I don’t think you can actually do what you want to do from within the builder. But, it’s easy to do.
For this to work, I assume you built your experiment with the builder, and you didn’t alter anything in the code.
Go to the builder view of your experiment, and click on the “compile script” button.
You should see a screen with all the code for your experiment.
Find the line that says,
#Data file name stem = absolute path + name; later add .psyexp, .csv, .log, etc
filename = _thisDir + os.sep + u'data/%s_%s_%s' %(expInfo['participant'], expName, expInfo['date'])
This tells psychopy where to save your data files.
I assume you want to save your files in some place other than where you start up your experimental script. For example, my you want to save in the folder,
then you could remove
_thisDir + os.sep + u'data/
from the filename variable, and replace it with,
"/users/sami/desktop/samisExperimentData/" + expInfo['participant'] + expName + expInfo['date']
I would recommend keeping all of the details about this particular experimental run, i.e.
expInfo['participant'] + expName + expInfo['date']
I would further recommend you normalize the filename variable with the os.path.normpath(path) function. You can read about it here. Your new filename variable in the code is thus:
filename = os.path.normpath("/users/sami/desktop/samisExperimentData/" + expInfo['participant'] + expName + expInfo['date'])
For this to work properly, I assume you have already the file at the location,
Also, if you wanted to actually create a file for each new participant, then you could similarly hack your way to it. Just use the function, os.mkdir(path), which you can read about here.