5 Python + Flet State Management Explained: useState, Observable Classes, and Game Animation

Описание: Lecture on state in the Flet game we’re building with Python.

How ft.use_state works in Flet, how it compares to React’s useState, and why observable Python classes are often the better choice for complex, mutable game state such as character movement and animation.

Topics covered in this lesson include:
What ft.use_state returns (state + optional setter)
Why the setter can be ignored when using observable objects
Managing game state with a Python @dataclass
How ft.observable enables direct mutation with automatic re-rendering
When to use setters vs. observable classes
Immutable vs. mutable state in Flet
Preventing unnecessary re-renders and infinite render loops
Structuring state for performance and scalability
Using use_effect for animations and one-time setup
Dependency arrays and when effects re-run

Explain game-related data such as sprite position, direction, and animation frame belong in a single observable state object, and how changing any of those values automatically updates only the affected UI component—not the entire screen.

This video is conceptual and architectural, helping you build an understanding of how Flet’s reactive model works. In the next lesson, we apply these ideas directly by adding animation and continuing to move Pepper across the screen.

This tutorial is part of a beginner-friendly Python + Flet series, with a focus on clean architecture, performance, and learning transferable UI state management concepts.