Custom status codes in Flask - Mini Project: Build & Apply

Custom status codes in Flask

📖 Scenario: You are building a simple web API using Flask. You want to send custom HTTP status codes with your responses to indicate different situations clearly.

🎯 Goal: Create a Flask app that returns a JSON message with a custom status code when a specific route is accessed.

📋 What You'll Learn

Create a Flask app instance named app

Define a route /status that returns a JSON response

Use a custom status code 299 with the response

Return a JSON dictionary with a key message and value "Custom status code response"

💡 Why This Matters

🌍 Real World

Custom status codes help APIs communicate specific states or errors beyond standard HTTP codes, improving client-server communication.

💼 Career

Understanding how to send custom status codes is useful for backend developers building APIs that need precise control over response statuses.

1

Set up the Flask app

Import Flask from flask and create a Flask app instance called app.

Flask

from flask import Flask

# Create the Flask app instance called app
# Your code here

Need a hint?

Use app = Flask(__name__) to create the app instance.

2

Create a route for /status

Define a route /status using @app.route('/status') and create a function called status that will handle requests to this route.

Flask

from flask import Flask

app = Flask(__name__)

# Define a route /status with a function named status
# Your code here

Need a hint?

Use the @app.route decorator to define the route and a function named status.

3

Return JSON with custom status code

Inside the status function, import jsonify from flask and return a JSON response with {"message": "Custom status code response"} and a custom status code 299.

Flask

from flask import Flask

app = Flask(__name__)

@app.route('/status')
def status():
    # Import jsonify and return JSON with custom status code 299
    # Your code here

Need a hint?

Use return jsonify({...}), 299 to send JSON with a custom status code.

4

Add the app run block

Add the standard Flask app run block: if __name__ == '__main__': and inside it call app.run() to start the server.

Flask

from flask import Flask, jsonify

app = Flask(__name__)

@app.route('/status')
def status():
    return jsonify({"message": "Custom status code response"}), 299

# Add the app run block below
# Your code here

Need a hint?

This block runs the Flask app when the script is executed directly.