Randomization of columns in condition file

[Omidrezaa]

Dear Michael,

I corrected the position of my codes and I debug the previous error. However, I got a new error:

I read some of your comments on this question and I tried to use your suggestions:

Creating a four alternative forced choice task

Dear Michael, Apologies for the late reply. Thank you for your advice! I implemented the code you suggested. It seems to partially work as expected…but the experiment intermittently crashes and throws the following error: corrAns = responses[indices[0]] IndexError: list index out of range Do you know what might be going wrong…? Thanks again, Lyam

Thus I wrote these two lone of code to find out the problem:

print len (Choice)
print (Choice [0])

Nevertheless, I faced with the error: object of type ‘BuilderKeyResponse’ has no len().

This is the final step of my experiment and I would appreciate any comments.