Channels: AttributeError: 'NoneType' object has no attribute 'send' on Channels Documentation, Release 2.1.6

[mesutbicer]

Hello there. I'm working on the Channels library for the first time and testing the 2.1.6 version of your channels documentation (dated 09 December 2018).

However, even though I do all the steps step by step, I get the following error when I apply the following line on page 21.

mesut@ubuntu:~/Desktop/Django_Channels_Tutorial/mysite$ sudo python3 manage.py shell
[sudo] password for mesut: 
Python 3.6.7 (default, Oct 22 2018, 11:32:17) 
[GCC 8.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> import channels.layers
>>> channel_layer = channels.layers.get_channel_layer()
>>> from asgiref.sync import async_to_sync
>>> async_to_sync(channel_layer.send)('test_channel', {'type':'hello'})
Traceback (most recent call last):
  File "/usr/lib/python3.6/code.py", line 91, in runcode
    exec(code, self.locals)
  File "<console>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'send'
>>> type(channel_layer)
<class 'NoneType'>
>>> 

And my settings.py config related lines like that:

ASGI_APPLICATION = 'mysite.routing.application'
CHANNEL_LAYERS = {
          'default': {
                'BACKEND': 'channels_redis.core.RedisChannelLayer',
                'CONFIG': {
                         "hosts": [('127.0.0.1', 6379)],
                 },
           },
}

Why am I getting this error and how do I fix it?

Thank you in advance for those who will help.

• My test OS: Ubuntu 18.04.1 LTS

[mesutbicer]

I solved the problem. The problem is that the configuration of the CHANNEL_LAYERS configuration should not be saved even though settings.py was visible on the ubuntu virtual machine. I solved it by rebooting the virtual machine.

[DHUer]

I just have met that problems, your solution is right for me

[henrikstroem]

A good way to test for such issues:

from django.conf import settings
settings.CHANNEL_LAYERS

If you get "AttributeError: 'Settings' object has no attribute 'CHANNEL_LAYERS'" the system is not reading your settings file - or rather not up to date.