Python 3.7.5 : Set json with settings in Django project.

[mythcat@desk django]$ source env/bin/activate
(env) [mythcat@desk django]$ cd mysite/
(env) [mythcat@desk mysite]$ ls
db.sqlite3  manage.py  mysite  test001
(env) [mythcat@desk mysite]$ pwd
/home/mythcat/projects/django/mysite

Create a file named config.json in the folder django:

(env) [mythcat@desk mysite]$ vim /home/mythcat/projects/django/config.json

Open your settings.py file from your Django project and copy your secret key from this file to config.json, see:

{ 
  "SECRET_KEY":"your_secret_key_from_settings.py"
}

Change your settings.py file with these changes:

...
import json 
...
with open('/home/mythcat/projects/django/config.json') as config_file:
    config = json.load(config_file)
...
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = config['SECRET_KEY']

This allows us to get the SECRET_KEY from the config.json file.
We can add many variables into file config.json, like EMAIL_USER and EMAIL_PASS.
You need to have a validate JSON file and the settings.py will change from this:

EMAIL_HOST_USER = os.environ.get('EMAIL_USER')
...

to this source code for EMAIL_USER variable:

EMAIL_HOST_USER = config.get('EMAIL_USER')
...