Laravel that I usually code has a command that updates the encryption key at .env file. To be honest, I love this approach and I wanted to replicate upon my django project.

Therefore, I followed these steps:

Step 1: Load `.env` file

See: https://dev.to/pcmagas/how-to-load-env-in-django-project-4c9d

Step 2: Use `SECRET_KEY` env file:

At settings.py Do:

SECRET_KEY = os.getenv('SECRET_KEY',None)

if SECRET_KEY is None:
    raise RuntimeError("SECRET_KEY value is not defined upon .env file")

Step 3 Create a command that update the `.env`:

I made the script myapp/management/commands/mk_key.py with the following (replace myapp with your own application name):

from django.core.management.base import BaseCommand
from django.core.management.utils import get_random_secret_key
import os

class Command(BaseCommand):
    help = 'Create a new Secret Key'

    def handle(self, *args, **kwargs):

        key = get_random_secret_key()
        env_file_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..',"..","..",'.env')
        self.updateDotenv(env_file_path,key)

    def updateDotenv(self,env_file_path,key):

        with open(env_file_path, 'r') as file:
            lines = file.readlines()

            # Update the SECRET_KEY line
        updated_lines = []

        for line in lines:
            if line.startswith('SECRET_KEY'):
                continue
            else:
                updated_lines.append(line)

        line = f"SECRET_KEY='{key}'\n"
        updated_lines.insert(0,line)  # Replace with new key

        # Write the updated lines back to the .env file
        with open(env_file_path, 'w') as file:
            file.writelines(updated_lines)

        # Output the new secret key
        self.stdout.write(f"Updated .env\n")

Then run it as: