pytorch用randomsplit分割数据集后遍历数据报错 raise NotImplementedError NotImplementedError

train_len = int(len(train_dataset) * 0.95)
sub_train_, sub_valid_ = torch.utils.data.random_split(train_dataset, [train_len, len(train_dataset) - train_len])#0.95给训练 0.05给验证
print('type(data):', type(train_dataset))
print('type(data):', type(sub_valid_))
print(list(sub_valid_))
for content in sub_valid_:
    print('data:', content)

train_dataset是一个一共三列的数据集
train_dataset: type(data): <class 'torchtext.data.datasets_utils.RawTextIterableDataset'>
sub_train:type(data): <class 'torch.utils.data.dataset.Subset'>

报错如上
我不知道原因出在哪

都告诉你报错的代码行了，你这报错的行一行都没贴出来