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ReferenceError: os is not defined

Online experiments
#1

URL of experiment:
https://run.pavlovia.org/jonas.tvedt/gazeproject/?__pilotToken=c20ad4d76fe97759aa27a0c99bff6710&__oauthToken=a72848ae19ac2a14c3ddc63d93b5490500697d9647b91ac1df508a41d649c62a

Description of the problem:

Any ideas how to resolve this? I’m guessing the problem stems from when I define a path in a code component tab, like this:

path = (“images/”)
stimlist = [os.path.join(path, file)
for file in os.listdir(path)
if file.endswith(‘C.png’)]

So I figure the error arrises because os is not imported, but when I add ‘import os’ to a code component tab (before experiment), the experiment gets stuck on ‘initializing experiment…’

#2

You will need to create a spreadsheet containing the names of the files you want.

#3

I see. Thank you. Can the spreadsheet variable be treated similarly as my variable in code? For example:

stimlist = []
for file in spreadsheet:
if file.endswith(‘C.png’)]
stimlist.append(file)

…or something like that?

#4

A quick Google suggests that you might need to change endswith to endsWith

(as well as .append to .push if you aren’t using a code_JS from my crib sheet)

#5

Thanks! But how do I reference the spreadsheet and a specific column so that it works online? Do I have to provide the xlsx file in the conditions file field of a loop or can I read it in from a code component?

#6

Have a look at Trial Handlers in my coding snippets for Python and JS code for importing spreadsheets.

#7

Great! That worked.

#8

There seems to be a problem with the Trial handler method when it is used online. I get this error:

ReferenceError: data is not defined

I guess it comes from this line?:
myData = data.TrialHandler()

#9

That’s a Python line. Did you forget to change the component to Both and edit the JS code?

#10

I did not know that that was necessary. I have the component set to Auto - JS. So if I change it to Both, how should I edit the JS code to get it working?

#11

Have a look at Trial Handlers in my coding snippets for Python and JS code for importing spreadsheets.

#12

ah yes, editing the JS code according to your coding snippet got me past the error. Thanks again.

To anyone having a similar issue: you also have to specify the spreadsheet in the Additional Resources field of the Online tab in the Experiments Settings.

1 Like
#13

Thanks for the reminder. I’ll add this note to the coding snippet page.

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#14

I have one more problem regarding the trialHandler method that maybe you could help me with? How do I get the values, i.e., file names, that I guess are stored in _trialList in dictionaries? In python I could use list comprehension and refer to the column header / key like this:

stim_dict = data.TrialHandler(...)

allstim = [i['faces'] for i in stim_dict]
print('all stimuli',allstim)

I cant seem to find a method that works online with javascript, but I guess there must be some simple way of doing this?

#15

According to my code snippets you should use aValue = myData.trialList[Idx][‘variableName’]

allstim = []
for Idx in range(len(myData.trialList)):
      allstim.append(myData.trialList[Idx]['faces']

Remember to define append as push in code_JS

However, personally I use Builder loops to push straight to lists as per my interleaved lists code.

#16

Thanks! But unfortunately it gets stuck on ‘initializing experiment’ when using this code. It auto translates like this:

allstim = [];
for (var Idx = 0, _pj_a = stim_dict.trialList.length; (Idx < _pj_a); Idx += 1) {
    allstim.push(stim_dict.trialList[Idx]["faces"]);
}
#17

Got past it! I used this python code:

allstim = [i['faces'] for i in stim_dict]
print('all stimuli',allstim)

…which was auto generated to this JS code:

allstim = function () {
    var _pj_a = [], _pj_b = stim_dict;
    for (var _pj_c = 0, _pj_d = _pj_b.length; (_pj_c < _pj_d); _pj_c += 1) {
        var i = _pj_b[_pj_c];
        _pj_a.push(i["faces"]);
    }
    return _pj_a;
}

…then I added .trialList to the myData object manually (thanks for the clue):

allstim = function () {
    var _pj_a = [], _pj_b = stim_dict.trialList;
    for (var _pj_c = 0, _pj_d = _pj_b.length; (_pj_c < _pj_d); _pj_c += 1) {
        var i = _pj_b[_pj_c];
        _pj_a.push(i["faces"]);
    }
    return _pj_a;
}
1 Like