Environment-based settings in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Django settings code snippet?

Given the following Django settings snippet that uses environment variables, what will be the value of DEBUG if the environment variable DJANGO_DEBUG is not set?

Django

import os

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

A False

B None

C Raises KeyError

D True

💡 Hint

Remember that os.getenv returns the default value if the environment variable is missing.

The os.getenv function returns the default string 'False' when DJANGO_DEBUG is not set. Comparing the string 'False' to 'True' results in False. So, DEBUG will be False.

📝 Syntax

intermediate

Which option correctly loads a secret key from environment variables in Django settings?

Select the option that correctly assigns the SECRET_KEY from an environment variable named DJANGO_SECRET_KEY and raises an error if it is missing.

A SECRET_KEY = os.environ.get('DJANGO_SECRET_KEY')

B SECRET_KEY = os.environ['DJANGO_SECRET_KEY']

C SECRET_KEY = os.getenv('DJANGO_SECRET_KEY', '')

D SECRET_KEY = os.getenv('DJANGO_SECRET_KEY') or raise ValueError('Missing key')

💡 Hint

Using os.environ with square brackets raises an error if the variable is missing.

Option B uses os.environ['DJANGO_SECRET_KEY'] which raises a KeyError if the environment variable is missing, ensuring the app fails fast. Option B and C do not raise errors if missing. Option B is invalid syntax in Python.

❓ state_output

advanced

What is the value of DATABASES['default']['PORT'] after running this Django settings code?

Consider this snippet in Django settings.py. What will be the port value used by the database configuration?

Django

import os

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': os.getenv('DB_NAME', 'mydb'),
        'USER': os.getenv('DB_USER', 'user'),
        'PASSWORD': os.getenv('DB_PASS', 'pass'),
        'HOST': os.getenv('DB_HOST', 'localhost'),
        'PORT': int(os.getenv('DB_PORT', '5432'))
    }
}

A 5432

B None

C Raises ValueError

D 0

💡 Hint

Check the default value and the type conversion used.

The environment variable DB_PORT is not set, so os.getenv('DB_PORT', '5432') returns the string '5432'. The int() function converts it to the integer 5432. So, PORT is 5432.

🔧 Debug

advanced

Which option causes a runtime error when loading environment-based settings?

Given this Django settings snippet, which option will cause a runtime error when the environment variable ALLOWED_HOSTS is not set?

Django

import os

ALLOWED_HOSTS = os.getenv('ALLOWED_HOSTS').split(',')

A ALLOWED_HOSTS = os.getenv('ALLOWED_HOSTS', '').split(',')

B ALLOWED_HOSTS = os.environ.get('ALLOWED_HOSTS').split(',') if os.environ.get('ALLOWED_HOSTS') else []

C ALLOWED_HOSTS = os.environ.get('ALLOWED_HOSTS', '').split(',')

D ALLOWED_HOSTS = os.getenv('ALLOWED_HOSTS').split(',')

💡 Hint

What happens if os.getenv returns None and you call split() on it?

Option D calls split() on None if ALLOWED_HOSTS is not set, causing an AttributeError. Other options provide a default empty string or check for None before splitting.

🧠 Conceptual

expert

Which approach best ensures secure environment-based settings in Django for production?

You want to keep sensitive settings like SECRET_KEY and database credentials secure and configurable per environment. Which approach below is the best practice?

A Store secrets in a JSON file committed to the repo and read it in settings.py

B Hardcode all secrets in settings.py and use gitignore to exclude it from version control

C Use environment variables and a secrets manager or vault in production, with .env files only for local development

D Use environment variables accessed via os.environ and load them with a .env file in development only

💡 Hint

Consider security and flexibility for different environments.

Option C is best practice: environment variables keep secrets out of code, and using a secrets manager or vault in production adds security. .env files are convenient for local development but should not be used in production.