当app/tasks.py导入模型时，芹菜击败周期性任务失败

Question

我的程序结构与芹菜django demo完全一样，工作正常。问题是，在我的demoapp/tasks.py模拟I输入触发

django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet. 

奇怪，至少可以说一个模型（from .models import Service）。时间表的整个要点是通过向api发送一个请求来更新数据库。取出导入声明并注释掉适当的代码后，任务按预期运行。这里是模型的代码，但无论模型有多少个字段都会出现错误，这使得我相信错误不是由于模型编程的方式。我在跟踪火车。

from django.db import models 

# Create your models here. 

class Service(models.Model): 
    id = models.TextField(primary_key=True) 
    scheduled = models.DateTimeField() 
    expected = models.DateTimeField(null=True, blank=True) # null means cancelled 
    service = models.TextField() 
    platform = models.TextField() 
    origin = models.TextField() 
    dest = models.TextField() 

编辑：这里是我的demoapp/tasks.py文件：

# Create your tasks here 
from __future__ import absolute_import, unicode_literals 
from celery import shared_task 
import requests 
from .models import Service 
from django.db import transaction 
import datetime 
import pytz 

def clean(entry): 
    def remove_location_lists(i): 
     """takes care of services with multiple origins or destinations, taking only the first of each.""" 
     if type(i["origin"]["location"]) is list: 
      i["origin"] = i["origin"]["location"][0]["locationName"] 
     else: 
      i["origin"] = i["origin"]["location"]["locationName"] 

     if type(i["dest"]["location"]) is list: 
      i["dest"] = i["dest"]["location"][0]["locationName"] 
     else: 
      i["dest"] = i["dest"]["location"]["locationName"] 

     return i 

    def parse_time(i): 
     """converts the raw time string to a datetime object, and includes some logic to manage crossing midnight.""" 
     if i["expected"] == "Cancelled": 
      i["service"] = "cancelled" 
      i["expected"] = None 
     elif i["expected"] == "Delayed": # blank 
      i["service"] = "delayed" 
      i["expected"] = None 
     else: 
      i["service"] = "ontime" 
      i["expected"] = pytz.utc.localize(datetime.datetime.strptime(i["scheduled"], '%H:%M')) 

     i["scheduled"] = pytz.utc.localize(datetime.datetime.strptime(i["scheduled"], '%H:%M')) 
     i["scheduled"] = i["scheduled"].replace(day=datetime.date.today().day, month=datetime.date.today().month, 
               year=datetime.date.today().year) 

     try: 
      i["expected"] = i["expected"].replace(day=datetime.date.today().day, month=datetime.date.today().month, 
                year=datetime.date.today().year) 

      # include day detection logic! 

     except Exception as inst: 
      pass 

     return i 

    entry = remove_location_lists(entry) 
    entry = parse_time(entry) 

    return entry 

@shared_task 
def get_trips(): 
    print("run task") 
    url = "http://www.southernrailway.com/ajax/departures/json/" 
    get = {'from': 'GTW', 'to': '', 'id': ''} 

    r = requests.post(url, get) 
    json = r.json() 

    unsaved = [] 

    for i in json["arrayServices"]: 
     entry = {'id': i["serviceID"], 
       'scheduled': i["std"], 
       'expected': i["etd"], 
       'service': i["service"], 
       'platform': i["platform"], 
       'origin': i["origin"], 
       'dest': i["destination"]} 

     entry = clean(entry) 

     entry = Service(id=entry['id'], scheduled=entry['scheduled'], expected=entry["expected"], 
         service=entry['service'], platform=entry['platform'], origin=entry['origin'], 
         dest=entry['dest']) 

     unsaved.append(entry) 

    with transaction.atomic(): 
     for i in unsaved: 
      i.save() 

而且，良好的措施，这里是我celery.py的内容：

from __future__ import absolute_import, unicode_literals 
import os 
from celery import Celery 
from shitternrailways.tasks import get_trips 

# set the default Django settings module for the 'celery' program. 
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'arlyon.settings') 

app = Celery('arlyon') 

# Using a string here means the worker don't have to serialize 
# the configuration object to child processes. 
# - namespace='CELERY' means all celery-related configuration keys 
# should have a `CELERY_` prefix. 
app.config_from_object('django.conf:settings', namespace='CELERY') 

@app.on_after_configure.connect 
def setup_periodic_tasks(sender, **kwargs): 
    sender.add_periodic_task(1, get_trips.s(), name="get trips") 

# Load task modules from all registered Django app configs. 
app.autodiscover_tasks() 

@app.task(bind=True) 
def debug_task(self): 
    print('Request: {0!r}'.format(self.request)) 

和终于完全回溯：

/Users/v/Documents/programming/venvs/arlyon/bin/python /Users/v/Documents/programming/arlyon/manage.py runserver 8000 
Traceback (most recent call last): 
    File "/Users/v/Documents/programming/arlyon/manage.py", line 22, in <module> 
    execute_from_command_line(sys.argv) 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line 
    utility.execute() 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/core/management/__init__.py", line 302, in execute 
    settings.INSTALLED_APPS 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/conf/__init__.py", line 55, in __getattr__ 
    self._setup(name) 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/conf/__init__.py", line 43, in _setup 
    self._wrapped = Settings(settings_module) 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/conf/__init__.py", line 99, in __init__ 
    mod = importlib.import_module(self.SETTINGS_MODULE) 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/importlib/__init__.py", line 126, in import_module 
    return _bootstrap._gcd_import(name[level:], package, level) 
    File "<frozen importlib._bootstrap>", line 986, in _gcd_import 
    File "<frozen importlib._bootstrap>", line 969, in _find_and_load 
    File "<frozen importlib._bootstrap>", line 944, in _find_and_load_unlocked 
    File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed 
    File "<frozen importlib._bootstrap>", line 986, in _gcd_import 
    File "<frozen importlib._bootstrap>", line 969, in _find_and_load 
    File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked 
    File "<frozen importlib._bootstrap>", line 673, in _load_unlocked 
    File "<frozen importlib._bootstrap_external>", line 665, in exec_module 
    File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed 
    File "/Users/v/Documents/programming/arlyon/arlyon/__init__.py", line 5, in <module> 
    from .celery import app as celery_app 
    File "/Users/v/Documents/programming/arlyon/arlyon/celery.py", line 4, in <module> 
    from shitternrailways.tasks import get_trips 
    File "/Users/v/Documents/programming/arlyon/shitternrailways/tasks.py", line 5, in <module> 
    from .models import Service 
    File "/Users/v/Documents/programming/arlyon/shitternrailways/models.py", line 5, in <module> 
    class Service(models.Model): 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/db/models/base.py", line 94, in __new__ 
    app_config = apps.get_containing_app_config(module) 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/apps/registry.py", line 239, in get_containing_app_config 
    self.check_apps_ready() 
    File "/Users/v/Documents/programming/venvs/arlyon/lib/python3.5/site-packages/django/apps/registry.py", line 124, in check_apps_ready 
    raise AppRegistryNotReady("Apps aren't loaded yet.") 
django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet. 

Process finished with exit code 1 

A在寻找帮助的过程中，可能归因于年轻的芹菜4。所以我转向了你们。感谢您提供的任何提示。

Answer 1

您正在使用@shared_task修饰器来完成任务。这意味着该任务不附加到任何应用程序。但是，在celery.py中，您正尝试将这个任务用于节拍调度程序，并且会引发错误。

我看到两种可能的解决方法。首先，您可以将此任务从demoapp移动到celery.py中，并使用它与@ app.task修饰器一起使用。

其次，您可以尝试从应用程序访问任务。为此，您调用了app.autodiscover_tasks（）。这意味着任务被加载到应用程序中。所以你可以尝试：

@app.on_after_configure.connect 
def setup_periodic_tasks(sender, **kwargs): 
    sender.add_periodic_task(1, app.tasks["demoapp.get_trips"], name="get trips") 

然而它需要测试。我没有在我的机器上尝试它。祝你好运！