Bulk import and export in Rest API - Mini Project: Build & Apply

Bulk Import and Export with REST API

📖 Scenario: You work for a company that manages a list of products. You need to create a simple REST API to handle bulk import and export of product data in JSON format.This will help the company quickly add many products at once and also download all products easily.

🎯 Goal: Build a REST API with two endpoints:/import to accept a bulk list of products and store them./export to return all stored products as JSON.You will create the data storage, configure the API, write the core logic for import and export, and finally test the output.

📋 What You'll Learn

Create an in-memory list called products to store product dictionaries

Create a configuration variable max_import_size to limit bulk import size

Write a POST endpoint /import that accepts JSON list of products and adds them to products if size is within max_import_size

Write a GET endpoint /export that returns all stored products as JSON

💡 Why This Matters

🌍 Real World

Bulk import and export APIs are common in inventory management, e-commerce, and data migration tasks where many items need to be added or retrieved efficiently.

💼 Career

Understanding how to build bulk data endpoints is valuable for backend developers working with REST APIs, enabling efficient data handling and integration with other systems.

1

Create the initial data storage

Create an empty list called products to store product dictionaries.

Rest API

# Create an empty list called products
# Your code here

Hint

Use a list to hold multiple product items.

2

Add a configuration variable

Create a variable called max_import_size and set it to 5 to limit the number of products imported at once.

Rest API

products = []
# Create max_import_size variable and set it to 5
# Your code here

Hint

This variable will help control how many products can be imported in one request.

3

Write the bulk import endpoint

Using Flask, create a POST endpoint /import that reads a JSON list of products from the request body. If the list length is less than or equal to max_import_size, add all products to the products list and return JSON {"status": "success"}. Otherwise, return JSON {"status": "error", "message": "Too many products"} with status code 400.

Rest API

products = []
max_import_size = 5

from flask import Flask, request, jsonify
app = Flask(__name__)

# Create POST /import endpoint
# Your code here

Hint

Use request.get_json() to get the JSON data sent by the client.

Check the length of the list before adding.

4

Write the bulk export endpoint and test output

Create a GET endpoint /export that returns all products stored in the products list as JSON. Then, print the output of calling app.test_client().get('/export').get_json() to show the exported products.

Rest API

products = []
max_import_size = 5

from flask import Flask, request, jsonify
app = Flask(__name__)

@app.route('/import', methods=['POST'])
def import_products():
    new_products = request.get_json()
    if not isinstance(new_products, list):
        return jsonify({"status": "error", "message": "Invalid data format"}), 400
    if len(new_products) <= max_import_size:
        products.extend(new_products)
        return jsonify({"status": "success"})
    else:
        return jsonify({"status": "error", "message": "Too many products"}), 400

# Create GET /export endpoint and print exported products
# Your code here

Hint

Return the products list as JSON in the /export endpoint.

Use Flask's test client to simulate requests and print the exported data.

Practice

1. What HTTP method is commonly used to perform a bulk import of records in a REST API?

easy

A. PUT

B. POST

C. DELETE

D. GET

Solution

1. Step 1: Understand bulk import action

   Bulk import means sending many new records to the server at once.

2. Step 2: Identify HTTP method for creating resources

   POST is used to send data to create new records in REST APIs.

3. Final Answer:

   POST -> Option B

4. Quick Check:

   Bulk import uses POST [OK]

Hint: Bulk import sends data with POST method [OK]

Common Mistakes:

• Choosing GET which is for fetching data
• Using DELETE which removes data
• Confusing PUT with bulk import

2. Which of the following is the correct JSON format to bulk import two user records in a REST API POST request?

easy

A. [{"name": "Alice"}, {"name": "Bob"}]

B. {"name": "Alice", "name": "Bob"}

C. {"users": "Alice, Bob"}

D. ["Alice", "Bob"]

Solution

1. Step 1: Recognize bulk import JSON structure

   Bulk import expects a list (array) of objects, each representing a record.

2. Step 2: Check each option format

   [{"name": "Alice"}, {"name": "Bob"}] is a JSON array with two objects, each with a "name" key. Others are invalid or wrong format.

3. Final Answer:

   [{"name": "Alice"}, {"name": "Bob"}] -> Option A

4. Quick Check:

   Bulk import uses JSON array of objects [OK]

Hint: Bulk import JSON is a list of objects [OK]

Common Mistakes:

• Using a single object with duplicate keys
• Sending a string instead of objects
• Using a simple list of strings without keys

3. Given this REST API response after a bulk export request:

{"users": [{"id":1,"name":"Alice"},{"id":2,"name":"Bob"}]}

What is the value of the second user's name?

medium

A. users

B. Alice

C. 2

D. Bob

Solution

1. Step 1: Locate the users array in the JSON

   The key "users" holds a list of user objects.

2. Step 2: Identify the second user object and its name

   The second object is {"id":2,"name":"Bob"}, so the name is "Bob".

3. Final Answer:

   Bob -> Option D

4. Quick Check:

   Second user's name = Bob [OK]

Hint: Look inside 'users' array, second object's 'name' key [OK]

Common Mistakes:

• Confusing index and picking first user
• Selecting the id instead of name
• Choosing the key name instead of value

4. You try to bulk import records with this JSON:

[{"name": "Alice"}, {"name": "Bob"}

But the server returns a 400 Bad Request error. What is the likely problem?

medium

A. Missing closing bracket in JSON array

B. Using POST instead of GET

C. Names should be numbers, not strings

D. Bulk import requires XML format

Solution

1. Step 1: Check JSON syntax

   The JSON is missing the closing bracket "]" for the array.

2. Step 2: Understand server error meaning

   400 Bad Request often means invalid JSON syntax was sent.

3. Final Answer:

   Missing closing bracket in JSON array -> Option A

4. Quick Check:

   Invalid JSON syntax causes 400 error [OK]

Hint: Check JSON brackets carefully for syntax errors [OK]

Common Mistakes:

• Assuming wrong HTTP method caused error
• Thinking data types must be numbers
• Believing XML is required instead of JSON

5. You want to export all products with price above 100 in bulk from a REST API. Which approach correctly combines bulk export with filtering?

hard

A. Send a DELETE request to /products with filter price>100

B. Send a POST request with JSON [{"price": ">100"}] to /products/export

C. Send a GET request to /products?min_price=100 and parse the returned list

D. Send a PUT request to /products/export with price filter in body

Solution

1. Step 1: Identify correct HTTP method for export

   Bulk export uses GET to retrieve data from the server.

2. Step 2: Use query parameters for filtering

   Filtering by price is done via query string like ?min_price=100.

3. Final Answer:

   Send a GET request to /products?min_price=100 and parse the returned list -> Option C

4. Quick Check:

   Bulk export uses GET with filters in query [OK]

Hint: Use GET with query filters for bulk export [OK]

Common Mistakes:

• Using POST for export instead of GET
• Sending filters in request body for GET
• Using DELETE or PUT incorrectly