Extension initialization pattern in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Flask extension instance.

Flask

from flask_sqlalchemy import SQLAlchemy

db = [1]()

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

ASQLAlchemy

BFlask

CFlaskApp

DApp

Attempts:

3 left

💡 Hint

Common Mistakes

Using Flask instead of SQLAlchemy to create the extension instance.

Forgetting the parentheses to call the class.

The extension instance is created by calling SQLAlchemy().

2fill in blank

medium

Complete the code to initialize the extension with the Flask app.

Flask

from flask import Flask

app = Flask(__name__)
db = SQLAlchemy()
db.[1](app)

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

Arun_app

Binit_app

Cstart_app

Dcreate_app

Attempts:

3 left

💡 Hint

Common Mistakes

Using run_app or start_app which do not exist.

Trying to pass the app to the extension constructor instead of using init_app.

The init_app method initializes the extension with the Flask app.

3fill in blank

hard

Fix the error in the extension initialization pattern by completing the blank.

Flask

from flask import Flask
from flask_mail import Mail

mail = Mail()
app = Flask(__name__)
[1] = app
mail.init_app(app)

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Amail

Bmail_app

CMail

Dapp

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning the extension instance instead of the Flask app.

Using a variable name that is not defined.

The variable app should be assigned to itself or used directly; assigning app to app is correct here to avoid errors.

4fill in blank

hard

Fill both blanks to complete the factory function initializing the extension.

Flask

from flask import Flask
from flask_migrate import Migrate

migrate = Migrate()

def create_app():
    app = Flask(__name__)
    migrate.[1](app, [2])
    return app

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

Ainit_app

Bdb

Capp

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using start instead of init_app.

Passing the app twice or passing the wrong variable.

The Migrate extension is initialized with init_app passing the Flask app and the database instance db.

5fill in blank

hard

Fill all three blanks to complete the extension initialization with app factory pattern.

Flask

from flask import Flask
from flask_login import LoginManager

login_manager = LoginManager()

def create_app():
    app = Flask(__name__)
    login_manager.[1](app)
    login_manager.login_view = '[2]'
    login_manager.login_message_category = '[3]'
    return app

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

Ainit_app

Blogin

Cinfo

Dhome

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to call init_app.

Setting login_view to a wrong or non-existent route.

Using an incorrect message category.

The LoginManager is initialized with init_app. The login view is set to home and the message category to info for user feedback styling.