Environment variable management in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to load environment variables from a .env file using Flask.

Flask

from flask import Flask
from dotenv import [1]

app = Flask(__name__)

[1]()

Drag options to blanks, or click blank then click option'

Aload_env

Bload_dotenv

Cdotenv

Denv_load

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'dotenv()' instead of 'load_dotenv()'.

Trying to call a function that does not exist.

The load_dotenv() function loads environment variables from a .env file into the environment.

2fill in blank

medium

Complete the code to access the environment variable named 'SECRET_KEY' in Flask.

Flask

import os

secret_key = os.environ.get([1])

Drag options to blanks, or click blank then click option'

A'SECRET_KEY'

B'SECRETKEY'

C'KEY_SECRET'

D'SECRET'

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect variable names like 'SECRET' or 'KEY_SECRET'.

Forgetting to put the variable name in quotes.

Environment variables are accessed by their exact names as strings. Here, the variable is 'SECRET_KEY'.

3fill in blank

hard

Fix the error in the code to set a default value for an environment variable 'DATABASE_URL' if it is not set.

Flask

import os

database_url = os.environ.get('DATABASE_URL', [1])

Drag options to blanks, or click blank then click option'

A0

BNone

C''

D'sqlite:///default.db'

Attempts:

3 left

💡 Hint

Common Mistakes

Using None or empty string which may cause connection errors.

Using numeric zero which is not a valid URL.

Providing a default database URL string like 'sqlite:///default.db' ensures the app has a fallback connection string.

4fill in blank

hard

Fill both blanks to create a Flask config from environment variables with a fallback default.

Flask

app.config['DEBUG'] = os.environ.get([1], [2]) == 'True'

Drag options to blanks, or click blank then click option'

A'FLASK_DEBUG'

B'DEBUG'

C'False'

D'True'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'DEBUG' instead of 'FLASK_DEBUG' as environment variable name.

Using boolean False instead of string 'False' as default.

The environment variable 'FLASK_DEBUG' is checked, and if missing, defaults to 'False'. The comparison to string 'True' sets the boolean.

5fill in blank

hard

Fill all three blanks to create a dictionary of environment variables filtered by a prefix.

Flask

filtered_env = {k: v for k, v in os.environ.items() if k.startswith([1]) and v != [2] and len(v) > [3]

Drag options to blanks, or click blank then click option'

A'APP_'

B''

C0

D'ENV_'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong prefix like 'APP_'.

Comparing to None instead of empty string.

Using length check with wrong number.

This code filters environment variables starting with 'ENV_', excludes empty strings, and only includes values longer than 0 characters.