啟動celery后執行任務報錯：django.core.exceptions.ImproperlyConfigured

工作的環境版本如下：

【Django version】: 2.1

【celery version】：4.4.0rc2

【python version】: 3.7

【Redis version】：3.2.1

啟動celery沒有報錯，但是執行隊列任務的時候就爆出下的錯誤：

[2019-07-07 18:43:27,756: INFO/MainProcess] Connected to redis://127.0.0.1:6379/0
[2019-07-07 18:43:27,764: INFO/MainProcess] mingle: searching for neighbors
[2019-07-07 18:43:28,784: INFO/MainProcess] mingle: all alone
[2019-07-07 18:43:28,818: INFO/MainProcess] celery@DESKTOP-9T9MK4N ready.
[2019-07-07 18:43:28,818: INFO/MainProcess] pidbox: Connected to redis://127.0.0.1:6379/0.
[2019-07-07 18:43:40,217: INFO/MainProcess] Received task: celery_tasks.tasks.send_register_active_email[c4156f7a-ea3d-457d-8b18-40cc93bb718c]
[2019-07-07 18:43:40,219: ERROR/MainProcess] Task celery_tasks.tasks.send_register_active_email[c4156f7a-ea3d-457d-8b18-40cc93bb718c] raised unexpected: ImproperlyConfi
gured('Requested setting EMAIL_FROM, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure(
) before accessing settings.')
Traceback (most recent call last):
  File "c:\users\circle\appdata\local\programs\python\python37-32\lib\site-packages\celery\app\trace.py", line 385, in trace_task
    R = retval = fun(*args, **kwargs)
  File "c:\users\circle\appdata\local\programs\python\python37-32\lib\site-packages\celery\app\trace.py", line 650, in __protected_call__
    return self.run(*args, **kwargs)
  File "C:\Users\Circle\Desktop\circle\dailyfresh\celery_tasks\tasks.py", line 25, in send_register_active_email
    sender = settings.EMAIL_FROM
  File "c:\users\circle\appdata\local\programs\python\python37-32\lib\site-packages\django\conf\__init__.py", line 57, in __getattr__
    self._setup(name)
  File "c:\users\circle\appdata\local\programs\python\python37-32\lib\site-packages\django\conf\__init__.py", line 42, in _setup
    % (desc, ENVIRONMENT_VARIABLE))
django.core.exceptions.ImproperlyConfigured: Requested setting EMAIL_FROM, but settings are not configured. You must either define the environment variable DJANGO_SETTI
NGS_MODULE or call settings.configure() before accessing settings.

大概意思就是沒有配置設置。您必須定義環境變量DJANGO_SETTINGS_MODULE在訪問設置之前調用settings.configure()。

解決辦法就是：

# 使用celery，首先導入進來
from celery import Celery
from django.conf import settings
from django.core.mail import send_mail

# 下面就是解決辦法：將Django中的配置信息先導入進來
import os
import django
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'dailyfresh.settings')
django.setup()

# 創建一個Celery類的實例對象
app = Celery('celery_tasks.tasks', broker='redis://127.0.0.1:6379/0') 


# 定義任務函數
@app.task
def send_register_active_email(email, username, token):
    """發送激活郵件"""
    subject = '歡迎觀看本篇文章'
    message = '希望對你有幫助'
    sender = settings.EMAIL_FROM
    recipient_list = [email]
    html_message = '<h1>The End</h1>'
    send_mail(subject, message, sender, recipient_list, html_message=html_message)