Page-based pagination in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the default page size to 10 in the API response.

Rest API

page_size = [1]

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

A10

B20

C5

D50

Attempts:

3 left

💡 Hint

Common Mistakes

Using too large or too small numbers for page size.

The default page size is set to 10 to limit the number of items returned per page.

2fill in blank

medium

Complete the code to extract the current page number from the request query parameters.

Rest API

current_page = request.args.get('[1]', 1, type=int)

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

Apage

Boffset

Csize

Dlimit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'limit' or 'offset' instead of 'page' for page number.

The 'page' parameter is commonly used to specify the current page number in pagination.

3fill in blank

hard

Fix the error in calculating the offset for the database query.

Rest API

offset = (current_page [1] 1) * page_size

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

A/

B-

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Adding 1 instead of subtracting 1 causes wrong offset.

Offset is calculated by subtracting 1 from the current page number, then multiplying by page size.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps each item id to its name for items on the current page.

Rest API

page_items = {item['[1]']: item['[2]'] for item in items}

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

Aid

Bname

Ctitle

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'title' or 'value' instead of 'name' for the value.

We use 'id' as the key and 'name' as the value to create the dictionary of items.

5fill in blank

hard

Fill all three blanks to filter items with price greater than 100 and create a dictionary with item names as keys and prices as values.

Rest API

filtered_items = {item['[1]']: item['[2]'] for item in items if item['[3]'] > 100}

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

Aname

Bprice

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'id' as key or filtering by wrong field.

We use 'name' as the key, 'price' as the value, and filter by 'price' greater than 100.

Practice

1. What is the main purpose of page-based pagination in REST APIs?

easy

A. To split large data into smaller pages for easier loading

B. To combine all data into one large response

C. To sort data alphabetically

D. To encrypt data before sending

Solution

1. Step 1: Understand pagination concept

   Pagination divides data into smaller parts called pages to avoid sending everything at once.

2. Step 2: Identify purpose in REST APIs

   Page-based pagination uses page number and limit to load data in chunks, improving performance and user experience.

3. Final Answer:

   To split large data into smaller pages for easier loading -> Option A

4. Quick Check:

   Pagination = split data into pages [OK]

Hint: Pagination means splitting data into pages [OK]

Common Mistakes:

• Thinking pagination sorts data
• Confusing pagination with encryption
• Assuming pagination combines all data

2. Which of the following is the correct way to request page 3 with 10 items per page using query parameters?

easy

A. /items?size=10&page=3

B. /items?limit=3&page=10

C. /items?page=10&limit=3

D. /items?page=3&limit=10

Solution

1. Step 1: Identify standard query parameters

   Page-based pagination commonly uses page for page number and limit for items per page.

2. Step 2: Match parameters to values

   Requesting page 3 with 10 items means page=3 and limit=10.

3. Final Answer:

   /items?page=3&limit=10 -> Option D

4. Quick Check:

   page=3 and limit=10 [OK]

Hint: Use page=number and limit=items per page [OK]

Common Mistakes:

• Swapping page and limit values
• Using wrong parameter names like size
• Mixing up page number with limit count

3. Given the API endpoint /products?page=2&limit=5 and a total of 12 products, how many products will be returned in the response?

medium

A. 2

B. 7

C. 5

D. 12

Solution

1. Step 1: Calculate items per page

   The limit is 5, so each page should have up to 5 products.

2. Step 2: Determine products on page 2

   Page 1 has products 1-5, page 2 has products 6-10, so page 2 returns 5 products.

3. Final Answer:

   5 -> Option C

4. Quick Check:

   limit = 5 products per page [OK]

Hint: Page 2 with limit 5 returns 5 items if available [OK]

Common Mistakes:

• Counting all 12 products instead of page limit
• Assuming leftover products on page 2
• Confusing page number with total items

4. You have this code snippet for pagination parameters:

page = int(request.GET.get('page', 1))
limit = int(request.GET.get('limit', 10))
start = (page - 1) * limit
end = page * limit
items = data[start:end]

What is the error if page is 0?

medium

A. It causes negative start index, returning wrong items

B. It returns the last page instead of first

C. It raises a syntax error

D. It ignores the limit parameter

Solution

1. Step 1: Calculate start index with page=0

   start = (0 - 1) * limit = -1 * limit = negative number.

2. Step 2: Understand slicing with negative start

   Negative start index in slicing returns items from the end, causing wrong data to be returned.

3. Final Answer:

   It causes negative start index, returning wrong items -> Option A

4. Quick Check:

   page=0 causes negative start index [OK]

Hint: Page must be >= 1 to avoid negative start index [OK]

Common Mistakes:

• Assuming page=0 is valid
• Expecting syntax error instead of logic error
• Ignoring negative slicing effects

5. You want to implement page-based pagination for an API returning 23 items with a limit of 7 per page. How many pages will the client need to request to get all items?

hard

A. 3

B. 4

C. 5

D. 7

Solution

1. Step 1: Calculate full pages

   Each page holds 7 items, so 3 full pages hold 21 items (3 * 7 = 21).

2. Step 2: Calculate remaining items

   23 total items - 21 = 2 items remain, needing one more page.

3. Step 3: Total pages needed

   3 full pages + 1 partial page = 4 pages total.

4. Final Answer:

   4 -> Option B

5. Quick Check:

   23 items / 7 per page = 4 pages [OK]

Hint: Divide total items by limit, round up for pages [OK]

Common Mistakes:

• Ignoring leftover items needing extra page
• Rounding down instead of up
• Assuming pages equal limit count