If-None-Match and 304 responses in Rest API - Mini Project: Build & Apply

Using If-None-Match Header and 304 Responses in REST API

📖 Scenario: You are building a simple REST API that returns user profile data. To save bandwidth and improve speed, you want to use the If-None-Match header and 304 Not Modified responses.This means the client sends a version tag (ETag) it has, and the server checks if the data has changed. If not, the server replies with 304 and no data, telling the client to use its cached copy.

🎯 Goal: Build a REST API endpoint that returns user data with an ETag. It should check the If-None-Match header from the client and respond with 304 Not Modified if the data has not changed, or 200 OK with the data if it has changed.

📋 What You'll Learn

Create a dictionary called user_profile with keys name, age, and email and exact values 'Alice', 30, and '[e-mail]' respectively.

Create a string variable called etag with the exact value "v1" representing the version of the data.

Write a function called handle_request that takes a parameter if_none_match (string or None). Inside, check if if_none_match equals etag. If yes, return a tuple (304, None). Otherwise, return (200, user_profile).

Call handle_request twice: once with if_none_match set to "v1" and once with None. Print the results exactly as shown.

💡 Why This Matters

🌍 Real World

Web servers use ETags and 304 responses to reduce bandwidth and speed up page loads by telling browsers when cached data is still valid.

💼 Career

Understanding HTTP caching headers like If-None-Match and 304 responses is important for backend developers building efficient REST APIs.

1

Create the user profile data

Create a dictionary called user_profile with these exact entries: 'name': 'Alice', 'age': 30, and 'email': '[e-mail]'.

Rest API

# Create the user_profile dictionary with name, age, and email
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with the exact keys and values.

2

Create the ETag version string

Create a string variable called etag and set it to the exact value "v1".

Rest API

user_profile = {'name': 'Alice', 'age': 30, 'email': '[e-mail]'}
# Create the etag string with value "v1"
# Your code here

Need a hint?

Use double quotes "v1" exactly for the etag string.

3

Write the request handler function

Write a function called handle_request that takes one parameter if_none_match. Inside, check if if_none_match == etag. If yes, return (304, None). Otherwise, return (200, user_profile).

Rest API

user_profile = {'name': 'Alice', 'age': 30, 'email': '[e-mail]'}
etag = "v1"
# Define handle_request(if_none_match) function
# Your code here

Need a hint?

Use an if-else statement to compare if_none_match with etag and return the correct tuple.

4

Call the function and print results

Call handle_request with if_none_match set to "v1" and print the result. Then call it with None and print the result.

Rest API

user_profile = {'name': 'Alice', 'age': 30, 'email': '[e-mail]'}
etag = "v1"

def handle_request(if_none_match):
    if if_none_match == etag:
        return (304, None)
    else:
        return (200, user_profile)

# Call handle_request with "v1" and print
# Call handle_request with None and print
# Your code here

Need a hint?

Use print() to show the results of calling handle_request with "v1" and None.