Kaggle competition: Jigsaw Unintended Bias in Toxicity Classification
<SOS> metric: JigsawBiasAUC Kaggle data source: jigsaw-unintended-bias-in-toxicity-classification<feature_engineering>
%reload_ext autoreload
%autoreload 2
%matplotlib inline
test_data['Cabin'] = words<count_values>
import numpy as np
import pandas as pd
import os
import time
import gc
import random
from tqdm._tqdm_notebook import tqdm_notebook as tqdm
from keras.preprocessing import text, sequence
import torch
from torch import nn
from torch.utils import data
from torch.nn import functional as F
test_data['Cabin'].value_counts()<count_missing_values>
def seed_everything(seed=1234):
random.seed(seed)
 os.environ['PYTHONHASHSEED'] = str(seed)
 np.random.seed(seed)
 torch.manual_seed(seed)
 torch.cuda.manual_seed(seed)
 torch.backends.cudnn.deterministic = True
seed_everything()
train_data['Embarked'].isna().sum()<count_values>
CRAWL_EMBEDDING_PATH = '.. /input/fasttext-crawl-300d-2m/crawl-300d-2M.vec'
GLOVE_EMBEDDING_PATH = '.. /input/glove840b300dtxt/glove.840B.300d.txt'
NUM_MODELS = 2
LSTM_UNITS = 128
DENSE_HIDDEN_UNITS = 4 * LSTM_UNITS
MAX_LEN = 220
train_data['Embarked'].value_counts()<drop_column>
def get_coefs(word, *arr):
return word, np.asarray(arr, dtype='float32')
 def load_embeddings(path):
with open(path)as f:
return dict(get_coefs(*line.strip().split(' ')) for line in tqdm(f))
def build_matrix(word_index, path):
embedding_index = load_embeddings(path)
 embedding_matrix = np.zeros(( len(word_index)+ 1, 300))
unknown_words = []
for word, i in word_index.items() :
try:
embedding_matrix[i] = embedding_index[word]
except KeyError:
unknown_words.append(word)
 return embedding_matrix, unknown_words
for d in df:
d['Embarked'].fillna('S',inplace=True )<count_missing_values>
def sigmoid(x):
return 1 /(1 + np.exp(-x))
def train_model(learn,test,output_dim,lr=0.001,
batch_size=1024, n_epochs=4,
enable_checkpoint_ensemble=True):
all_test_preds = []
checkpoint_weights = [2 ** epoch for epoch in range(n_epochs)]
test_loader = torch.utils.data.DataLoader(test, batch_size=batch_size, shuffle=False)
 n = len(learn.data.train_dl)
 phases = [(TrainingPhase(n ).schedule_hp('lr', lr *(0.6**(i)))) for i in range(n_epochs)]
sched = GeneralScheduler(learn, phases)
 learn.callbacks.append(sched)
 for epoch in range(n_epochs):
learn.fit(1)
 test_preds = np.zeros(( len(test), output_dim))
for i, x_batch in enumerate(test_loader):
X = x_batch[0].cuda()
y_pred = sigmoid(learn.model(X ).detach().cpu().numpy())
 test_preds[i * batch_size:(i+1)* batch_size, :] = y_pred
all_test_preds.append(test_preds)
 if enable_checkpoint_ensemble:
test_preds = np.average(all_test_preds, weights=checkpoint_weights, axis=0)
 else:
test_preds = all_test_preds[-1]
return test_preds
train_data.isna().sum()<data_type_conversions>
class SpatialDropout(nn.Dropout2d):
def forward(self, x):
x = x.unsqueeze(2)
 x = x.permute(0, 3, 2, 1)
 x = super(SpatialDropout, self ).forward(x)
 x = x.permute(0, 3, 2, 1)
 x = x.squeeze(2)
 return x
class NeuralNet(nn.Module):
def __init__(self, embedding_matrix, num_aux_targets):
super(NeuralNet, self ).__init__()
embed_size = embedding_matrix.shape[1]
self.embedding = nn.Embedding(max_features, embed_size)
 self.embedding.weight = nn.Parameter(torch.tensor(embedding_matrix, dtype=torch.float32))
self.embedding.weight.requires_grad = False
self.embedding_dropout = SpatialDropout(0.3)
 self.lstm1 = nn.LSTM(embed_size, LSTM_UNITS, bidirectional=True, batch_first=True)
 self.lstm2 = nn.LSTM(LSTM_UNITS * 2, LSTM_UNITS, bidirectional=True, batch_first=True)
 self.linear1 = nn.Linear(DENSE_HIDDEN_UNITS, DENSE_HIDDEN_UNITS)
 self.linear2 = nn.Linear(DENSE_HIDDEN_UNITS, DENSE_HIDDEN_UNITS)
 self.linear_out = nn.Linear(DENSE_HIDDEN_UNITS, 1)
 self.linear_aux_out = nn.Linear(DENSE_HIDDEN_UNITS, num_aux_targets)
 def forward(self, x):
h_embedding = self.embedding(x)
 h_embedding = self.embedding_dropout(h_embedding)
 h_lstm1, _ = self.lstm1(h_embedding)
 h_lstm2, _ = self.lstm2(h_lstm1)
 avg_pool = torch.mean(h_lstm2, 1)
 max_pool, _ = torch.max(h_lstm2, 1)
 h_conc = torch.cat(( max_pool, avg_pool), 1)
 h_conc_linear1 = F.relu(self.linear1(h_conc))
h_conc_linear2 = F.relu(self.linear2(h_conc))
hidden = h_conc + h_conc_linear1 + h_conc_linear2
result = self.linear_out(hidden)
 aux_result = self.linear_aux_out(hidden)
 out = torch.cat([result, aux_result], 1)
 return out
for d in df:
d['Fare'].fillna(d['Fare'].mean() ,inplace = True )<count_missing_values>
train = pd.read_csv('.. /input/jigsaw-unintended-bias-in-toxicity-classification/train.csv')
 test = pd.read_csv('.. /input/jigsaw-unintended-bias-in-toxicity-classification/test.csv' )
test_data.isna().sum()<feature_engineering>
x_train = preprocess(train['comment_text'])
 y_aux_train = train[['target', 'severe_toxicity', 'obscene', 'identity_attack', 'insult', 'threat']]
x_test = preprocess(test['comment_text'])
 identity_columns = [
'male', 'female', 'homosexual_gay_or_lesbian', 'christian', 'jewish',
'muslim', 'black', 'white', 'psychiatric_or_mental_illness']
weights = np.ones(( len(x_train),)) / 4
weights +=(train[identity_columns].fillna(0 ).values>=0.5 ).sum(axis=1 ).astype(bool ).astype(np.int)/ 4
weights +=(((train['target'].values>=0.5 ).astype(bool ).astype(np.int)+ 
(train[identity_columns].fillna(0 ).values<0.5 ).sum(axis=1 ).astype(bool ).astype(np.int)) > 1 ).astype(bool ).astype(np.int)/ 4
weights +=(((train['target'].values<0.5 ).astype(bool ).astype(np.int)+ 
(train[identity_columns].fillna(0 ).values>=0.5 ).sum(axis=1 ).astype(bool ).astype(np.int)) > 1 ).astype(bool ).astype(np.int)/ 4
loss_weight = 1.0 / weights.mean()
train_data['Family'] = train_data.apply(lambda x: x['SibSp'] + x['Parch'], axis = 1)
 test_data['Family'] = test_data.apply(lambda x: x['SibSp'] + x['Parch'], axis = 1 )<drop_column>
y_train = np.vstack([(train['target'].values>=0.5 ).astype(np.int),weights] ).T
train_data.drop(['SibSp','Name','Ticket','Parch'], axis = 1,inplace = True)
 test_data.drop(['SibSp','Name','Ticket','Parch'], axis = 1, inplace = True )<categorify>
max_features = None
train_df = pd.get_dummies(train_data)
 test_df = pd.get_dummies(test_data )<drop_column>
tokenizer = text.Tokenizer()
tokenizer.fit_on_texts(list(x_train)+ list(x_test))
x_train = tokenizer.texts_to_sequences(x_train)
 x_test = tokenizer.texts_to_sequences(x_test)
 x_train = sequence.pad_sequences(x_train, maxlen=MAX_LEN)
 x_test = sequence.pad_sequences(x_test, maxlen=MAX_LEN )
train_df.drop('PassengerId', axis = 1, inplace = True )<prepare_x_and_y>
max_features = max_features or len(tokenizer.word_index)+ 1
max_features
y = train_df['Survived']
train_df.drop('Survived', axis=1, inplace = True)
 train_df.drop('Cabin_T', axis=1, inplace = True)
 test_df.drop('PassengerId',axis=1, inplace=True)
 X = train_df
X_test = test_df<choose_model_class>
crawl_matrix, unknown_words_crawl = build_matrix(tokenizer.word_index, CRAWL_EMBEDDING_PATH)
 print('n unknown words(crawl): ', len(unknown_words_crawl))
rfc = RandomForestClassifier()<define_search_space>
glove_matrix, unknown_words_glove = build_matrix(tokenizer.word_index, GLOVE_EMBEDDING_PATH)
 print('n unknown words(glove): ', len(unknown_words_glove))
param_grid = {
'n_estimators':[200,500,1000],
'max_features':['auto'],
'max_depth': [6, 7, 8],
'criterion': ['entropy']
}<train_on_grid>
embedding_matrix = np.concatenate([crawl_matrix, glove_matrix], axis=-1)
 embedding_matrix.shape
del crawl_matrix
del glove_matrix
gc.collect()
CV = GridSearchCV(estimator = rfc, param_grid = param_grid, cv=5)
 CV.fit(X,y)
 CV.best_estimator_<choose_model_class>
x_train_torch = torch.tensor(x_train, dtype=torch.long)
 y_train_torch = torch.tensor(np.hstack([y_train, y_aux_train]), dtype=torch.float32 )
rfc = RandomForestClassifier(criterion='entropy', max_depth=8, n_estimators=200)
 ada = AdaBoostClassifier()
gbc = GradientBoostingClassifier()<train_model>
x_test_torch = torch.tensor(x_test, dtype=torch.long )
rfc.fit(X,y)
 ada.fit(X,y)
 gbc.fit(X,y )<choose_model_class>
batch_size = 1024
train_dataset = data.TensorDataset(x_train_torch, y_train_torch)
 valid_dataset = data.TensorDataset(x_train_torch[:batch_size], y_train_torch[:batch_size])
 test_dataset = data.TensorDataset(x_test_torch)
 train_loader = torch.utils.data.DataLoader(train_dataset, batch_size=batch_size, shuffle=True)
 valid_loader = torch.utils.data.DataLoader(valid_dataset, batch_size=batch_size, shuffle=False)
 databunch = DataBunch(train_dl=train_loader,valid_dl=valid_loader )
model = StackingCVClassifier(classifiers =(rfc,ada,gbc),
meta_classifier = rfc,
use_features_in_secondary = True )<train_model>
def custom_loss(data, targets):

 bce_loss_1 = nn.BCEWithLogitsLoss(weight=targets[:,1:2] )(data[:,:1],targets[:,:1])
 bce_loss_2 = nn.BCEWithLogitsLoss()(data[:,1:],targets[:,2:])
 return(bce_loss_1 * loss_weight)+ math.sqrt(bce_loss_2 )
model.fit(X.values,y )<compute_test_metric>
all_test_preds = []
for model_idx in range(NUM_MODELS):
print('Model ', model_idx)
 seed_everything(1234 + model_idx)
 model = NeuralNet(embedding_matrix, y_aux_train.shape[-1])
 learn = Learner(databunch,model,loss_func=custom_loss)
 test_preds = train_model(learn,test_dataset,output_dim=7)
 all_test_preds.append(test_preds )
<predict_on_test><EOS> 
submission = pd.DataFrame.from_dict({
'id': test['id'],
'prediction': np.mean(all_test_preds, axis=0)[:, 0]
})
 submission.to_csv('submission.csv', index=False )