Promoting @tarruda 's comment on #83 into its own bug:

The only way to truly fix neovim_mod.py is to refactor it to use the new remote screen facility and parse screen updates according to your expectations. Unfortunately there's no documentation explaining on how to do it, but there is a complete implementation of a remote neovim UI in the python-client package: https://github.com/neovim/python-client/tree/master/neovim/ui

FWIW we also use this facility to test neovim with the lua client.
here's an example test: https://github.com/neovim/neovim/blob/master/test/functional/ui/mouse_spec.lua
and here is the screen class that implements an abstract screen for testing: https://github.com/neovim/neovim/blob/master/test/functional/ui/screen.lua