python redis celery启动失败

celery -A yourappname worker --loglevel=info
时候报错

File "/usr/local/lib/python3.7/site-packages/celery/backends/redis.py", line 22
from . import async, base
^
SyntaxError: invalid syntax

python（3.7）syntax成了关键字 redis 3.*不支持，需要升级redis包至4.*

升级命令如下

pip install --upgrade https://github.com/celery/celery/tarball/master

外网有时候下载安装失败，多试几次