Using asyncio with Tkinter

The tkapp.py and tkapp2.py examples in this folder demonstrate:

• using an alternative asyncio.BaseEventLoop subclass on top of the Tkinter event loop;
• leveraging futures and yield from to escape callback hell;
• applying the asyncio abstractions to GUI programming instead of network programming.

History

The code is adapted from Dino Viehland's (@DinoV) talk Using futures for async GUI programming in Python 3.3 presented at PyCon US 2013. Dino's example used Tulip because the first release of asyncio was not available then; some APIs changed later and the tkapp.py was not working with Python 3.4 and asyncio from the standard library.

Luciano Ramalho (@ramalho) updated this code to run with Python 3.4 with help and encouragement from Guido van Rossum (@gvanrossum). See relevant thread in the python-tulip group.

Ramalho also wrote the tkapp2.py which makes it easier to run the three demonstrations from Viehland's talk: sequential processing, asynchronous with callbacks and asynchronous with coroutines.

Alan Cristhian (@AlanCristhian) fixed the hang-on-exit bug by turning the asyncio event loop thread into a daemon; see guievents.py, method GuiEventLoop._start_io_event_loop.