Kaggle competition: Otto Group Product Classification Challenge
<SOS> metric: MulticlassLoss Kaggle data source: otto-group-product-classification-challenge<feature_engineering>
%matplotlib inline
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=f'.. /input/{roberta_folder}/vocab.json',
merges_file=f'.. /input/{roberta_folder}/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>
train_base = pd.read_csv('.. /input/otto-group-product-classification-challenge/train.csv')
 test_base = pd.read_csv('.. /input/otto-group-product-classification-challenge/test.csv')
 sample_submit = pd.read_csv('.. /input/otto-group-product-classification-challenge/sampleSubmission.csv' )
class TweetModel(nn.Module):
def __init__(self):
super(TweetModel, self ).__init__()
config = RobertaConfig.from_pretrained(
 f'.. /input/{roberta_folder}/config.json', output_hidden_states=True)
 self.roberta = RobertaModel.from_pretrained(
 f'.. /input/{roberta_folder}/pytorch_model.bin', config=config)
 self.dropout = nn.Dropout(0.15)
 self.fc = nn.Linear(config.hidden_size, 2)
 nn.init.normal_(self.fc.weight, std=0.02)
 nn.init.normal_(self.fc.bias, 0)
 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]])
 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>
oof_lgb = pd.read_csv(".. /input/otto-simple-lgb/oof_lgb.csv")
 oof_nn = pd.read_csv(".. /input/otto-simple-nn/oof_nn.csv")
 oof_knn = pd.read_csv(".. /input/otto-knn/oof_knn.csv")
 test_lgb = pd.read_csv(".. /input/otto-simple-lgb/submit_lgb.csv")
 test_nn = pd.read_csv(".. /input/otto-simple-nn/submit_nn.csv")
 test_knn = pd.read_csv(".. /input/otto-knn/submit_knn.csv" )
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>
train = pd.concat([oof_lgb, oof_nn, oof_knn, train_base], axis=1)
 test = pd.concat([test_lgb, test_nn, test_knn, test_base], axis=1 )
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>
train['target'] = train['target'].str.replace('Class_', '')
 train['target'] = train['target'].astype(int)- 1
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>
NFOLDS = 5
RANDOM_STATE = 871975
excluded_column = ['target', 'id']
cols = [c for c in train.columns if c not in(excluded_column + [])]
folds = StratifiedKFold(n_splits=NFOLDS, shuffle=True,
random_state=RANDOM_STATE)
num_epochs = 2
batch_size = 32
skf = StratifiedKFold(n_splits=5, shuffle=True, random_state=seed )<load_from_csv>
params = {
'bagging_freq': 5, 'bagging_fraction': 0.8, 'boost_from_average':'false', 'boost': 'gbdt',
'feature_fraction': 0.3, 'learning_rate': 0.05, 'max_depth': -1, 'metrics':'multi_logloss',
'min_data_in_leaf': 10, 'min_sum_hessian_in_leaf': 8.0,'num_leaves': 8, 'num_threads': 8,
'tree_learner': 'serial', 'objective': 'multiclass', 'num_class': 9, 'verbosity': 1
}
%%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>
y_pred_lgb = np.zeros(( len(test), 9))
oof = np.zeros(( len(train), 9))
score = 0
feature_importance_df = pd.DataFrame()
valid_predict = []
for fold_n,(train_index, valid_index)in enumerate(folds.split(train, y = train['target'])) :
print('Fold', fold_n)
 X_train, X_valid = train.iloc[train_index], train.iloc[valid_index]
y_train, y_valid = X_train['target'].astype(int), X_valid['target'].astype(int)
 train_data = lgb.Dataset(X_train[cols], label=y_train)
 valid_data = lgb.Dataset(X_valid[cols], label=y_valid)
 best_params = {}
tuning_history = []
lgb_model = lgb.train(params,train_data,num_boost_round=30000,
valid_sets = [train_data, valid_data],verbose_eval=300,early_stopping_rounds = 300)
 y_valid_predict = lgb_model.predict(X_valid[cols], num_iteration=lgb_model.best_iteration)
 score += log_loss(y_valid, y_valid_predict)
 oof[valid_index] = y_valid_predict
print('Fold', fold_n, 'valid logloss', log_loss(y_valid, y_valid_predict))
y_pred_lgb += lgb_model.predict(test[cols], num_iteration=lgb_model.best_iteration)/NFOLDS
fold_importance_df = pd.DataFrame()
fold_importance_df["feature"] = cols
fold_importance_df["importance"] = lgb_model.feature_importance(importance_type='gain')
 fold_importance_df["fold"] = fold_n + 1
feature_importance_df = pd.concat([feature_importance_df, fold_importance_df], axis=0)
 print('valid logloss average:', score/NFOLDS )
%%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>
sample_submit = pd.read_csv('.. /input/otto-group-product-classification-challenge/sampleSubmission.csv')
 submit = pd.concat([sample_submit[['id']], pd.DataFrame(y_pred_lgb)], axis = 1)
 submit.columns = sample_submit.columns
submit.to_csv('submit.csv', index=False )
<import_modules><EOS> 
column_name = ['stack_lgb_' + str(i)for i in range(9)]
pd.DataFrame(oof, columns = column_name ).to_csv('oof_lgb.csv', index=False)
 pd.DataFrame(y_pred_test, columns = column_name ).to_csv('submit_lgb.csv', index=False )