PySimpleGUI/docs/eCookbook/demo-programs/design-pattern-2-persistent-window-with-updates.md

Design Pattern 2 - Persistent Windows, output updates in window

***This is the most common design pattern you'll find in PySimpleGUI. ***

It's the same across all of the ports of PySimpleGUI. You'll easily be able to recognize a PySimpleGUI program by this basic structure.

This pattern is for windows that remain open with the user interacting with them. It's a "normal" window from a user's standpoint.

This pattern has 4 parts:

1. Layout definition
2. Window creation
3. Event loop - read window events and inputs
4. Window close

Each of these parts is 1 or 2 lines of Python code when working with a basic window. The size of the event loop depends on the amount of processing you need to do when events happen in the window.