ACTION_CHOICES = (
        ('C', '创建'),
        ('U', '更新'),
        ('D', '删除'),
    )
    action = models.CharField(max_length=1, choices=ACTION_CHOICES)
    timestamp = models.DateTimeField(auto_now_add=True)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    object_name = models.CharField(max_length=255)

from django.db.models.signals import post_save, pre_delete
from django.dispatch import receiver
from django.contrib.auth.models import User

@receiver(post_save)
def log_object_creation_update(sender, instance, created, **kwargs):
    if created:
        action = 'C'
    else:
        action = 'U'
    Log.objects.create(action=action, user=User.objects.get(username='当前用户'), object_name=sender.__name__)

@receiver(pre_delete)
def log_object_deletion(sender, instance, **kwargs):
    Log.objects.create(action='D', user=User.objects.get(username='当前用户'), object_name=sender.__name__)

from django.apps import AppConfig

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

    def ready(self):
        import myapp.signals  # 导入信号处理器模块

python manage.py makemigrations
python manage.py migrate