HTTP status codes for APIs in Flask - Mini Project: Build & Apply

HTTP status codes for APIs

📖 Scenario: You are building a simple web API using Flask. This API will respond to client requests with data and appropriate HTTP status codes to indicate success or errors.

🎯 Goal: Create a Flask API with one route that returns JSON data and uses HTTP status codes to show if the request was successful or if there was an error.

📋 What You'll Learn

Create a Flask app with one route /api/data

Return JSON data with a success message and HTTP status code 200

Add a condition to return an error message with HTTP status code 404 if data is missing

Use Flask's jsonify and make_response to send responses

💡 Why This Matters

🌍 Real World

APIs use HTTP status codes to tell clients if their request worked or if there was a problem. This helps apps communicate clearly over the web.

💼 Career

Knowing how to use HTTP status codes in APIs is essential for backend developers, web developers, and anyone building web services.

1

Set up Flask app and data

Import Flask and jsonify from flask. Create a Flask app called app. Create a dictionary called data with the entry 'message': 'Hello, API!'.

Flask

from flask import Flask, jsonify

# Create Flask app
app = Flask(__name__)

# Create data dictionary
# Your code here

Need a hint?

Use data = {'message': 'Hello, API!'} exactly to create the data dictionary.

2

Add a config variable for data availability

Create a variable called data_available and set it to True. This will simulate whether the data is available or not.

Flask

from flask import Flask, jsonify

app = Flask(__name__)

data = {'message': 'Hello, API!'}

# Create data_available variable
# Your code here

Need a hint?

Set data_available = True exactly as shown.

3

Create the API route with status codes

Define a route /api/data using @app.route. Create a function called get_data. Inside it, use an if statement to check if data_available is True. If yes, return jsonify(data) with status code 200. Otherwise, return jsonify({'error': 'Data not found'}) with status code 404. Use make_response to set the status code.

Flask

from flask import Flask, jsonify, make_response

app = Flask(__name__)

data = {'message': 'Hello, API!'}

data_available = True

# Create /api/data route
# Your code here

Need a hint?

Use @app.route('/api/data') and define get_data(). Use make_response with jsonify and status codes 200 or 404.

4

Add the app run command

Add the code to run the Flask app only if the script is run directly. Use if __name__ == '__main__': and inside it call app.run(debug=True).

Flask

from flask import Flask, jsonify, make_response

app = Flask(__name__)

data = {'message': 'Hello, API!'}

data_available = True

@app.route('/api/data')
def get_data():
    if data_available:
        return make_response(jsonify(data), 200)
    else:
        return make_response(jsonify({'error': 'Data not found'}), 404)

# Add app run command
# Your code here

Need a hint?

Use the standard Flask app run block with debug=True for easy testing.