Validation-based caching in Rest API - Mini Project: Build & Apply

Validation-based caching in a REST API

📖 Scenario: You are building a simple REST API that returns user profile data. To improve performance, you want to add validation-based caching. This means the API will store the last returned data and a validation token (like an ETag). When the client sends a request with the token, the API checks if the data has changed. If not, it returns a 304 Not Modified status instead of the full data.

🎯 Goal: Build a REST API endpoint that returns user data with validation-based caching using ETag headers.

📋 What You'll Learn

Create a dictionary called user_profile with exact keys and values

Create a variable called etag with the exact string value

Write a function called get_user_profile that takes a parameter client_etag and returns a tuple of (status_code, data_or_message)

Print the result of calling get_user_profile with client_etag set to the exact string "abc123"

💡 Why This Matters

🌍 Real World

Validation-based caching is used in web APIs to reduce data transfer and improve speed by sending data only when it changes.

💼 Career

Understanding caching and validation tokens like ETag is important for backend developers working on efficient REST APIs.

1

DATA SETUP: Create the user profile data

Create a dictionary called user_profile with these exact entries: 'id': 101, 'name': 'Alice', 'email': '[e-mail]'

Rest API

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

Need a hint?

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

2

CONFIGURATION: Create the ETag value

Create a variable called etag and set it to the string "abc123"

Rest API

user_profile = {'id': 101, 'name': 'Alice', 'email': '[e-mail]'}
# Create the etag variable with the string "abc123"
# Your code here

Need a hint?

Assign the string "abc123" to the variable etag.

3

CORE LOGIC: Write the get_user_profile function with validation-based caching

Write a function called get_user_profile that takes one parameter client_etag. Inside the function, if client_etag equals the variable etag, return the tuple (304, 'Not Modified'). Otherwise, return the tuple (200, user_profile).

Rest API

user_profile = {'id': 101, 'name': 'Alice', 'email': '[e-mail]'}
etag = "abc123"
# Define the get_user_profile function with client_etag parameter
# Your code here

Need a hint?

Use an if statement to compare client_etag and etag, then return the correct tuple.

4

OUTPUT: Call the function and print the result

Call the function get_user_profile with the argument "abc123" and print the result.

Rest API

user_profile = {'id': 101, 'name': 'Alice', 'email': '[e-mail]'}
etag = "abc123"

def get_user_profile(client_etag):
    if client_etag == etag:
        return (304, 'Not Modified')
    else:
        return (200, user_profile)

# Call get_user_profile with "abc123" and print the result
# Your code here

Need a hint?

Use print(get_user_profile("abc123")) to show the output.