How Flask processes HTTP requests - Quick Revision & Summary

Recall & Review

beginner

What is the first step Flask takes when it receives an HTTP request?

Flask receives the HTTP request and creates a Request object that holds all the details like method, URL, headers, and data.

beginner

How does Flask decide which function should handle an incoming HTTP request?

Flask matches the request URL and method to a route defined by the developer using decorators like @app.route(). This tells Flask which function to run.

beginner

What role does the 'view function' play in Flask's request processing?

The view function is the code that runs after Flask matches the route. It processes the request and returns a response, like HTML or JSON.

beginner

What happens after the view function returns a response in Flask?

Flask converts the returned value into an HTTP response object and sends it back to the client (browser or API caller).

intermediate

How does Flask handle errors or requests that don’t match any route?

Flask returns an error response like 404 Not Found if no route matches. Developers can customize error handling with special error handler functions.

What object does Flask create to hold details of an incoming HTTP request?

A Route object

B Response object

C Request object

D Session object

Flask creates a Request object to store all information about the incoming HTTP request.

Which Flask decorator is used to link a URL to a function?

A @app.handle()

B @app.view()

C @app.request()

D @app.route()

The @app.route() decorator tells Flask which URL should trigger the decorated function.

What does a Flask view function return?

A An HTTP response or data to build one

B A URL string

C A Request object

D A database connection

The view function returns data or a response that Flask converts into an HTTP response sent to the client.

What status code does Flask return if no route matches the request URL?

A 404 Not Found

B 200 OK

C 500 Internal Server Error

D 301 Moved Permanently

Flask returns a 404 Not Found error when no route matches the requested URL.

Which step comes directly after Flask matches a route to a request?

A Send response to client

B Run the view function

C Create a Request object

D Log the request

After matching the route, Flask runs the view function to process the request.

Explain the journey of an HTTP request through Flask from arrival to response.

Think about what Flask does step-by-step when a browser asks for a page.

Describe how Flask handles a request that does not match any defined route.

What happens when you visit a page that does not exist in a Flask app?