N.B. Do not try to do just Stage 2. This will not work and may break stuff.
Install psychopy from the neurodebian repository (see PsychoPy website), but ensure you use --install-suggests i.e.
sudo apt-get install --install-suggests psychopy
You also should install flac if you don't have it
sudo apt-get install flac
This should give you a working version 1.83.
Stage 2However, some scripts written in the current version 1.85.3, won't work, so you now need to update to the latest version. You can do this using pip install (as covered on the PsychoPy website). I installed the following components listed on the psychopy website, which is mainly the core bits (I did not try to install button box support etc.):
pip install numpy scipy matplotlib pandas pyopengl pyglet pillow moviepy lxml openpyxl configobj psychopy
pip install xlrd
pip install psychopy_ext
pip install python-bidi
pip install cffi pysounddevice pysoundfile
In addition I also had to install the following things not mentioned on the PsychoPy website:
pip install json_tricks