Question

Looking at the default “Hello world” script on Flask’s website:

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

if __name__ == "__main__":
    app.run()

I’m very new to programming, so I don’t understand how this script can work – the hello() function isn’t called anywhere, so does Flask simply display the output of the first function found? What if I wanted to display outputs from two or three functions on the page?

Answer 1

This line: @app.route("/") will register the function as the handler for the ‘/’ route. When the browser queries ‘/’ (the root), the application responds “Hello World!”.

The @ syntax is called Decorators.

How to make a chain of function decorators?