The Flask Mega-Tutorial is an overarching tutorial for Python beginner and intermediate developers that teaches web development with the Flask framework. The tutorial has been thoroughly revised and expanded in 2018, 2021 and lastly in 2024. The concepts that are covered go well beyond Flask, including a wide range of topics Python web developers need to know when writing their own applications.
Miguel Grinberg has over 25 years of experience as a software engineer and currently leads a team of engineers that develop software for the video broadcast industry. He is the author of the O'Reilly book "Flask Web Development", and blogs about a variety of topics including web development, robotics, photography, and the occasional movie review at http://blog.miguelgrinberg.com. He lives in Portland, Oregon with his wife, four kids, two dogs, and a cat.
Totally recommend it for anyone serious about web development. It goes from the basic using Flask and hold your hand building a complete blogging page. It not only shows you how he does it, but he clearly explains why he does it in such a way, and what he's doing so that you can change it and create one for yourself.