dl_seq2seq/fin-to-en-seq2seq-v3.ipynb

119 KiB

from __future__ import unicode_literals, print_function, division
from io import open
import unicodedata
import re
import random

import torch
import torch.nn as nn
from torch import optim
import torch.nn.functional as F

import numpy as np
from torch.utils.data import TensorDataset, DataLoader, RandomSampler

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
torch.cuda.device_count()
2

Konwersja słów na index

SOS_token = 0
EOS_token = 1

class Lang:
    def __init__(self, name):
        self.name = name
        self.word2index = {}
        self.word2count = {}
        self.index2word = {0: "SOS", 1: "EOS"}
        self.n_words = 2  # Count SOS and EOS

    def addSentence(self, sentence):
        for word in sentence.split(' '):
            self.addWord(word)

    def addWord(self, word):
        if word not in self.word2index:
            self.word2index[word] = self.n_words
            self.word2count[word] = 1
            self.index2word[self.n_words] = word
            self.n_words += 1
        else:
            self.word2count[word] += 1

Normalizacja tekstu

# Turn a Unicode string to plain ASCII, thanks to
# https://stackoverflow.com/a/518232/2809427
def unicodeToAscii(s):
    return ''.join(
        c for c in unicodedata.normalize('NFD', s)
        if unicodedata.category(c) != 'Mn'
    )

# Lowercase, trim, and remove non-letter characters
def normalizeString(s):
    s = unicodeToAscii(s.lower().strip())
    s = re.sub(r"([.!?])", r" \1", s)
    s = re.sub(r"[^a-zA-Z!?]+", r" ", s)
    return s.strip()

Wczytywanie danych (zmodyfikowane ze względu na ścieżkę w kaggle)

# Zmodyfikowana wersja ze względu na użycie pojedynczego pliku przesłanego na Kaggle
def readLangs(reverse=False):
    print("Reading lines...")
    lang1="en"
    lang2="fin"
    # Read the file and split into lines
    lines = open('/kaggle/input/anki-en-fin/fin.txt', encoding='utf-8').\
        read().strip().split('\n')

    # Split every line into pairs and normalize
    pairs = [[normalizeString(s) for s in l.split('\t')[:-1]] for l in lines] # +Usuwanie licencji CC z linii

    # Reverse pairs, make Lang instances
    if reverse:
        pairs = [list(reversed(p)) for p in pairs]
        input_lang = Lang(lang2)
        output_lang = Lang(lang1)
    else:
        input_lang = Lang(lang1)
        output_lang = Lang(lang2)

    return input_lang, output_lang, pairs

Ograniczenie do zdań max 10 słów, formy I am / You are / He is etc. bez interpunkcji

MAX_LENGTH = 10

eng_prefixes = (
    "i am ", "i m ",
    "he is", "he s ",
    "she is", "she s ",
    "you are", "you re ",
    "we are", "we re ",
    "they are", "they re "
)

def filterPair(p):
    return len(p[0].split(' ')) < MAX_LENGTH and \
        len(p[1].split(' ')) < MAX_LENGTH and \
        p[1].startswith(eng_prefixes)


def filterPairs(pairs):
    return [pair for pair in pairs if filterPair(pair)]
def prepareData(reverse=False):
    input_lang, output_lang, pairs = readLangs(reverse)
    print("Read %s sentence pairs" % len(pairs))
    pairs = filterPairs(pairs)
    print("Trimmed to %s sentence pairs" % len(pairs))
    print("Counting words...")
    for pair in pairs:
        input_lang.addSentence(pair[0])
        output_lang.addSentence(pair[1])
    print("Counted words:")
    print(input_lang.name, input_lang.n_words)
    print(output_lang.name, output_lang.n_words)
    return input_lang, output_lang, pairs

input_lang, output_lang, pairs = prepareData(True)
print(random.choice(pairs))
Reading lines...
Read 72258 sentence pairs
Trimmed to 5005 sentence pairs
Counting words...
Counted words:
fin 3686
en 1971
['mina odotan joulua innolla', 'i am looking forward to christmas']

Definicja modelu

class EncoderRNN(nn.Module):
    def __init__(self, input_size, hidden_size, dropout_p=0.1):
        super(EncoderRNN, self).__init__()
        self.hidden_size = hidden_size

        self.embedding = nn.Embedding(input_size, hidden_size)
        self.gru = nn.GRU(hidden_size, hidden_size, batch_first=True)
        self.dropout = nn.Dropout(dropout_p)

    def forward(self, input):
        embedded = self.dropout(self.embedding(input))
        output, hidden = self.gru(embedded)
        return output, hidden
class DecoderRNN(nn.Module):
    def __init__(self, hidden_size, output_size):
        super(DecoderRNN, self).__init__()
        self.embedding = nn.Embedding(output_size, hidden_size)
        self.gru = nn.GRU(hidden_size, hidden_size, batch_first=True)
        self.out = nn.Linear(hidden_size, output_size)

    def forward(self, encoder_outputs, encoder_hidden, target_tensor=None):
        batch_size = encoder_outputs.size(0)
        decoder_input = torch.empty(batch_size, 1, dtype=torch.long, device=device).fill_(SOS_token)
        decoder_hidden = encoder_hidden
        decoder_outputs = []

        for i in range(MAX_LENGTH):
            decoder_output, decoder_hidden  = self.forward_step(decoder_input, decoder_hidden)
            decoder_outputs.append(decoder_output)

            if target_tensor is not None:
                # Teacher forcing: Feed the target as the next input
                decoder_input = target_tensor[:, i].unsqueeze(1) # Teacher forcing
            else:
                # Without teacher forcing: use its own predictions as the next input
                _, topi = decoder_output.topk(1)
                decoder_input = topi.squeeze(-1).detach()  # detach from history as input

        decoder_outputs = torch.cat(decoder_outputs, dim=1)
        decoder_outputs = F.log_softmax(decoder_outputs, dim=-1)
        return decoder_outputs, decoder_hidden, None # We return `None` for consistency in the training loop

    def forward_step(self, input, hidden):
        output = self.embedding(input)
        output = F.relu(output)
        output, hidden = self.gru(output, hidden)
        output = self.out(output)
        return output, hidden
class BahdanauAttention(nn.Module):
    def __init__(self, hidden_size):
        super(BahdanauAttention, self).__init__()
        self.Wa = nn.Linear(hidden_size, hidden_size)
        self.Ua = nn.Linear(hidden_size, hidden_size)
        self.Va = nn.Linear(hidden_size, 1)

    def forward(self, query, keys):
        scores = self.Va(torch.tanh(self.Wa(query) + self.Ua(keys)))
        scores = scores.squeeze(2).unsqueeze(1)

        weights = F.softmax(scores, dim=-1)
        context = torch.bmm(weights, keys)

        return context, weights

class AttnDecoderRNN(nn.Module):
    def __init__(self, hidden_size, output_size, dropout_p=0.1):
        super(AttnDecoderRNN, self).__init__()
        self.embedding = nn.Embedding(output_size, hidden_size)
        self.attention = BahdanauAttention(hidden_size)
        self.gru = nn.GRU(2 * hidden_size, hidden_size, batch_first=True)
        self.out = nn.Linear(hidden_size, output_size)
        self.dropout = nn.Dropout(dropout_p)

    def forward(self, encoder_outputs, encoder_hidden, target_tensor=None):
        batch_size = encoder_outputs.size(0)
        decoder_input = torch.empty(batch_size, 1, dtype=torch.long, device=device).fill_(SOS_token)
        decoder_hidden = encoder_hidden
        decoder_outputs = []
        attentions = []

        for i in range(MAX_LENGTH):
            decoder_output, decoder_hidden, attn_weights = self.forward_step(
                decoder_input, decoder_hidden, encoder_outputs
            )
            decoder_outputs.append(decoder_output)
            attentions.append(attn_weights)

            if target_tensor is not None:
                # Teacher forcing: Feed the target as the next input
                decoder_input = target_tensor[:, i].unsqueeze(1) # Teacher forcing
            else:
                # Without teacher forcing: use its own predictions as the next input
                _, topi = decoder_output.topk(1)
                decoder_input = topi.squeeze(-1).detach()  # detach from history as input

        decoder_outputs = torch.cat(decoder_outputs, dim=1)
        decoder_outputs = F.log_softmax(decoder_outputs, dim=-1)
        attentions = torch.cat(attentions, dim=1)

        return decoder_outputs, decoder_hidden, attentions


    def forward_step(self, input, hidden, encoder_outputs):
        embedded =  self.dropout(self.embedding(input))

        query = hidden.permute(1, 0, 2)
        context, attn_weights = self.attention(query, encoder_outputs)
        input_gru = torch.cat((embedded, context), dim=2)

        output, hidden = self.gru(input_gru, hidden)
        output = self.out(output)

        return output, hidden, attn_weights
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(indexes, dtype=torch.long, device=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(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(torch.LongTensor(input_ids).to(device),
                               torch.LongTensor(target_ids).to(device))

    train_sampler = RandomSampler(train_data)
    train_dataloader = DataLoader(train_data, sampler=train_sampler, batch_size=batch_size)
    return input_lang, output_lang, train_dataloader
def train_epoch(dataloader, encoder, decoder, encoder_optimizer,
          decoder_optimizer, criterion):

    total_loss = 0
    for data in dataloader:
        input_tensor, target_tensor = data

        encoder_optimizer.zero_grad()
        decoder_optimizer.zero_grad()

        encoder_outputs, encoder_hidden = encoder(input_tensor)
        decoder_outputs, _, _ = decoder(encoder_outputs, encoder_hidden, target_tensor)

        loss = criterion(
            decoder_outputs.view(-1, decoder_outputs.size(-1)),
            target_tensor.view(-1)
        )
        loss.backward()

        encoder_optimizer.step()
        decoder_optimizer.step()

        total_loss += loss.item()

    return total_loss / len(dataloader)
import time
import math

def asMinutes(s):
    m = math.floor(s / 60)
    s -= m * 60
    return '%dm %ds' % (m, s)

def timeSince(since, percent):
    now = time.time()
    s = now - since
    es = s / (percent)
    rs = es - s
    return '%s (- %s)' % (asMinutes(s), asMinutes(rs))
def train(train_dataloader, encoder, decoder, n_epochs, learning_rate=0.001,
               print_every=100, plot_every=100):
    start = time.time()
    plot_losses = []
    print_loss_total = 0  # Reset every print_every
    plot_loss_total = 0  # Reset every plot_every

    encoder_optimizer = optim.Adam(encoder.parameters(), lr=learning_rate)
    decoder_optimizer = optim.Adam(decoder.parameters(), lr=learning_rate)
    criterion = nn.NLLLoss()

    for epoch in range(1, n_epochs + 1):
        loss = train_epoch(train_dataloader, encoder, decoder, encoder_optimizer, decoder_optimizer, criterion)
        print_loss_total += loss
        plot_loss_total += loss

        if epoch % print_every == 0:
            print_loss_avg = print_loss_total / print_every
            print_loss_total = 0
            print('%s (%d %d%%) %.4f' % (timeSince(start, epoch / n_epochs),
                                        epoch, epoch / n_epochs * 100, print_loss_avg))

        if epoch % plot_every == 0:
            plot_loss_avg = plot_loss_total / plot_every
            plot_losses.append(plot_loss_avg)
            plot_loss_total = 0

    showPlot(plot_losses)
import matplotlib.pyplot as plt
plt.switch_backend('agg')
import matplotlib.ticker as ticker
import numpy as np
%matplotlib inline

def showPlot(points):
    plt.figure()
    fig, ax = plt.subplots()
    # this locator puts ticks at regular intervals
    loc = ticker.MultipleLocator(base=0.2)
    ax.yaxis.set_major_locator(loc)
    plt.plot(points)

Ewaluacja

def evaluate(encoder, decoder, sentence, input_lang, output_lang):
    with torch.no_grad():
        input_tensor = tensorFromSentence(input_lang, sentence)

        encoder_outputs, encoder_hidden = encoder(input_tensor)
        decoder_outputs, decoder_hidden, decoder_attn = decoder(encoder_outputs, encoder_hidden)

        _, topi = decoder_outputs.topk(1)
        decoded_ids = topi.squeeze()

        decoded_words = []
        for idx in decoded_ids:
            if idx.item() == EOS_token:
                decoded_words.append('<EOS>')
                break
            decoded_words.append(output_lang.index2word[idx.item()])
    return decoded_words, decoder_attn
def evaluateRandomly(encoder, decoder, n=10):
    for i in range(n):
        pair = random.choice(pairs)
        print('Input sentence: ', pair[0])
        print('Target (true) translation:' , pair[1])
        output_words, _ = evaluate(encoder, decoder, pair[0], input_lang, output_lang)
        output_sentence = ' '.join(output_words)
        print('Output sentence: ', output_sentence)
        print('')

Wykorzystanie zdefiniowanych wyżej funkcji

Trenowanie modelu

hidden_size = 128
batch_size = 32

input_lang, output_lang, train_dataloader = get_dataloader(batch_size)

encoder = EncoderRNN(input_lang.n_words, hidden_size).to(device)
decoder = AttnDecoderRNN(hidden_size, output_lang.n_words).to(device)

train(train_dataloader, encoder, decoder, 80, print_every=5, plot_every=5)
Reading lines...
Read 72258 sentence pairs
Trimmed to 5005 sentence pairs
Counting words...
Counted words:
fin 3686
en 1971
0m 21s (- 5m 21s) (5 6%) 1.9364
0m 36s (- 4m 17s) (10 12%) 1.0355
0m 51s (- 3m 45s) (15 18%) 0.6313
1m 7s (- 3m 21s) (20 25%) 0.3787
1m 22s (- 3m 1s) (25 31%) 0.2243
1m 37s (- 2m 42s) (30 37%) 0.1371
1m 52s (- 2m 25s) (35 43%) 0.0903
2m 7s (- 2m 7s) (40 50%) 0.0668
2m 23s (- 1m 51s) (45 56%) 0.0538
2m 38s (- 1m 34s) (50 62%) 0.0471
2m 53s (- 1m 18s) (55 68%) 0.0410
3m 8s (- 1m 2s) (60 75%) 0.0381
3m 23s (- 0m 47s) (65 81%) 0.0343
3m 38s (- 0m 31s) (70 87%) 0.0342
3m 54s (- 0m 15s) (75 93%) 0.0322
4m 9s (- 0m 0s) (80 100%) 0.0307
evaluateRandomly(encoder, decoder)
Input sentence:  olen hyvin hyvin vihainen
Target (true) translation: i m very very angry
Output sentence:  i am very angry today <EOS>

Input sentence:  han valehtelee
Target (true) translation: he s lying
Output sentence:  he is telling a lie <EOS>

Input sentence:  olen myohassa
Target (true) translation: i m late
Output sentence:  i m late <EOS>

Input sentence:  han on linja autonkuljettaja
Target (true) translation: he is a bus driver
Output sentence:  he is a bus driver <EOS>

Input sentence:  mukava tavata sinut taas
Target (true) translation: i m glad to see you again
Output sentence:  i m glad to see you again <EOS>

Input sentence:  olet kuumeessa
Target (true) translation: you re running a fever
Output sentence:  you re so predictable <EOS>

Input sentence:  anteeksi mutta unohdin tehda laksyt
Target (true) translation: i m sorry i forgot to do my homework
Output sentence:  i m sorry i forgot to do my homework <EOS>

Input sentence:  mina olen tyoton
Target (true) translation: i m unemployed
Output sentence:  i m unemployed <EOS>

Input sentence:  olen taynna
Target (true) translation: i am full
Output sentence:  i am full of french <EOS>

Input sentence:  ma kuolen nalkaan !
Target (true) translation: i m dying of hunger
Output sentence:  i m dying of hunger <EOS>

def showAttention(input_sentence, output_words, attentions):
    fig = plt.figure()
    ax = fig.add_subplot(111)
    cax = ax.matshow(attentions.cpu().numpy(), cmap='bone')
    fig.colorbar(cax)

    # Set up axes
    ax.set_xticklabels([''] + input_sentence.split(' ') +
                       ['<EOS>'], rotation=90)
    ax.set_yticklabels([''] + output_words)

    # Show label at every tick
    ax.xaxis.set_major_locator(ticker.MultipleLocator(1))
    ax.yaxis.set_major_locator(ticker.MultipleLocator(1))

    plt.show()


def evaluateAndShowAttention(input_sentence):
    input_sentence = normalizeString(input_sentence)
    output_words, attentions = evaluate(encoder, decoder, input_sentence, input_lang, output_lang)
    print('input =', input_sentence)
    print('output =', ' '.join(output_words))
    showAttention(input_sentence, output_words, attentions[0, :len(output_words), :])

def translate(input_sentence, tokenized=False):
    input_sentence = normalizeString(input_sentence)
    output_words, attentions = evaluate(encoder, decoder, input_sentence, input_lang, output_lang)
    if tokenized:
        if "<EOS>" in output_words:
            output_words.remove("<EOS>")
        return output_words
    return ' '.join(output_words)
translate("Meillä on nälkä", tokenized=True)
['we', 'are', 'hungry']
evaluateAndShowAttention('Olet liian naivi')
input = olet liian naivi
output = you re too naive <EOS>
/tmp/ipykernel_34/2052950992.py:8: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_xticklabels([''] + input_sentence.split(' ') +
/tmp/ipykernel_34/2052950992.py:10: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_yticklabels([''] + output_words)
evaluateAndShowAttention('Olen todella pahoillani')
input = olen todella pahoillani
output = i am truly sorry <EOS>
/tmp/ipykernel_34/2052950992.py:8: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_xticklabels([''] + input_sentence.split(' ') +
/tmp/ipykernel_34/2052950992.py:10: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_yticklabels([''] + output_words)
evaluateAndShowAttention('Olet minun isäni')
input = olet minun isani
output = you re my father <EOS>
/tmp/ipykernel_34/2052950992.py:8: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_xticklabels([''] + input_sentence.split(' ') +
/tmp/ipykernel_34/2052950992.py:10: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_yticklabels([''] + output_words)
evaluateAndShowAttention('Hän on opettaja')
input = han on opettaja
output = he is a teacher <EOS>
/tmp/ipykernel_34/2052950992.py:8: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_xticklabels([''] + input_sentence.split(' ') +
/tmp/ipykernel_34/2052950992.py:10: UserWarning: FixedFormatter should only be used together with FixedLocator
  ax.set_yticklabels([''] + output_words)
torch.save(encoder.state_dict(), "encoder.pt")
torch.save(decoder.state_dict(), "decoder.pt")

BLEU score

Jako że korzystaliśmy z okrojonej wersji zbioru danych, słownik nie zawiera wszystkich słów pojawiających się w przykładach więc do ewaluacji wykorzystujemy część przykładów z treningu

import pandas as pd


def filter_rows(row):
    return len(row["English"].split(' '))<MAX_LENGTH and \
                        len(row["Finnish"].split(' '))<MAX_LENGTH and \
                        row["English"].startswith(eng_prefixes)
data_file = pd.read_csv("/kaggle/input/anki-en-fin/fin.txt", sep='\t', names=["English","Finnish","attribution"])
data_file["English"] = data_file["English"].apply(normalizeString)
data_file["Finnish"] = data_file["Finnish"].apply(normalizeString)

filter_list = data_file.apply(filter_rows, axis=1)

test_section = data_file[filter_list]
test_section = test_section.sample(frac=1).head(500)
test_section.head()
English Finnish attribution
38027 i m very serious about this olen hyvin tosissani tasta CC-BY 2.0 (France) Attribution: tatoeba.org #2...
3803 i m not tired en ole vasynyt CC-BY 2.0 (France) Attribution: tatoeba.org #1...
26924 i m not married either minakaan en ole naimisissa CC-BY 2.0 (France) Attribution: tatoeba.org #6...
32009 he s sleeping like a baby han nukkuu kuin pikkuvauva CC-BY 2.0 (France) Attribution: tatoeba.org #2...
21339 i m joking of course se oli vitsi tietenkin CC-BY 2.0 (France) Attribution: tatoeba.org #2...
test_section["English_tokenized"] = test_section["English"].apply(lambda x: x.split())
test_section.head()["English_tokenized"]
38027    [i, m, very, serious, about, this]
3803                     [i, m, not, tired]
26924          [i, m, not, married, either]
32009      [he, s, sleeping, like, a, baby]
21339            [i, m, joking, of, course]
Name: English_tokenized, dtype: object
test_section["English_translated"] = test_section["Finnish"].apply(lambda x: translate(x, tokenized=True))
test_section.head()
English Finnish attribution English_tokenized English_translated
38027 i m very serious about this olen hyvin tosissani tasta CC-BY 2.0 (France) Attribution: tatoeba.org #2... [i, m, very, serious, about, this] [i, m, in, french]
3803 i m not tired en ole vasynyt CC-BY 2.0 (France) Attribution: tatoeba.org #1... [i, m, not, tired] [i, not, tired]
26924 i m not married either minakaan en ole naimisissa CC-BY 2.0 (France) Attribution: tatoeba.org #6... [i, m, not, married, either] [i, m, not, married, either]
32009 he s sleeping like a baby han nukkuu kuin pikkuvauva CC-BY 2.0 (France) Attribution: tatoeba.org #2... [he, s, sleeping, like, a, baby] [he, is, as, a, pianist]
21339 i m joking of course se oli vitsi tietenkin CC-BY 2.0 (France) Attribution: tatoeba.org #2... [i, m, joking, of, course] [i, m, joking, of, course]
candidate_corpus = test_section["English_translated"].values
references_corpus = test_section["English_tokenized"].values.tolist()
x = candidate_corpus.tolist()
y = [[el] for el in references_corpus]
#print(references_corpus[:5])
#print(candidate_corpus[:5])
y[:5]
[[['i', 'm', 'very', 'serious', 'about', 'this']],
 [['i', 'm', 'not', 'tired']],
 [['i', 'm', 'not', 'married', 'either']],
 [['he', 's', 'sleeping', 'like', 'a', 'baby']],
 [['i', 'm', 'joking', 'of', 'course']]]
from torchtext.data.metrics import bleu_score

bleu_score(x, y)
0.5885258316993713