django DEBUG=False still runs in debug mode

Question

I'm having issues setting my DEBUG = False on my deployed server (on heroku).

I don't believe I've seen this before, but setting debug to false is not getting rid of debug mode for my project. This means that when there are 500 errors it shows the error, and 404 errors are showing all my urls.

What's strange is that when i log into the server and run get the setting value from django.conf import settings settings.DEBUG it shows as False, which is what I set it to for the production server. TEMPLATE_DEBUG is also set to False.

I don't know I've ever seen this before where DEBUG = False but it's still acting in debug mode. Any ideas?

EDIT:

Thought I'd put this little note too because it's very common for people to be getting 500 or 400 errors when switching debug to False. I am not getting any errors, my project is just acting like it's in DEBUG mode.

# settings/dev.py
from .base import *

DEBUG = True
TEMPLATE_DEBUG = DEBUG

if not DEBUG:
    ALLOWED_HOSTS = ['localhost']

SECRET_KEY = 'localsecret1234123412341234'


# settings/prod.py
from .base import *

import dj_database_url, os

DEBUG = os.environ.get("DEBUG", False)
TEMPLATE_DEBUG = DEBUG

ALLOWED_HOSTS = ['mydomain.com']
SECRET_KEY = os.environ["DJANGO_SECRET_KEY"]

STATICFILES_STORAGE = 'whitenoise.django.GzipManifestStaticFilesStorage'
STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')

DATABASES = {}
DATABASES['default'] =  dj_database_url.config()

Answer 1

The root cause of issue - False translated to 'False' string not bool.

Used next solution (settings.py):

DEBUG = os.getenv('DEBUG', False) == 'True'

i.e.: in this case DEBUG will set to (bool) True, only if the environment variable is explicitly set to True or 'True'.

Good luck configuring! :)

Answer 2

DEBUG takes Boolean value.

The os.environ.get("DEBUG", False) returns string value.

All the string value while typecasting return True. That's why the DEBUG is True.

 print(bool(os.environ.get("DEBUG", False))) # output: True
 print(bool("False"))  # output: True
 print(bool(""))  # output: False

To solve issue in heroku don't set any value to config var. it will return null string and after typecasting it will return False: