Teardown hooks in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to register a teardown function in Flask.

Flask

from flask import Flask
app = Flask(__name__)

@app.[1]()
def cleanup(exception=None):
    print("Cleaning up after request")

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

Abefore_request

Bteardown_request

Croute

Dafter_request

Attempts:

3 left

💡 Hint

Common Mistakes

Using @app.before_request instead of @app.teardown_request

Using @app.after_request which does not run on exceptions

The @app.teardown_request decorator registers a function to run after each request, even if an exception occurs.

2fill in blank

medium

Complete the code to access the exception object in a teardown function.

Flask

@app.teardown_request
def cleanup([1]=None):
    if [1]:
        print(f"Exception occurred: [1]")

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

Aexception=None

Bexception

Cexc

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Not providing a default value for the exception argument

Using a different argument name without default

The teardown function receives an optional exception argument which is None if no error occurred.

3fill in blank

hard

Fix the error in the teardown function registration.

Flask

def cleanup(exception=None):
    print("Cleaning up")

app.[1](cleanup)

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

Abefore_request

Bafter_request

Cteardown_request

Droute

Attempts:

3 left

💡 Hint

Common Mistakes

Using app.before_request(cleanup) instead

Using app.route(cleanup) which is for URL routes

To register a teardown function, use app.teardown_request decorator or call app.teardown_request(cleanup).

4fill in blank

hard

Fill both blanks to create a teardown function that closes a database connection.

Flask

@app.[1]()
def close_db([2]=None):
    db = getattr(g, 'db', None)
    if db is not None:
        db.close()

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

Ateardown_request

Bbefore_request

Cexception

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using before_request decorator

Using wrong argument name like error

The teardown function uses @app.teardown_request and receives an exception argument.

5fill in blank

hard

Fill all three blanks to register a teardown function that logs errors and cleans up resources.

Flask

@app.[1]()
def teardown([2]=None):
    if [2]:
        app.logger.error(f"Error: [2]")
    cleanup_resources()

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

Ateardown_request

Bexception

Dbefore_request

Attempts:

3 left

💡 Hint

Common Mistakes

Using before_request decorator

Not using the exception argument properly

The function is decorated with @app.teardown_request and uses the exception argument to check for errors.