msync is a command line client for Mastodon (and anything else that implements the same API, including Pleroma) that works a little different. msync doesn't stay connected to the internet all the time and constantly pull new posts. Instead, it only connects when you use the msync sync command. Every other change is stored on your computer until then. You can queue up posts to send, boost, bookmark, and favorite when you're online, download posts, notifications, and bookmarks to look at offline, and do the same for as many accounts as you want.
msync currently supports queueing and sending posts, boosts, favorites, and bookmarks for any number of accounts, as well as downloading the home timeline, notifications, bookmarks, and arbitrary threads.
TinyXMPP is a small XMPP client library for Python applications. It allows developers to easily connect to XMPP servers and exchange messages in a fast and secure way.
The only demo code seems to be in the README right now.
A Python module for accessing a Matrix server that is built using the no-I/O methodology - it conceals all of the input and output so development is focused on assembling what is sent and using what is received. Asynchronous in nature. In Pypi. Also end-to-end encryption capable. I don't know how flexible this library is so more investigation is required.
Slixmpp is an MIT licensed XMPP library for Python 3.5+. It is a fork of SleekXMPP because Sleek is no longer maintained.
Slixmpp's goals is to only rewrite the core of the library (the low level socket handling, the timers, the events dispatching) in order to remove all threads.
By and large, it seems as if you could just drop this module in and it'd work. My code uses threads, so it might take a little more tinkering than that.
Asyncoro is a Python framework for writing massively distributed applications. Designed to work in an asynchronous fashion (including non-blocking network socket handling) on as many OSes as possible. Supports SSL, locking, execution of routines on remote systems, and hot-swapping of code. Even does asynchronous database access.