Pagination with limit and offset in Rest API - Mini Project: Build & Apply

Pagination with limit and offset

📖 Scenario: You are building a simple REST API that returns a list of products. To avoid sending too many products at once, you want to add pagination using limit and offset parameters.

🎯 Goal: Create a REST API endpoint that returns a paginated list of products using limit and offset query parameters.

📋 What You'll Learn

Create a list called products with 10 product names.

Create variables limit and offset to control pagination.

Use limit and offset to slice the products list.

Print the paginated list of products.

💡 Why This Matters

🌍 Real World

Pagination is used in APIs to send data in small chunks so users can load pages quickly without waiting for all data at once.

💼 Career

Understanding pagination is important for backend developers and API designers to improve performance and user experience.

1

Create the product list

Create a list called products with these exact product names: 'Apple', 'Banana', 'Carrot', 'Dates', 'Eggplant', 'Fig', 'Grapes', 'Honeydew', 'Iceberg', 'Jackfruit'.

Rest API

# Create the list called products with the exact names
# Your code here

Hint

Use square brackets [] to create a list and separate items with commas.

2

Set limit and offset variables

Create two variables: limit set to 3 and offset set to 4.

Rest API

products = ['Apple', 'Banana', 'Carrot', 'Dates', 'Eggplant', 'Fig', 'Grapes', 'Honeydew', 'Iceberg', 'Jackfruit']
# Create limit and offset variables
# Your code here

Hint

Use simple assignment like limit = 3 and offset = 4.

3

Slice the products list using limit and offset

Create a new list called paginated_products that contains products starting from offset and includes limit number of products using list slicing.

Rest API

products = ['Apple', 'Banana', 'Carrot', 'Dates', 'Eggplant', 'Fig', 'Grapes', 'Honeydew', 'Iceberg', 'Jackfruit']
limit = 3
offset = 4
# Create paginated_products using slicing
# Your code here

Hint

Use products[offset:offset+limit] to get the slice.

4

Print the paginated products

Print the paginated_products list to show the paginated result.

Rest API

products = ['Apple', 'Banana', 'Carrot', 'Dates', 'Eggplant', 'Fig', 'Grapes', 'Honeydew', 'Iceberg', 'Jackfruit']
limit = 3
offset = 4
paginated_products = products[offset:offset+limit]
# Print the paginated_products list
# Your code here

Hint

Use print(paginated_products) to display the list.

Practice

1.

What does the limit parameter control in pagination?

easy

A. The starting position of items to return

B. The sorting order of the items

C. The total number of items in the database

D. The number of items to return in one page

Solution

1. Step 1: Understand the role of limit

   The limit parameter sets how many items you want to get back in one page of results.

2. Step 2: Differentiate from offset

   The offset controls where to start, not how many items to return.

3. Final Answer:

   The number of items to return in one page -> Option D

4. Quick Check:

   limit = number of items per page [OK]

Hint: Limit sets count of items per page, offset sets start point [OK]

Common Mistakes:

• Confusing limit with offset
• Thinking limit controls sorting
• Assuming limit is total items

2.

Which of the following is the correct way to request the second page of results with 10 items per page using limit and offset?

GET /items?limit=10&offset=?

easy

A. 10

B. 20

C. 0

D. 1

Solution

1. Step 1: Calculate offset for second page

   For page 1, offset is 0. For page 2, offset = limit * (page_number - 1) = 10 * (2 - 1) = 10.

2. Step 2: Confirm limit remains 10

   Limit stays 10 to get 10 items per page.

3. Final Answer:

   10 -> Option A

4. Quick Check:

   offset = limit * (page - 1) = 10 [OK]

Hint: Offset = limit x (page number - 1) [OK]

Common Mistakes:

• Using offset = page number
• Using offset = limit x page number
• Setting offset to 0 for second page

3.

Given the following API call, what items will be returned if the full list is ["a", "b", "c", "d", "e", "f"]?

GET /items?limit=2&offset=3

medium

A. ["d", "e"]

B. ["c", "d"]

C. ["a", "b"]

D. ["e", "f"]

Solution

1. Step 1: Understand offset and limit

   Offset 3 means start from the 4th item (0-based index), which is "d".

2. Step 2: Select 2 items from offset

   Limit 2 means take 2 items starting at "d", so items are "d" and "e".

3. Final Answer:

   ["d", "e"] -> Option A

4. Quick Check:

   Start at index 3, take 2 items = ["d", "e"] [OK]

Hint: Offset is start index, limit is count from there [OK]

Common Mistakes:

• Starting count at 1 instead of 0
• Taking wrong slice of items
• Confusing offset and limit roles

4.

Identify the error in this API call for pagination: GET /items?limit=5&offset=-10

medium

A. Offset should be a string

B. Limit cannot be 5

C. Negative offset is invalid

D. Limit must be greater than offset

Solution

1. Step 1: Check offset value

   Offset represents the starting position and cannot be negative because you cannot start before the first item.

2. Step 2: Validate limit and offset rules

   Limit can be any positive number; offset must be zero or positive.

3. Final Answer:

   Negative offset is invalid -> Option C

4. Quick Check:

   Offset ≥ 0 required [OK]

Hint: Offset must never be negative [OK]

Common Mistakes:

• Allowing negative offset
• Confusing limit and offset roles
• Assuming offset can be string

5.

You have 53 items and want to paginate with limit=10. How many pages will you have, and what is the offset for the last page?

hard

A. 5 pages, offset 40

B. 6 pages, offset 50

C. 6 pages, offset 45

D. 7 pages, offset 60

Solution

1. Step 1: Calculate total pages

   Total pages = ceiling of total items / limit = ceil(53 / 10) = 6 pages.

2. Step 2: Calculate offset for last page

   Offset for last page = limit x (pages - 1) = 10 x (6 - 1) = 50.

3. Final Answer:

   6 pages, offset 50 -> Option B

4. Quick Check:

   Pages = 6, offset last = 50 [OK]

Hint: Pages = ceil(total/limit), offset = limit x (pages-1) [OK]

Common Mistakes:

• Using floor instead of ceiling for pages
• Calculating offset as limit x pages
• Ignoring leftover items on last page