Why background processing matters in Flask - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Flask class from the flask package.

Flask

from flask import [1]
app = [1](__name__)

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

AFlask

BRequest

Crender_template

Dredirect

Attempts:

3 left

💡 Hint

Common Mistakes

Using Request instead of Flask

Trying to import render_template here

Using redirect which is for routing

The Flask class is imported to create the app instance.

2fill in blank

medium

Complete the code to define a route that returns 'Hello World!'.

Flask

@app.route('/')
def home():
    return [1]

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

AHello World!

B'Hello World!'

Crender_template('index.html')

Dredirect('/')

Attempts:

3 left

💡 Hint

Common Mistakes

Returning unquoted text causing NameError

Using render_template without a template file

Using redirect which sends a new request

The return value must be a string, so it needs quotes.

3fill in blank

hard

Fix the error in the code to run the Flask app only when the script is executed directly.

Flask

if __name__ == [1]:
    app.run(debug=True)

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

A'main'

B__main__

C'__main__'

D__name__

Attempts:

3 left

💡 Hint

Common Mistakes

Using __main__ without quotes causes NameError

Using 'main' misses the underscores

Comparing to __name__ itself is always True

The special variable __name__ is compared to the string '__main__' to check if the script runs directly.

4fill in blank

hard

Fill both blanks to create a background task using threading to avoid blocking the main Flask app.

Flask

import threading

def background_task():
    print('Task running')

thread = threading.Thread(target=[1])
thread.[2]()

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

Abackground_task

Bstart

Crun

Djoin

Attempts:

3 left

💡 Hint

Common Mistakes

Calling the function instead of passing it as target

Using run() which runs in the current thread

Using join() which waits for thread to finish

The thread needs the function as target and start() to run in background.

5fill in blank

hard

Fill all three blanks to create a Flask route that starts a background task and immediately returns a response.

Flask

@app.route('/start-task')
def start_task():
    thread = threading.Thread(target=[1])
    thread.[2]()
    return [3]

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

Abackground_task

Bstart

C'Task started!'

Djoin

Attempts:

3 left

💡 Hint

Common Mistakes

Using join() which blocks the response

Calling the function instead of passing it as target

Returning without quotes causing errors

The route starts the background task and returns a quick message without waiting.