Obtaining individual items in 'output' of inference?

[cooldecola]

I'm trying to run detectron2 on video and for each frame I compute

boxes = outputs['instances'].pred_boxes
How do I get each individual item in the list?

When I try
print(boxes[0][0])
or print(boxes[0])
I get the error saying:
list index out of range

I've also tried boxes = np.asarray((outputs['instances'].pred_boxes.tensor.cpu().numpy()))
I get this format
[[x x x x]]
and I cannot access the individual items because there is no comma.

Any help would be great. How do I get individual items?
Thanks