同样的，当电脑中同时有CUDA和CPU环境时，transformer_sent_polarity.py文件也会报错
RuntimeError: Expected all tensors to be on the same device, but found at least two devices, cuda:0 and cpu!
第四章文件utils.py的第25行
mask = torch.arange(max_len).expand(lengths.shape[0], max_len) < lengths.unsqueeze(1)
也应修改为：
mask = torch.arange(max_len).expand(lengths.shape[0], max_len).cuda() < lengths.unsqueeze(1)
如题，直接运行会报错。
RuntimeError: 'lengths' argument should be a 1D CPU int64 tensor, but got 1D cuda:0 Long tensor需要把'lengths'放到cpu中去，才可以。
将第40行的
x_pack = pack_padded_sequence(embeddings, lengths, batch_first=True, enforce_sorted=False)改为x_pack = pack_padded_sequence(embeddings, lengths.cpu(), batch_first=True, enforce_sorted=False)同样的，当电脑中同时有CUDA和CPU环境时，
transformer_sent_polarity.py文件也会报错RuntimeError: Expected all tensors to be on the same device, but found at least two devices, cuda:0 and cpu!第四章文件utils.py的第25行mask = torch.arange(max_len).expand(lengths.shape[0], max_len) < lengths.unsqueeze(1)也应修改为：mask = torch.arange(max_len).expand(lengths.shape[0], max_len).cuda() < lengths.unsqueeze(1)