Application factory pattern deep dive in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the Flask application factory function.

Flask

from flask import Flask

def create_app():
    app = Flask(__name__)
    return [1]

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

Acreate_app

BFlask

CNone

Dapp

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the Flask class instead of the app instance.

Not returning anything from the function.

The application factory function must return the Flask app instance it creates. Here, app is the Flask app object.

2fill in blank

medium

Complete the code to register a blueprint inside the application factory.

Flask

from flask import Flask, Blueprint

bp = Blueprint('main', __name__)

def create_app():
    app = Flask(__name__)
    app.[1](bp)
    return app

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

Aadd_blueprint

Bregister_blueprint

Cinclude_blueprint

Dattach_blueprint

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like add_blueprint.

Forgetting to register the blueprint.

Flask apps use register_blueprint() to add blueprints for modular routes.

3fill in blank

hard

Fix the error in the application factory by completing the missing configuration line.

Flask

def create_app():
    app = Flask(__name__)
    app.config['SECRET_KEY'] = [1]
    return app

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

A'mysecretkey'

BNone

C12345

DSECRET_KEY

Attempts:

3 left

💡 Hint

Common Mistakes

Setting SECRET_KEY to None or a variable name instead of a string.

Using an integer without quotes.

The SECRET_KEY must be a string used for security purposes. Here, a simple string is used.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps blueprint names to their URLs inside the factory.

Flask

def create_app():
    app = Flask(__name__)
    blueprints = {'main': '/main', 'admin': '/admin'}
    urls = [1]: [2] for [1] in blueprints
    return app

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

Aname

Burl

Cblueprints[name]

Dblueprints

Attempts:

3 left

💡 Hint

Common Mistakes

Using the dictionary name as the key or value directly.

Mixing up keys and values in the comprehension.

The comprehension iterates over blueprint names and maps each name to its URL from the dictionary.

5fill in blank

hard

Fill all three blanks to complete the factory pattern that initializes extensions and registers blueprints.

Flask

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

def create_app():
    app = Flask(__name__)
    app.config['SQLALCHEMY_DATABASE_URI'] = [1]
    db.[2](app)
    from .main import bp as main_bp
    app.[3](main_bp)
    return app

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

A'sqlite:///app.db'

Binit_app

Cregister_blueprint

D'postgresql://user@localhost/db'

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong method to initialize the extension.

Forgetting to register the blueprint.

Setting the database URI incorrectly.

The database URI is set to a SQLite file. The extension is initialized with init_app. The blueprint is registered with register_blueprint.