Ryu import error

[RanaZubair]

I have ubuntu 16.04 with virtualenv setup. When I try to run 12.py sample file ryu-manger giver following errors.

File "/home/user/ryu_project/bin/ryu-manager", line 5, in
from ryu.cmd.manager import main
File "/home/user/ryu_project/lib/python3.6/site-packages/ryu/cmd/manager.py", line 33, in
from ryu.app import wsgi
File "/home/zubair/projects/ryu2/lib/python3.6/site-packages/ryu/app/wsgi.py", line 109, in

I think I have import error for main and wsgi. How this problem will be resolved.

[JiasenLee]

I also met the same error recently. It seems like that you had installed the incompatible version of eventlet. I googled the error and the answer from stackoverflow may help you. Here is the question and answers Gunicorn ImportError: cannot import name 'ALREADY_HANDLED' from 'eventlet.wsgi' in docker