当Django只启动一次时执行代码？

# myapp/apps.py
from django.apps import AppConfig

class MyAppConfig(AppConfig):
    name = 'myapp'

    def ready(self):
        # 在这里放置你想在启动时执行的代码
        print("MyApp is ready!")

# myapp/__init__.py
default_app_config = 'myapp.apps.MyAppConfig'

# myapp/middleware.py
class StartupCodeMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response
        # 这里的代码会在服务器启动时执行一次
        print("Startup code executed!")

    def __call__(self, request):
        response = self.get_response(request)
        return response

# settings.py
MIDDLEWARE = [
    # ...
    'myapp.middleware.StartupCodeMiddleware',
    # ...
]