Pytorch Text AttributeError: ‘BucketIterator’ object has no attribute

Question

I'm doing seq2seq machine translation on my own dataset. I have preproceed my dataset using this code.

The problem comes when i tried to split train_data using BucketIterator.split()

def tokenize_word(text):
  return nltk.word_tokenize(text)

id = Field(sequential=True, tokenize = tokenize_word, lower=True, init_token="<sos>", eos_token="<eos>")
ti = Field(sequential=True, tokenize = tokenize_word, lower=True, init_token="<sos>", eos_token="<eos>")

fields = {'id': ('i', id), 'ti': ('t', ti)}

train_data = TabularDataset.splits(
    path='/content/drive/MyDrive/Colab Notebooks/Tidore/',
    train = 'id_ti.tsv',
    format='tsv',
    fields=fields
)[0]

id.build_vocab(train_data)
ti.build_vocab(train_data)

print(f"Unique tokens in source (id) vocabulary: {len(id.vocab)}")
print(f"Unique tokens in target (ti) vocabulary: {len(ti.vocab)}")

train_iterator = BucketIterator.splits(
    (train_data),
    batch_size = batch_size,
    sort_within_batch = True,
    sort_key = lambda x: len(x.id),
    device = device
)

print(len(train_iterator))

for data in train_iterator:
  print(data.i)

This is the result of the code above

Unique tokens in source (id) vocabulary: 1425
Unique tokens in target (ti) vocabulary: 1297
2004

---------------------------------------------------------------------------

AttributeError                            Traceback (most recent call last)

<ipython-input-72-e73a211df4bd> in <module>()
     31 
     32 for data in train_iterator:
---> 33   print(data.i)

AttributeError: 'BucketIterator' object has no attribute 'i'

This is the result when i tried to print the train_iterator

I am very confuse, because i don't know what key i should use for train iterator. Thank you for your help

Answer 1

According to torchtext documents , it's better to use TranslationDataset to do what is desired! but if for some reason you prefer to use TabularDataset its better to do it like:

import nltk
print(nltk.__version__)
from torchtext import data
import torchtext
print(torchtext.__version__)
def tokenize_word(text):
    return nltk.word_tokenize(text)

batch_size = 5

SRC = Field(sequential=True, tokenize = tokenize_word, lower=True, init_token="<sos>", eos_token="<eos>")
TRG = Field(sequential=True, tokenize = tokenize_word, lower=True, init_token="<sos>", eos_token="<eos>")

train = data.TabularDataset.splits(
    path='./data/', train='tr.tsv', format='tsv',
    fields=[('src', SRC), ('trg', TRG)])[0]

SRC.build_vocab(train)
TRG.build_vocab(train)

train_iter = data.BucketIterator(
    train, batch_size=batch_size,
    sort_key=lambda x: len(x.text), device=0)

for item in train_iter:
    print(item.trg)

Output:

3.6.2
0.6.0
tensor([[2, 2, 2, 2, 2],
        [5, 5, 5, 5, 5],
        [4, 4, 4, 4, 4],
        [6, 6, 6, 6, 6],
        [7, 7, 7, 7, 7],
        [3, 3, 3, 3, 3]])
tensor([[2, 2, 2, 2, 2],
        [5, 5, 5, 5, 5],
        [4, 4, 4, 4, 4],
        [6, 6, 6, 6, 6],
        [7, 7, 7, 7, 7],
        [3, 3, 3, 3, 3]])

NOTE: make sure there is tr.tsv file contains text columns separated by tab, in data directory. Welcome to stackoverflow & hope it helps :)

Answer 2

 train_iterator = BucketIterator.splits(
(train_data),
batch_size = batch_size,
sort_within_batch = True,
sort_key = lambda x: len(x.id),
device = device

)

here Use BucketIterator instead of BucketIterator.splits when there is only one iterator needs to be generated.

I have met this problem and the method mentioned above works.