expected sequence of length 80 at dim 3 (got 40)

[baiye1248]

for i in range(self.nl):
# anchors, shape = self.anchors[i], p[i].shape
anchors, shape = self.anchors[i],(torch.tensor([p.cpu().detach().numpy() for p in p[i]])).cuda().shape#Modify the above
gain[2:6] = torch.tensor(shape)[[3, 2, 3, 2]] # xyxy gain

An error has occurred：ValueError: expected sequence of length 80 at dim 3 (got 40)