How Flask processes HTTP requests - Try It Yourself

How Flask processes HTTP requests

📖 Scenario: You are building a simple web server using Flask. This server will respond to HTTP requests from users visiting your website.

🎯 Goal: Create a basic Flask app that handles HTTP GET requests and returns a simple message. You will set up the app, configure a route, write the function to process the request, and complete the app run command.

📋 What You'll Learn

Create a Flask app instance named app

Define a route for the URL path /hello

Write a function named hello that returns the text 'Hello, Flask!'

Add the code to run the Flask app with app.run()

💡 Why This Matters

🌍 Real World

Web servers use frameworks like Flask to handle HTTP requests from browsers and return web pages or data.

💼 Career

Understanding how Flask processes requests is essential for backend web development jobs that build APIs and web applications.

1

DATA SETUP: Create the Flask app instance

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

Flask

# Import Flask and create the app instance
# Your code here

Need a hint?

Use from flask import Flask and then app = Flask(__name__) to create the app.

2

CONFIGURATION: Define a route for the URL path /hello

Use the @app.route('/hello') decorator to define a route for the URL path /hello.

Flask

from flask import Flask
app = Flask(__name__)

# Define the route for '/hello'
# Your code here

Need a hint?

Use @app.route('/hello') just before the function that will handle the request.

3

CORE LOGIC: Write the function to handle the request

Write a function named hello that returns the string 'Hello, Flask!'.

Flask

from flask import Flask
app = Flask(__name__)

@app.route('/hello')
# Define the function hello that returns 'Hello, Flask!'
# Your code here

Need a hint?

Define a function named hello that returns the exact string 'Hello, Flask!'.

4

COMPLETION: Add the code to run the Flask app

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

Flask

from flask import Flask
app = Flask(__name__)

@app.route('/hello')
def hello():
    return 'Hello, Flask!'

# Add the code to run the app
# Your code here

Need a hint?

Use the standard Python check if __name__ == '__main__': and call app.run() inside it.