Validation-based caching in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the cache control header for 60 seconds.

Rest API

response.headers['Cache-Control'] = '[1]'

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

Amax-age=60

Bno-cache

Cno-store

Dprivate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'no-cache' disables caching instead of setting duration.

Using 'private' restricts caching to private caches only.

Setting Cache-Control to max-age=60 tells clients to cache the response for 60 seconds.

2fill in blank

medium

Complete the code to check if the ETag header matches the client's If-None-Match header.

Rest API

if request.headers.get('If-None-Match') == [1]:

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

Arequest.headers['ETag']

Bresponse.headers['ETag']

Cresponse.headers['Cache-Control']

Drequest.headers['Cache-Control']

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing with request headers instead of response headers.

Using Cache-Control header instead of ETag.

The server compares the client's If-None-Match header with the response's ETag to decide if content is unchanged.

3fill in blank

hard

Fix the error in setting the 304 Not Modified response status.

Rest API

if request.headers.get('If-None-Match') == response.headers.get('ETag'):
    return [1]

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

A500

B404

C200

D304

Attempts:

3 left

💡 Hint

Common Mistakes

Using 200 returns full content unnecessarily.

Using 404 or 500 are error codes, not cache-related.

HTTP status code 304 means Not Modified, telling the client to use cached content.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that caches only responses with status 200.

Rest API

cache = {url: response for url, response in responses.items() if response.status_code [1] [2]

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

A==

B!=

C200

D404

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' caches error responses.

Checking for 404 caches not found errors.

The comprehension keeps only responses where status_code == 200, meaning successful responses are cached.

5fill in blank

hard

Fill all three blanks to build a dictionary comprehension caching responses with ETag and max-age > 0.

Rest API

valid_cache = {url: resp for url, resp in responses.items() if resp.headers.get([1]) and int(resp.headers.get([2], 0)) [3] 0}

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

A'ETag'

B'Cache-Control'

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for Cache-Control in place of ETag.

Using '<' instead of '>' for max-age comparison.

This comprehension caches responses that have an ETag header and a Cache-Control max-age greater than zero.