What is Flask - Hands-On Activity

What is Flask

📖 Scenario: You want to create a simple web application that shows a greeting message on a webpage.

🎯 Goal: Build a basic Flask app that displays 'Hello, Flask!' when you visit the homepage.

📋 What You'll Learn

Create a Flask app instance named app

Define a route for the homepage using @app.route('/')

Create a function home that returns the string 'Hello, Flask!'

Run the Flask app with app.run()

💡 Why This Matters

🌍 Real World

Flask is used to build websites and web services quickly and simply, like blogs, portfolios, or APIs.

💼 Career

Knowing Flask helps you create backend web applications and APIs, a valuable skill for Python developers.

1

Set up Flask app instance

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

Flask

# Import Flask and create app instance
# Your code here

Need a hint?

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

2

Define homepage route

Use the @app.route('/') decorator to define a route for the homepage.

Flask

from flask import Flask
app = Flask(__name__)

# Define homepage route
# Your code here

Need a hint?

Use @app.route('/') just before the function that handles the homepage.

3

Create homepage function

Define a function called home that returns the string 'Hello, Flask!'.

Flask

from flask import Flask
app = Flask(__name__)

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

Need a hint?

Write def home(): and inside it return 'Hello, Flask!'.

4

Run the Flask app

Add app.run() at the end to start the Flask development server.

Flask

from flask import Flask
app = Flask(__name__)

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

# Run the Flask app
# Your code here

Need a hint?

Simply add app.run() to start the server.