我一直在到处找，我找不到任何关于这个的参考，我的Django模型信号只在debug=True时工作，但如果debug=False则不起作用，这在本地主机和生产服务器上都发生。
我的设置是这样的:
settings.py
from pathlib import Path
import os
import environ
env = environ.Env()
environ.Env.read_env()
BASE_DIR = Path(__file__).resolve().parent.parent
#production
STATIC_ROOT = 'https://d1u356tnw52tcs.cloudfront.net/'
SECRET_KEY = env("SECRET_KEY_PROD")
DEBUG = True
ALLOWED_HOSTS = ['*']
CORS_ORIGIN_ALLOW_ALL = True
CORS_ORIGIN_WHITELIST = (
)
# Application definition
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'rest_framework',
'django.contrib.postgres',
'sellrapp',
'stock_management',
'corsheaders',
'drf_yasg',
'optimized_image',
'csvexport',
'kronos',
]
MIDDLEWARE = [
'django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'corsheaders.middleware.CorsMiddleware'
]
ROOT_URLCONF = '****.urls'
WSGI_APPLICATION = '****.wsgi.application'
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': env("NAME_PROD"),
'USER': env("USER_PROD"),
'PASSWORD': env("PASSWORD_PROD"),
'HOST': env("HOST_PROD"),
'PORT': env("PORT_PROD"),
}
}
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'Asia/Singapore'
USE_I18N = True
USE_L10N = True
USE_TZ = True
WEB_BASE_URL = 'https://****.com/'
BASE_URL_LIVE_CAMPAIGN = WEB_BASE_URL + "product/"
如果设置为debug=False，则不会触发信号，也不会产生任何错误。
signals.py
from django.dispatch import receiver
from django.db.models.signals import pre_save, post_save, pre_delete
from .models import ManualWithdrawals
@receiver(pre_delete, sender=ManualWithdrawals)
def manual_wd(sender, instance, **kwargs):
order = ManualWithdrawals.objects.get(id=instance.id)
consumer_order = order.order_id_list.all()
sample_order = order.sample_order_id_list.all()
total = str(instance.total_withdrawals).replace(".", "")
total = int(total)
if instance.order_id_list:
for order in consumer_order:
if instance.type == "reseller" and order.reseller_commission_status != "paid":
order.reseller_commission_status = "ready for collection"
order.save()
if instance.type == "merchant" and order.merchant_commission_status != "paid":
order.merchant_commission_status = "ready for collection"
order.save()
# updating sample order if any
if instance.sample_order_id_list:
for order in sample_order:
if instance.type == "merchant" and order.merchant_commission_status != "paid":
order.merchant_commission_status = "ready for collection"
order.save()
这对我有用:
当调用connect()或@receiver信号时，Pass weak=False
Django信号提到警告:
还要注意Django默认将信号处理程序存储为弱引用，所以如果你的处理程序是一个局部函数，它可能会被垃圾收集。为了防止这种情况，在调用信号的connect()时传递weak=False。
因此，有可能您的接收函数正在被垃圾收集。
例如:@receiver(pre_delete, sender=ManualWithdrawals, weak=False)
只是为了给@kaustubh-trivei的答案添加更多的见解。
当处理程序以这种方式注册时:
from django.db.models.signals import post_save
def create_and_register_handler(model):
def handler(sender, instance=None, created=False, **kwargs):
...
post_save.connect(handler, sender=model)
则weak=False是强制性的，否则它会被垃圾收集并立即注销。
由于实现细节的原因，当settings.DEBUG是True时，Django会创建一个额外的对处理程序的引用，以防止处理程序被垃圾收集和未注册。
实现细节:当settings.DEBUG为True时，处理程序的参数由django.utils.inspect模块验证，该模块内部使用functools.lru_cache()装饰器，这导致处理程序作为键存储在lru缓存字典中。
我们得到了相同的错误，这是因为对2个信号使用相同的函数名。
@reciever(....)
def set_something(...):
pass
@reciever(...)
def set_something(...): # This function name is the same as above
pass
事实证明，当我更新到新版本的psycopg时，问题发生了，不知何故，在更新我的psycopg到最新版本后，现在它工作得很好。