How to find django static files in production - css

Question

I am trying to get a django web site into production. The dev version works fine, but in production the application does not seem to find my css files.
I know that there are a lot of queries similar to mine and I have perused many and tried the suggested solutions.
The production version seems to work perfectly apart from the static files issue
In settings.py I have
DEBUG=False
and
STATIC_URL = '/static/'
STATIC_ROOT = os.path.join(BASE_DIR, 'static_files')
I have run
python manage.py collectstatic
and the css and js directories are copied correctly into my_app/static_files
I have restarted the server but it still does not function correctly.
My tree on the production server is:
.
├── my_app
│   ├── __init__.py
│   ├── settings.py
│   ├── static
│   │   ├── css
│   │   │   ├── main.css
│   │   └── js
│   ├── templates
│   │   ├── base.html
│   ├── urls.py
│   └── wsgi.py
├── boards
│   ├── admin.py
│   ├── apps.py
│   ├── __init__.py
│   ├── migrations
│   │   └── __init__.py
│   ├── models.py
│   ├── templates
│   │   └── boards
│   │   ├── about.html
│   │   ├── contact.html
│   ├── tests.py
│   ├── urls.py
│   └── views.py
├── manage.py
├── passenger_wsgi.py
├── static_files
│   ├── css
│   │   ├── main.css
│   └── js
├── _templates

Answer 1

Web servers handle this. What are you using as a server? For example, on Nginx we have paths for both static/media files.
server {
set $app_name 'APP_NAME';
set $root 'ROOT/$app_name';
listen 8000;
server_name 127.0.0.1;
location /static/ {
root $root/;
}
location /media/ {
root $root/attachments/;
}
location / {
include proxy_params;
proxy_pass http://unix:$root/$app_name.sock;
}
}

Answer 2

After hours of going through code line by line and inspired by an answer to this question I spotted this in wsgi.py (which didn't look right):
if settings.DEBUG:
application = StaticFilesHandler(get_wsgi_application())
else:
application = get_wsgi_application()
I have changed it to:
if settings.DEBUG:
application = get_wsgi_application()
else:
application = StaticFilesHandler(get_wsgi_application())
and now it finds the static files and works perfectly.