Last-Modified and If-Modified-Since in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the Last-Modified header in the HTTP response.

Rest API

response.headers['Last-Modified'] = [1]

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

A'If-Modified-Since'

B'Wed, 21 Oct 2015 07:28:00 GMT'

C'200 OK'

D'Content-Type'

Attempts:

3 left

💡 Hint

Common Mistakes

Using header names instead of date strings.

Setting unrelated header values.

The Last-Modified header must be set to a valid HTTP date string indicating the last modification time of the resource.

2fill in blank

medium

Complete the code to read the If-Modified-Since header from the HTTP request.

Rest API

last_seen = request.headers.get([1])

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

A'Authorization'

B'Last-Modified'

C'Content-Length'

D'If-Modified-Since'

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing with Last-Modified header.

Using unrelated headers.

The If-Modified-Since header is sent by the client to tell the server the last time it saw the resource.

3fill in blank

hard

Fix the error in the code that compares If-Modified-Since with Last-Modified to decide if the resource is modified.

Rest API

if last_modified <= [1]:
    return 304

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

Alast_seen

Brequest.headers['If-Modified-Since']

CNone

Dresponse.headers['Last-Modified']

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing header strings directly without parsing.

Using wrong variables.

You must compare the stored last_modified date with the parsed last_seen date from the If-Modified-Since header.

4fill in blank

hard

Fill both blanks to parse the If-Modified-Since header and compare it with the last modified time.

Rest API

from datetime import datetime

client_time = datetime.strptime([1], '%a, %d %b %Y %H:%M:%S GMT')
if last_modified <= [2]:
    return 304

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

Alast_seen

Brequest.headers.get('If-Modified-Since')

Cclient_time

Dresponse.headers['Last-Modified']

Attempts:

3 left

💡 Hint

Common Mistakes

Parsing the wrong header.

Comparing string with datetime.

First, get the If-Modified-Since header string, then parse it into a datetime object, and finally compare with last_modified.

5fill in blank

hard

Fill all three blanks to set Last-Modified header, parse If-Modified-Since, and return 304 if not modified.

Rest API

from datetime import datetime

last_modified = datetime(2023, 6, 1, 12, 0, 0)
response.headers['Last-Modified'] = [1]
client_header = request.headers.get('If-Modified-Since')
client_time = datetime.strptime([2], '%a, %d %b %Y %H:%M:%S GMT') if client_header else None
if client_time and last_modified <= [3]:
    return 304

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

A'Thu, 01 Jun 2023 12:00:00 GMT'

Bclient_header

Cclient_time

D'Wed, 21 Oct 2015 07:28:00 GMT'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong date strings.

Not checking if client_header exists.

Comparing string with datetime.

Set the Last-Modified header to the correct date string, parse the If-Modified-Since header if present, and compare the datetime objects to decide if 304 should be returned.