Most will want to simply download the .dmg of the executable from the psychopy website.
Developers can install a local version of the repository using github. See the instructions at the online psychopy documentation "for developers" section.
This requires installation of the python library dependencies. Once that is all done, execute psychopy in the terminal with something like
Rather than type that every time, create an alias, maybe called 'pp', by adding a line to your ~/.profile like this:
alias pp='python /Users/alex/Documents/softwareStatsEquipment/programming_psychophysics/psychopy/psychopy/app/psychopyApp.py'
Psychopy will only run if the location of the dependencies is in your PYTHONPATH. To your ~/.profile file, add the path of psychopy itself with a line like:
And all the other dependencies withz