ValueError: Expected a torch.device with a specified index or an integer, but got:[0, 1]

This error occurs when trying to initialize a PyTorch device with a list of indices instead of a single index or a device string.

To fix this error, specify a single index or device string when initializing the device. For example:

import torch

# Initialize device with single index
device = torch.device(0)

# Initialize device with device string
device = torch.device('cuda')

If you need to use multiple GPUs, you can use PyTorch's `DataParallel` module to distribute the workload across the GPUs.