Cursor-based pagination in Rest API - Mini Project: Build & Apply

Cursor-based Pagination in a REST API

📖 Scenario: You are building a simple REST API that returns a list of products. To handle large lists efficiently, you want to implement cursor-based pagination. This means the API will return a limited number of products per request and a cursor to fetch the next set.

🎯 Goal: Build a REST API endpoint that returns products with cursor-based pagination. You will create the data, set a page size, implement the pagination logic, and finally output the paginated products along with the next cursor.

📋 What You'll Learn

Create a list of products with exact names and IDs

Set a page size variable to control how many products are returned per page

Implement cursor-based pagination logic using the product ID as the cursor

Output the current page of products and the next cursor value

💡 Why This Matters

🌍 Real World

Cursor-based pagination is used in APIs to efficiently load large lists of data in small chunks, improving speed and user experience.

💼 Career

Understanding cursor-based pagination is important for backend developers building scalable APIs and for frontend developers consuming paginated data.

1

Create the product list

Create a list called products containing these dictionaries exactly: {'id': 1, 'name': 'Apple'}, {'id': 2, 'name': 'Banana'}, {'id': 3, 'name': 'Cherry'}, {'id': 4, 'name': 'Date'}, {'id': 5, 'name': 'Elderberry'}

Rest API

# Create the list of products with exact IDs and names
# Your code here

Need a hint?

Use a list of dictionaries. Each dictionary must have keys 'id' and 'name' with the exact values.

2

Set the page size

Create a variable called page_size and set it to 2 to limit the number of products returned per page

Rest API

products = [
    {'id': 1, 'name': 'Apple'},
    {'id': 2, 'name': 'Banana'},
    {'id': 3, 'name': 'Cherry'},
    {'id': 4, 'name': 'Date'},
    {'id': 5, 'name': 'Elderberry'}
]
# Set the page size to 2
# Your code here

Need a hint?

Just create a variable named page_size and assign it the number 2.

3

Implement cursor-based pagination logic

Create a variable called cursor and set it to 0. Then create a list called page that contains products with id greater than cursor, limited to page_size items

Rest API

products = [
    {'id': 1, 'name': 'Apple'},
    {'id': 2, 'name': 'Banana'},
    {'id': 3, 'name': 'Cherry'},
    {'id': 4, 'name': 'Date'},
    {'id': 5, 'name': 'Elderberry'}
]
page_size = 2
# Set cursor to 0
# Create page list with products having id > cursor, limited to page_size
# Your code here

Need a hint?

Use a list comprehension to filter products with id greater than cursor and slice the list to page_size.

4

Output the paginated products and next cursor

Print the page list and then print the next_cursor which is the id of the last product in page if page is not empty, otherwise print null

Rest API

products = [
    {'id': 1, 'name': 'Apple'},
    {'id': 2, 'name': 'Banana'},
    {'id': 3, 'name': 'Cherry'},
    {'id': 4, 'name': 'Date'},
    {'id': 5, 'name': 'Elderberry'}
]
page_size = 2
cursor = 0
page = [product for product in products if product['id'] > cursor][:page_size]
# Print the page list
# Print the next_cursor value
# Your code here

Need a hint?

Print the page list first. Then find the last product's id in page for next_cursor. If page is empty, print null.