Kaggle competition: Quora Question Pairs
warnings.filterwarnings('ignore' )<set_options>
df_train = pd.read_csv('.. /input/train.csv' )
def seed_everything(seed_value):
random.seed(seed_value)
 np.random.seed(seed_value)
 torch.manual_seed(seed_value)
 os.environ['PYTHONHASHSEED'] = str(seed_value)
 if torch.cuda.is_available() :
torch.cuda.manual_seed(seed_value)
 torch.cuda.manual_seed_all(seed_value)
 torch.backends.cudnn.deterministic = True
torch.backends.cudnn.benchmark = True
seed = 42
seed_everything(seed )<feature_engineering>
df_test = pd.read_csv('.. /input/test.csv' )
class TweetDataset(torch.utils.data.Dataset):
def __init__(self, df, max_len=96):
self.df = df
self.max_len = max_len
self.labeled = 'selected_text' in df
self.tokenizer = tokenizers.ByteLevelBPETokenizer(
 vocab_file='.. /input/roberta-base/vocab.json',
merges_file='.. /input/roberta-base/merges.txt',
lowercase=True,
add_prefix_space=True)
 def __getitem__(self, index):
data = {}
row = self.df.iloc[index]
ids, masks, tweet, offsets = self.get_input_data(row)
 data['ids'] = ids
data['masks'] = masks
data['tweet'] = tweet
data['offsets'] = offsets
if self.labeled:
start_idx, end_idx = self.get_target_idx(row, tweet, offsets)
 data['start_idx'] = start_idx
data['end_idx'] = end_idx
return data
def __len__(self):
return len(self.df)
 def get_input_data(self, row):
tweet = " " + " ".join(row.text.lower().split())
 encoding = self.tokenizer.encode(tweet)
 sentiment_id = self.tokenizer.encode(row.sentiment ).ids
ids = [0] + sentiment_id + [2, 2] + encoding.ids + [2]
offsets = [(0, 0)] * 4 + encoding.offsets + [(0, 0)]
pad_len = self.max_len - len(ids)
 if pad_len > 0:
ids += [1] * pad_len
offsets += [(0, 0)] * pad_len
ids = torch.tensor(ids)
 masks = torch.where(ids != 1, torch.tensor(1), torch.tensor(0))
offsets = torch.tensor(offsets)
 return ids, masks, tweet, offsets
def get_target_idx(self, row, tweet, offsets):
selected_text = " " + " ".join(row.selected_text.lower().split())
 len_st = len(selected_text)- 1
idx0 = None
idx1 = None
for ind in(i for i, e in enumerate(tweet)if e == selected_text[1]):
if " " + tweet[ind: ind+len_st] == selected_text:
idx0 = ind
idx1 = ind + len_st - 1
break
char_targets = [0] * len(tweet)
 if idx0 != None and idx1 != None:
for ct in range(idx0, idx1 + 1):
char_targets[ct] = 1
target_idx = []
for j,(offset1, offset2)in enumerate(offsets):
if sum(char_targets[offset1: offset2])> 0:
target_idx.append(j)
 start_idx = target_idx[0]
end_idx = target_idx[-1]
return start_idx, end_idx
def get_train_val_loaders(df, train_idx, val_idx, batch_size=8):
train_df = df.iloc[train_idx]
val_df = df.iloc[val_idx]
train_loader = torch.utils.data.DataLoader(
 TweetDataset(train_df),
batch_size=batch_size,
shuffle=True,
num_workers=2,
drop_last=True)
 val_loader = torch.utils.data.DataLoader(
 TweetDataset(val_df),
batch_size=batch_size,
shuffle=False,
num_workers=2)
 dataloaders_dict = {"train": train_loader, "val": val_loader}
return dataloaders_dict
def get_test_loader(df, batch_size=32):
loader = torch.utils.data.DataLoader(
 TweetDataset(df),
batch_size=batch_size,
shuffle=False,
num_workers=2)
 return loader<load_pretrained>
print('Duplicate pairs in small train: {}%'.format(round(small_train['is_duplicate'].mean() *100, 2)))
 print('Duplicate pairs in full df_train: {}%'.format(round(df_train['is_duplicate'].mean() *100, 2)) )
class TweetModel(nn.Module):
def __init__(self):
super(TweetModel, self ).__init__()
config = RobertaConfig.from_pretrained(
 '.. /input/roberta-base/config.json', output_hidden_states=True)
 self.roberta = RobertaModel.from_pretrained(
 '.. /input/roberta-base/pytorch_model.bin', config=config)
 self.dropout = nn.Dropout(0.5)
 self.fc = nn.Linear(config.hidden_size, 2)
 nn.init.normal_(self.fc.weight, std=0.02)
 nn.init.normal_(self.fc.bias, 0)
 self.relu = nn.ReLU()
def forward(self, input_ids, attention_mask):
_, _, hs = self.roberta(input_ids, attention_mask)
 x = torch.stack([hs[-1], hs[-2], hs[-3], hs[-4], hs[-5], hs[-6], hs[-7], hs[-8]])
 x = torch.mean(x, 0)
 x = self.dropout(x)
 x = self.fc(x)
 start_logits, end_logits = x.split(1, dim=-1)
 start_logits = start_logits.squeeze(-1)
 end_logits = end_logits.squeeze(-1)
 return start_logits, end_logits<compute_test_metric>
stops = set(stopwords.words("english"))
def word_match_share(row):
q1words = {}
q2words = {}
for word in str(row['question1'] ).lower().split() :
if word not in stops:
q1words[word] = 1
for word in str(row['question2'] ).lower().split() :
if word not in stops:
q2words[word] = 1
if len(q1words)== 0 or len(q2words)== 0:
return 0
shared_words_in_q1 = [w for w in q1words.keys() if w in q2words]
shared_words_in_q2 = [w for w in q2words.keys() if w in q1words]
R =(len(shared_words_in_q1)+ len(shared_words_in_q2)) /(len(q1words)+ len(q2words))
return R
train_word_match = df_train.apply(word_match_share, axis=1, raw=True )
def loss_fn(start_logits, end_logits, start_positions, end_positions):
ce_loss = nn.CrossEntropyLoss()
start_loss = ce_loss(start_logits, start_positions)
 end_loss = ce_loss(end_logits, end_positions)
 total_loss = start_loss + end_loss
return total_loss<statistical_test>
def get_weight(count, eps=1000, min_count=2):
if count < min_count:
return 0
else:
return 1 /(count + eps)
 eps = 5000
words =(" ".join(train_qs)).lower().split()
counts = Counter(words)
 weights = {word: get_weight(count)for word, count in counts.items() }
def get_selected_text(text, start_idx, end_idx, offsets):
selected_text = ""
for ix in range(start_idx, end_idx + 1):
selected_text += text[offsets[ix][0]: offsets[ix][1]]
if(ix + 1)< len(offsets)and offsets[ix][1] < offsets[ix + 1][0]:
selected_text += " "
return selected_text
def jaccard(str1, str2):
a = set(str1.lower().split())
 b = set(str2.lower().split())
 c = a.intersection(b)
 return float(len(c)) /(len(a)+ len(b)- len(c))
def compute_jaccard_score(text, start_idx, end_idx, start_logits, end_logits, offsets):
start_pred = np.argmax(start_logits)
 end_pred = np.argmax(end_logits)
 if start_pred > end_pred:
pred = text
else:
pred = get_selected_text(text, start_pred, end_pred, offsets)
 true = get_selected_text(text, start_idx, end_idx, offsets)
 return jaccard(true, pred )<train_model>
print('Most common words and weights:
')
 print(sorted(weights.items() , key=lambda x: x[1] if x[1] > 0 else 9999)[:10])
 print('
Least common words and weights: ')
(sorted(weights.items() , key=lambda x: x[1], reverse=True)[:10] )
def train_model(model, dataloaders_dict, criterion, optimizer, num_epochs, filename):
model.cuda()
for epoch in range(num_epochs):
for phase in ['train', 'val']:
if phase == 'train':
model.train()
else:
model.eval()
epoch_loss = 0.0
epoch_jaccard = 0.0
for data in(dataloaders_dict[phase]):
ids = data['ids'].cuda()
masks = data['masks'].cuda()
tweet = data['tweet']
offsets = data['offsets'].numpy()
start_idx = data['start_idx'].cuda()
end_idx = data['end_idx'].cuda()
optimizer.zero_grad()
with torch.set_grad_enabled(phase == 'train'):
start_logits, end_logits = model(ids, masks)
 loss = criterion(start_logits, end_logits, start_idx, end_idx)
 if phase == 'train':
loss.backward()
optimizer.step()
epoch_loss += loss.item() * len(ids)
 start_idx = start_idx.cpu().detach().numpy()
end_idx = end_idx.cpu().detach().numpy()
start_logits = torch.softmax(start_logits, dim=1 ).cpu().detach().numpy()
end_logits = torch.softmax(end_logits, dim=1 ).cpu().detach().numpy()
for i in range(len(ids)) :
jaccard_score = compute_jaccard_score(
 tweet[i],
start_idx[i],
end_idx[i],
start_logits[i],
end_logits[i],
offsets[i])
 epoch_jaccard += jaccard_score
epoch_loss = epoch_loss / len(dataloaders_dict[phase].dataset)
 epoch_jaccard = epoch_jaccard / len(dataloaders_dict[phase].dataset)
 print('Epoch {}/{} | {:^5} | Loss: {:.4f} | Jaccard: {:.4f}'.format(
 epoch + 1, num_epochs, phase, epoch_loss, epoch_jaccard))
torch.save(model.state_dict() , filename )<choose_model_class>
def tfidf_word_match_share(row):
q1words = {}
q2words = {}
for word in str(row['question1'] ).lower().split() :
if word not in stops:
q1words[word] = 1
for word in str(row['question2'] ).lower().split() :
if word not in stops:
q2words[word] = 1
if len(q1words)== 0 or len(q2words)== 0:
return 0
shared_weights = [weights.get(w, 0)for w in q1words.keys() if w in q2words] + [weights.get(w, 0)for w in q2words.keys() if w in q1words]
total_weights = [weights.get(w, 0)for w in q1words] + [weights.get(w, 0)for w in q2words]
R = np.sum(shared_weights)/ np.sum(total_weights)
 return R
num_epochs = 3
batch_size = 32
skf = StratifiedKFold(n_splits=3, shuffle=True, random_state=seed )<load_from_csv>
print('Original AUC:', roc_auc_score(df_train['is_duplicate'], train_word_match))
print(' TFIDF AUC:', roc_auc_score(df_train['is_duplicate'], tfidf_train_word_match.fillna(0)) )
%%time
train_df = pd.read_csv('.. /input/tweet-sentiment-extraction/train.csv')
 train_df['text'] = train_df['text'].astype(str)
 train_df['selected_text'] = train_df['selected_text'].astype(str)
 for fold,(train_idx, val_idx)in enumerate(skf.split(train_df, train_df.sentiment), start=1):
print(f'Fold: {fold}')
 model = TweetModel()
optimizer = optim.AdamW(model.parameters() , lr=3e-5, betas=(0.9, 0.999))
criterion = loss_fn
dataloaders_dict = get_train_val_loaders(train_df, train_idx, val_idx, batch_size)
 train_model(
 model,
dataloaders_dict,
criterion,
optimizer,
num_epochs,
f'roberta_fold{fold}.pth' )<load_from_csv>
train_q1s = pd.Series(df_train['question1'].tolist() ).astype(str)
 train_q2s = pd.Series(df_train['question2'].tolist() ).astype(str)
 train_q1_words = train_q1s.apply(lambda x: len(x.split(' ')))
 train_q2_words = train_q1s.apply(lambda x: len(x.split(' ')))
 train_word_count_diff=train_q1_words-train_q2_words
test_q1s = pd.Series(df_test['question1'].tolist() ).astype(str)
 test_q2s = pd.Series(df_test['question2'].tolist() ).astype(str)
 test_q1_words = test_q1s.apply(lambda x: len(x.split(' ')))
 test_q2_words = test_q2s.apply(lambda x: len(x.split(' ')))
 test_word_count_diff=test_q1_words-test_q2_words
%%time
test_df = pd.read_csv('.. /input/tweet-sentiment-extraction/test.csv')
 test_df['text'] = test_df['text'].astype(str)
 test_loader = get_test_loader(test_df)
 predictions = []
models = []
for fold in range(skf.n_splits):
model = TweetModel()
model.cuda()
model.load_state_dict(torch.load(f'roberta_fold{fold+1}.pth'))
model.eval()
models.append(model)
 for data in test_loader:
ids = data['ids'].cuda()
masks = data['masks'].cuda()
tweet = data['tweet']
offsets = data['offsets'].numpy()
start_logits = []
end_logits = []
for model in models:
with torch.no_grad() :
output = model(ids, masks)
 start_logits.append(torch.softmax(output[0], dim=1 ).cpu().detach().numpy())
 end_logits.append(torch.softmax(output[1], dim=1 ).cpu().detach().numpy())
 start_logits = np.mean(start_logits, axis=0)
 end_logits = np.mean(end_logits, axis=0)
 for i in range(len(ids)) :
start_pred = np.argmax(start_logits[i])
 end_pred = np.argmax(end_logits[i])
 if start_pred > end_pred:
pred = tweet[i]
else:
pred = get_selected_text(tweet[i], start_pred, end_pred, offsets[i])
 predictions.append(pred )<save_to_csv>
x_train = pd.DataFrame()
x_test = pd.DataFrame()
x_train['word_match'] = train_word_match
x_train['tfidf_word_match'] = tfidf_train_word_match
x_train['word_count_diff']=train_word_count_diff
x_test['word_match'] = df_test.apply(word_match_share, axis=1, raw=True)
 x_test['tfidf_word_match'] = df_test.apply(tfidf_word_match_share, axis=1, raw=True)
 x_test['word_count_diff']=train_word_count_diff
y_train = df_train['is_duplicate'].values
sub_df = pd.read_csv('.. /input/tweet-sentiment-extraction/sample_submission.csv')
 sub_df['selected_text'] = predictions
sub_df['selected_text'] = sub_df['selected_text'].apply(lambda x: x.replace('!!!!', '!')if len(x.split())==1 else x)
 sub_df['selected_text'] = sub_df['selected_text'].apply(lambda x: x.replace('.. ', '.')if len(x.split())==1 else x)
 sub_df['selected_text'] = sub_df['selected_text'].apply(lambda x: x.replace('...', '.')if len(x.split())==1 else x)
 sub_df.to_csv('submission.csv', index=False)
 sub_df.head()<feature_engineering>
pos_train = x_train[y_train == 1]
neg_train = x_train[y_train == 0]
p = 0.165
scale =(( len(pos_train)/(len(pos_train)+ len(neg_train)))/ p)- 1
while scale > 1:
neg_train = pd.concat([neg_train, neg_train])
 scale -=1
neg_train = pd.concat([neg_train, neg_train[:int(scale * len(neg_train)) ]])
 print(len(pos_train)/(len(pos_train)+ len(neg_train)))
 x_train = pd.concat([pos_train, neg_train])
 y_train =(np.zeros(len(pos_train)) + 1 ).tolist() + np.zeros(len(neg_train)).tolist()
del pos_train, neg_train
SEED = 88888
os.environ['PYTHONHASHSEED']=str(SEED)
 os.environ['TF_DETERMINISTIC_OPS'] = '1'
random.seed(SEED)
 np.random.seed(SEED)
 tf.random.set_seed(SEED)
 print('TF version',tf.__version__ )<load_from_csv>
x_train, x_valid, y_train, y_valid = train_test_split(x_train, y_train, test_size=0.2, random_state=4242 )
MAX_LEN = 96
PATH = '.. /input/tf-roberta/'
tokenizer = tokenizers.ByteLevelBPETokenizer(
 vocab_file=PATH+'vocab-roberta-base.json',
merges_file=PATH+'merges-roberta-base.txt',
lowercase=True,
add_prefix_space=True 
)
 EPOCHS = 100
BATCH_SIZE = 32
PAD_ID = 1
LABEL_SMOOTHING = 0.15
sentiment_id = {'positive': 1313, 'negative': 2430, 'neutral': 7974}
train = pd.read_csv('.. /input/tweet-sentiment-extraction/train.csv' ).fillna('')
<define_variables>
params = {}
params['objective'] = 'binary:logistic'
params['eval_metric'] = 'logloss'
params['eta'] = 0.02
params['max_depth'] = 4
d_train = xgb.DMatrix(x_train, label=y_train)
 d_valid = xgb.DMatrix(x_valid, label=y_valid)
 watchlist = [(d_train, 'train'),(d_valid, 'valid')]
bst = xgb.train(params, d_train, 400, watchlist, early_stopping_rounds=50, verbose_eval=10 )
ct = train.shape[0]
input_ids = np.ones(( ct,MAX_LEN),dtype='int32')
 attention_mask = np.zeros(( ct,MAX_LEN),dtype='int32')
 token_type_ids = np.zeros(( ct,MAX_LEN),dtype='int32')
 start_tokens = np.zeros(( ct,MAX_LEN),dtype='int32')
 end_tokens = np.zeros(( ct,MAX_LEN),dtype='int32')
 pre_enc = 4
post_enc = 1
tot_enc = pre_enc+post_enc
for k in range(train.shape[0]):
text1 = " "+" ".join(train.loc[k,'text'].split())
 text2 = " ".join(train.loc[k,'selected_text'].split())
 idx =(text1 + " " ).find(" "+ text2 + " ")
 if idx < 0:
idx = text1.find(text2)
 else:
idx += 1
chars = np.zeros(( len(text1)))
 chars[idx:idx+len(text2)]=1
if text1[idx-1]==' ': chars[idx-1] = 1
enc = tokenizer.encode(text1)
 offsets = []; idx=0
for t in enc.ids:
w = tokenizer.decode([t])
 offsets.append(( idx,idx+len(w)))
 idx += len(w)
 toks = []
for i,(a,b)in enumerate(offsets):
sm = np.sum(chars[a:b])
 if sm>0: toks.append(i)
 s_tok = sentiment_id[train.loc[k,'sentiment']]
input_ids[k,:len(enc.ids)+ tot_enc] = [0,s_tok,s_tok,2] + enc.ids + [2]
attention_mask[k,:len(enc.ids)+ tot_enc] = 1
if len(toks)>0:
start_tokens[k,toks[0]+ pre_enc ] = 1
end_tokens[k,toks[-1]+ pre_enc] = 1<load_from_csv>
d_test = xgb.DMatrix(x_test)
 p_test = bst.predict(d_test)
 sub = pd.DataFrame()
sub['test_id'] = df_test['test_id']
sub['is_duplicate'] = p_test
sub.to_csv('simple_xgb.csv', index=False )