import asyncio import tkinter as tk from async_tkinter_loop import async_handler, async_mainloop async def counter(): i = 0 while True: i += 1 label.config(text=str(i)) await asyncio.sleep(1.0) root = ...

In the button chapter we used time.sleep in a callback function, and it froze everything. This chapter is all about what happened and why. You'll also learn to use things like time.sleep properly with ...