def indexesFromSentence(lang, sentence):
    return [lang.word2index[word] for word in sentence.split(' ')]

def tensorFromSentence(lang, sentence):
    indexes = indexesFromSentence(lang, sentence)
    indexes.append(EOS_token)
    return [torch.tensor](https://docs.pytorch.org/docs/stable/generated/torch.tensor.html#torch.tensor "torch.tensor")(indexes, dtype=[torch.long](https://docs.pytorch.org/docs/stable/tensor_attributes.html#torch.dtype "torch.dtype"), [device](https://docs.pytorch.org/docs/stable/tensor_attributes.html#torch.device "torch.device")=[device](https://docs.pytorch.org/docs/stable/tensor_attributes.html#torch.device "torch.device")).view(1, -1)

def tensorsFromPair(pair):
    input_tensor = tensorFromSentence(input_lang, pair[0])
    target_tensor = tensorFromSentence(output_lang, pair[1])
    return (input_tensor, target_tensor)

def get_dataloader(batch_size):
    input_lang, output_lang, pairs = prepareData('eng', 'fra', True)

    n = len(pairs)
    input_ids = np.zeros((n, MAX_LENGTH), dtype=np.int32)
    target_ids = np.zeros((n, MAX_LENGTH), dtype=np.int32)

    for idx, (inp, tgt) in enumerate(pairs):
        inp_ids = indexesFromSentence(input_lang, inp)
        tgt_ids = indexesFromSentence(output_lang, tgt)
        inp_ids.append(EOS_token)
        tgt_ids.append(EOS_token)
        input_ids[idx, :len(inp_ids)] = inp_ids
        target_ids[idx, :len(tgt_ids)] = tgt_ids

    train_data = [TensorDataset](https://docs.pytorch.org/docs/stable/data.html#torch.utils.data.TensorDataset "torch.utils.data.TensorDataset")(torch.LongTensor(input_ids).to([device](https://docs.pytorch.org/docs/stable/tensor_attributes.html#torch.device "torch.device")),
                               torch.LongTensor(target_ids).to([device](https://docs.pytorch.org/docs/stable/tensor_attributes.html#torch.device "torch.device")))

    train_sampler = [RandomSampler](https://docs.pytorch.org/docs/stable/data.html#torch.utils.data.RandomSampler "torch.utils.data.RandomSampler")(train_data)
    [train_dataloader](https://docs.pytorch.org/docs/stable/data.html#torch.utils.data.DataLoader "torch.utils.data.DataLoader") = [DataLoader](https://docs.pytorch.org/docs/stable/data.html#torch.utils.data.DataLoader "torch.utils.data.DataLoader")(train_data, sampler=train_sampler, batch_size=batch_size)
    return input_lang, output_lang, [train_dataloader](https://docs.pytorch.org/docs/stable/data.html#torch.utils.data.DataLoader "torch.utils.data.DataLoader")