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Unable to randomly choose subset of items from a longer list

If this template helps then use it. If not then just delete and start from scratch.

OS (e.g. Win10):
PsychoPy version (e.g. 1.84.x): Latest
Standard Standalone? (y/n) Y If not then what?:
What are you trying to achieve?:
I am trying to randomly choose a subset of items from a longer list to be presented on the screen. For example, I have a list 110 images, I want to randomly choose 55 from the list to present to a subject. I would like to do it in builder without custom code which according to Psychopy website I should be able to do easily.
What did you try to make it work?:
Please refer to the attache image.
What specifically went wrong when you tried that?:
It gave an error, list not iterable I think.

Include pasted full error message if possible. “That didn’t work” is not enough information.

Much thanks in advance

Ooh, that line isn’t great advice. That example would actually just give you 4 floating point numbers, rather than nicely behaved integers, and even if you rounded them, you might get duplicates. You would be better off with something like this:

$np.random.choice(110, size = 55, replace = False)

Documentation here:

Can you let me know if that works, so I can update that help page accordingly?

1 Like

Can I copy paste the python code in the “Selected rows” input box ? I will give it a try and let you know. Thanks !