Kaggle competition: Jigsaw Multilingual Toxic Comment Classification
<SOS> metric: AUC Kaggle data source: jigsaw-multilingual-toxic-comment-classification<save_to_csv>
import os
import numpy as np
import pandas as pd
import tensorflow as tf
from tensorflow.keras.layers import Dense, Input
from tensorflow.keras.optimizers import Adam
from tensorflow.keras.models import Model
from tensorflow.keras.callbacks import ModelCheckpoint
from kaggle_datasets import KaggleDatasets
import transformers
from transformers import TFAutoModel, AutoTokenizer
from tqdm.notebook import tqdm
from tokenizers import Tokenizer, models, pre_tokenizers, decoders, processors
sample_submission.to_csv('submission.csv', index=False )<define_variables>
def fast_encode(texts, tokenizer, chunk_size=256, maxlen=512):

 tokenizer.enable_truncation(max_length=maxlen)
 tokenizer.enable_padding(max_length=maxlen)
 all_ids = []
for i in tqdm(range(0, len(texts), chunk_size)) :
text_chunk = texts[i:i+chunk_size].tolist()
encs = tokenizer.encode_batch(text_chunk)
 all_ids.extend([enc.ids for enc in encs])
 return np.array(all_ids )
on_kaggle_server = os.path.exists('/kaggle')
 nq_test_file = '.. /input/tensorflow2-question-answering/simplified-nq-test.jsonl'
nq_train_file = '.. /input/tensorflow2-question-answering/simplified-nq-train.jsonl'
public_dataset = os.path.getsize(nq_test_file)<20_000_000
private_dataset = os.path.getsize(nq_test_file)>=20_000_000<load_pretrained>
def regular_encode(texts, tokenizer, maxlen=512):
enc_di = tokenizer.batch_encode_plus(
 texts,
return_attention_masks=False,
return_token_type_ids=False,
pad_to_max_length=True,
max_length=maxlen 
)
 return np.array(enc_di['input_ids'] )
if True:
importlib.reload(bert_utils )<load_from_disk>
def build_model(transformer, max_len=512):

 input_word_ids = Input(shape=(max_len,), dtype=tf.int32, name="input_word_ids")
 sequence_output = transformer(input_word_ids)[0]
cls_token = sequence_output[:, 0, :]
out = Dense(1, activation='sigmoid' )(cls_token)
 model = Model(inputs=input_word_ids, outputs=out)
 model.compile(Adam(lr=1e-5), loss='binary_crossentropy', metrics=['accuracy'])
 return model
with open('.. /input/bert-joint-baseline/bert_config.json','r')as f:
config = json.load(f)
 print(json.dumps(config,indent=4)) 
<choose_model_class>
try:
tpu = tf.distribute.cluster_resolver.TPUClusterResolver()
print('Running on TPU ', tpu.master())
 except ValueError:
tpu = None
if tpu:
tf.config.experimental_connect_to_cluster(tpu)
 tf.tpu.experimental.initialize_tpu_system(tpu)
 strategy = tf.distribute.experimental.TPUStrategy(tpu)
 else:
strategy = tf.distribute.get_strategy()
print("REPLICAS: ", strategy.num_replicas_in_sync )
class TDense(tf.keras.layers.Layer):
def __init__(self,
output_size,
kernel_initializer=None,
bias_initializer="zeros",
**kwargs):
super().__init__(**kwargs)
 self.output_size = output_size
self.kernel_initializer = kernel_initializer
self.bias_initializer = bias_initializer
def build(self,input_shape):
dtype = tf.as_dtype(self.dtype or tf.keras.backend.floatx())
 if not(dtype.is_floating or dtype.is_complex):
raise TypeError("Unable to build `TDense` layer with "
"non-floating point(and non-complex)"
"dtype %s" %(dtype,))
input_shape = tf.TensorShape(input_shape)
 if tf.compat.dimension_value(input_shape[-1])is None:
raise ValueError("The last dimension of the inputs to "
"`TDense` should be defined."
"Found `None`.")
 last_dim = tf.compat.dimension_value(input_shape[-1])
 self.input_spec = tf.keras.layers.InputSpec(min_ndim=3, axes={-1: last_dim})
 self.kernel = self.add_weight(
 "kernel",
shape=[self.output_size,last_dim],
initializer=self.kernel_initializer,
dtype=self.dtype,
trainable=True)
 self.bias = self.add_weight(
 "bias",
shape=[self.output_size],
initializer=self.bias_initializer,
dtype=self.dtype,
trainable=True)
 super(TDense, self ).build(input_shape)
 def call(self,x):
return tf.matmul(x,self.kernel,transpose_b=True)+self.bias
def mk_model(config):
seq_len = config['max_position_embeddings']
unique_id = tf.keras.Input(shape=(1,),dtype=tf.int64,name='unique_id')
 input_ids = tf.keras.Input(shape=(seq_len,),dtype=tf.int32,name='input_ids')
 input_mask = tf.keras.Input(shape=(seq_len,),dtype=tf.int32,name='input_mask')
 segment_ids = tf.keras.Input(shape=(seq_len,),dtype=tf.int32,name='segment_ids')
 BERT = modeling.BertModel(config=config,name='bert')
 pooled_output, sequence_output = BERT(input_word_ids=input_ids,
input_mask=input_mask,
input_type_ids=segment_ids)
 logits = TDense(2,name='logits' )(sequence_output)
 start_logits,end_logits = tf.split(logits,axis=-1,num_or_size_splits= 2,name='split')
 start_logits = tf.squeeze(start_logits,axis=-1,name='start_squeeze')
 end_logits = tf.squeeze(end_logits, axis=-1,name='end_squeeze')
 ans_type = TDense(5,name='ans_type' )(pooled_output)
 return tf.keras.Model([input_ for input_ in [unique_id,input_ids,input_mask,segment_ids]
if input_ is not None],
[unique_id,start_logits,end_logits,ans_type],
name='bert-baseline' )<define_variables>
AUTO = tf.data.experimental.AUTOTUNE
GCS_DS_PATH = KaggleDatasets().get_gcs_path()
EPOCHS = 2
BATCH_SIZE = 16 * strategy.num_replicas_in_sync
MAX_LEN = 192
MODEL = 'jplu/tf-xlm-roberta-large'
small_config = config.copy()
small_config['vocab_size']=16
small_config['hidden_size']=64
small_config['max_position_embeddings'] = 32
small_config['num_hidden_layers'] = 4
small_config['num_attention_heads'] = 4
small_config['intermediate_size'] = 256
small_config<categorify>
tokenizer = AutoTokenizer.from_pretrained(MODEL )
model= mk_model(config )<choose_model_class>
train1 = pd.read_csv("/kaggle/input/jigsaw-multilingual-toxic-comment-classification/jigsaw-toxic-comment-train.csv")
 train2 = pd.read_csv("/kaggle/input/jigsaw-multilingual-toxic-comment-classification/jigsaw-unintended-bias-train.csv")
 train2.toxic = train2.toxic.round().astype(int)
 valid = pd.read_csv('/kaggle/input/jigsaw-multilingual-toxic-comment-classification/validation.csv')
 test = pd.read_csv('/kaggle/input/jigsaw-multilingual-toxic-comment-classification/test.csv')
 sub = pd.read_csv('/kaggle/input/jigsaw-multilingual-toxic-comment-classification/sample_submission.csv' )
class DummyObject:
def __init__(self,**kwargs):
self.__dict__.update(kwargs)
 FLAGS=DummyObject(skip_nested_contexts=True,
max_position=50,
max_contexts=48,
max_query_length=64,
max_seq_length=512,
doc_stride=128,
include_unknowns=-1.0,
n_best_size=20,
max_answer_length=30 )<feature_engineering>
train = pd.concat([
train1[['comment_text', 'toxic']],
train2[['comment_text', 'toxic']].query('toxic==1'),
train2[['comment_text', 'toxic']].query('toxic==0' ).sample(n=100000, random_state=0)
 ] )
eval_records = ".. /input/bert-joint-baseline/nq-test.tfrecords"
if on_kaggle_server and private_dataset:
eval_records='nq-test.tfrecords'
if not os.path.exists(eval_records):
eval_writer = bert_utils.FeatureWriter(
 filename=os.path.join(eval_records),
is_training=False)
 tokenizer = tokenization.FullTokenizer(vocab_file='.. /input/bert-joint-baseline/vocab-nq.txt',
do_lower_case=True)
 features = []
convert = bert_utils.ConvertExamples2Features(tokenizer=tokenizer,
is_training=False,
output_fn=eval_writer.process_feature,
collect_stat=False)
 n_examples = 0
tqdm_notebook= tqdm.tqdm_notebook if not on_kaggle_server else None
for examples in bert_utils.nq_examples_iter(input_file=nq_test_file,
is_training=False,
tqdm=tqdm_notebook):
for example in examples:
n_examples += convert(example)
 eval_writer.close()
print('number of test examples: %d, written to file: %d' %(n_examples,eval_writer.num_features))<categorify>
%%time
x_train = regular_encode(train.comment_text.values, tokenizer, maxlen=MAX_LEN)
 x_valid = regular_encode(valid.comment_text.values, tokenizer, maxlen=MAX_LEN)
 x_test = regular_encode(test.content.values, tokenizer, maxlen=MAX_LEN)
 y_train = train.toxic.values
y_valid = valid.toxic.values
seq_length = FLAGS.max_seq_length
name_to_features = {
"unique_id": tf.io.FixedLenFeature([], tf.int64),
"input_ids": tf.io.FixedLenFeature([seq_length], tf.int64),
"input_mask": tf.io.FixedLenFeature([seq_length], tf.int64),
"segment_ids": tf.io.FixedLenFeature([seq_length], tf.int64),
}
def _decode_record(record, name_to_features=name_to_features):

 example = tf.io.parse_single_example(serialized=record, features=name_to_features)
 for name in list(example.keys()):
t = example[name]
if name != 'unique_id':
t = tf.cast(t, dtype=tf.int32)
 example[name] = t
return example
def _decode_tokens(record):
return tf.io.parse_single_example(serialized=record,
features={
"unique_id": tf.io.FixedLenFeature([], tf.int64),
"token_map" : tf.io.FixedLenFeature([seq_length], tf.int64)
 })
<categorify>
train_dataset =(
 tf.data.Dataset 
.from_tensor_slices(( x_train, y_train)) 
.repeat() 
.shuffle(2048)
.batch(BATCH_SIZE)
.prefetch(AUTO)
)
 valid_dataset =(
 tf.data.Dataset 
.from_tensor_slices(( x_valid, y_valid)) 
.batch(BATCH_SIZE)
.cache() 
.prefetch(AUTO)
)
 test_dataset =(
 tf.data.Dataset 
.from_tensor_slices(x_test)
.batch(BATCH_SIZE)
 )
raw_ds = tf.data.TFRecordDataset(eval_records)
 token_map_ds = raw_ds.map(_decode_tokens)
 decoded_ds = raw_ds.map(_decode_record)
 ds = decoded_ds.batch(batch_size=16,drop_remainder=False )<predict_on_test>
%%time
with strategy.scope() :
transformer_layer = TFAutoModel.from_pretrained(MODEL)
 model = build_model(transformer_layer, max_len=MAX_LEN)
 model.summary()
result=model.predict_generator(ds,verbose=1 )<load_pretrained>
n_steps = x_train.shape[0] // BATCH_SIZE
train_history = model.fit(
 train_dataset,
steps_per_epoch=n_steps,
validation_data=valid_dataset,
epochs=EPOCHS
)
np.savez_compressed('bert-joint-baseline-output.npz',
**dict(zip(['uniqe_id','start_logits','end_logits','answer_type_logits'],
result)) )<create_dataframe>
n_steps = x_valid.shape[0] // BATCH_SIZE
train_history_2 = model.fit(
 valid_dataset.repeat() ,
steps_per_epoch=n_steps,
epochs=EPOCHS
)
<import_modules><EOS> 
sub['toxic'] = model.predict(test_dataset, verbose=1)
 sub.to_csv('submission.csv', index=False )