Kaggle competition: Tweet Sentiment Extraction
<SOS> metric: Jaccard Kaggle data source: tweet-sentiment-extraction<split>
print('TF version',tf.__version__ )
train_arrays, test_arrays, train_labels, test_labels = train_test_split(X_train,
y_train,
random_state =42,
test_size=0.20 )<train_on_grid>
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 
)
 sentiment_id = {'positive': 1313, 'negative': 2430, 'neutral': 7974}
train = pd.read_csv('.. /input/tweet-sentiment-extraction/train.csv' ).fillna('')
 train.head()
def svc_param_selection(X, y, nfolds):
Cs = [1.07]
gammas = [2.075]
param_grid = {'C': Cs, 'gamma' : gammas}
grid_search = GridSearchCV(SVC(kernel='rbf'), param_grid, cv=nfolds, n_jobs=8)
 grid_search.fit(X, y)
 grid_search.best_params_
return grid_search
model = svc_param_selection(train_arrays,train_labels, 5 )<predict_on_test>
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')
 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)
 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)+5] = [0] + enc.ids + [2,2] + [s_tok] + [2]
attention_mask[k,:len(enc.ids)+5] = 1
if len(toks)>0:
start_tokens[k,toks[0]+1] = 1
end_tokens[k,toks[-1]+1] = 1
pred = model.predict(test_arrays)
<compute_test_metric>
test = pd.read_csv('.. /input/tweet-sentiment-extraction/test.csv' ).fillna('')
 ct = test.shape[0]
input_ids_t = np.ones(( ct,MAX_LEN),dtype='int32')
 attention_mask_t = np.zeros(( ct,MAX_LEN),dtype='int32')
 token_type_ids_t = np.zeros(( ct,MAX_LEN),dtype='int32')
 for k in range(test.shape[0]):
text1 = " "+" ".join(test.loc[k,'text'].split())
 enc = tokenizer.encode(text1)
 s_tok = sentiment_id[test.loc[k,'sentiment']]
input_ids_t[k,:len(enc.ids)+5] = [0] + enc.ids + [2,2] + [s_tok] + [2]
attention_mask_t[k,:len(enc.ids)+5] = 1
accuracy = accuracy_score(test_labels,pred)
 accuracy 
<train_on_grid>
def build_model() :
ids = tf.keras.layers.Input(( MAX_LEN,), dtype=tf.int32)
 att = tf.keras.layers.Input(( MAX_LEN,), dtype=tf.int32)
 tok = tf.keras.layers.Input(( MAX_LEN,), dtype=tf.int32)
 config = RobertaConfig.from_pretrained(PATH+'config-roberta-base.json')
 bert_model = TFRobertaModel.from_pretrained(PATH+'pretrained-roberta-base.h5',config=config)
 x = bert_model(ids,attention_mask=att,token_type_ids=tok)
 x1 = tf.keras.layers.Dropout(0.1 )(x[0])
 x1 = tf.keras.layers.Conv1D(1,1 )(x1)
 x1 = tf.keras.layers.Flatten()(x1)
 x1 = tf.keras.layers.Activation('softmax' )(x1)
 x2 = tf.keras.layers.Dropout(0.1 )(x[0])
 x2 = tf.keras.layers.Conv1D(1,1 )(x2)
 x2 = tf.keras.layers.Flatten()(x2)
 x2 = tf.keras.layers.Activation('softmax' )(x2)
 model = tf.keras.models.Model(inputs=[ids, att, tok], outputs=[x1,x2])
 optimizer = tf.keras.optimizers.Adam(learning_rate=0.0001)
 model.compile(loss='categorical_crossentropy', optimizer=optimizer)
 return model
model_final = svc_param_selection(X_train,y_train, 5)
<predict_on_test>
def jaccard(str1, str2):
a = set(str1.lower().split())
 b = set(str2.lower().split())
 if(len(a)==0)&(len(b)==0): return 0.5
c = a.intersection(b)
 return float(len(c)) /(len(a)+ len(b)- len(c))
pred=model_final.predict(X_test)
<count_values>
jac = []; VER='v0'; DISPLAY=1
oof_start = np.zeros(( input_ids.shape[0],MAX_LEN))
oof_end = np.zeros(( input_ids.shape[0],MAX_LEN))
preds_start = np.zeros(( input_ids_t.shape[0],MAX_LEN))
preds_end = np.zeros(( input_ids_t.shape[0],MAX_LEN))
skf = StratifiedKFold(n_splits=5,shuffle=True,random_state=777)
 for fold,(idxT,idxV)in enumerate(skf.split(input_ids,train.sentiment.values)) :
print('
print('
print('
K.clear_session()
model = build_model()
sv = tf.keras.callbacks.ModelCheckpoint(
 '%s-roberta-%i.h5'%(VER,fold), monitor='val_loss', verbose=1, save_best_only=True,
save_weights_only=True, mode='auto', save_freq='epoch')
 model.fit([input_ids[idxT,], attention_mask[idxT,], token_type_ids[idxT,]], [start_tokens[idxT,], end_tokens[idxT,]],
epochs=5, batch_size=32, verbose=DISPLAY, callbacks=[sv],
validation_data=([input_ids[idxV,],attention_mask[idxV,],token_type_ids[idxV,]],
[start_tokens[idxV,], end_tokens[idxV,]]))
print('Loading model...')
 model.load_weights('%s-roberta-%i.h5'%(VER,fold))
print('Predicting OOF...')
 oof_start[idxV,],oof_end[idxV,] = model.predict([input_ids[idxV,],attention_mask[idxV,],token_type_ids[idxV,]],verbose=DISPLAY)
 print('Predicting Test...')
 preds = model.predict([input_ids_t,attention_mask_t,token_type_ids_t],verbose=DISPLAY)
 preds_start += preds[0]/skf.n_splits
preds_end += preds[1]/skf.n_splits
all = []
for k in idxV:
a = np.argmax(oof_start[k,])
 b = np.argmax(oof_end[k,])
 if a>b:
st = train.loc[k,'text']
else:
text1 = " "+" ".join(train.loc[k,'text'].split())
 enc = tokenizer.encode(text1)
 st = tokenizer.decode(enc.ids[a-1:b])
 all.append(jaccard(st,train.loc[k,'selected_text']))
jac.append(np.mean(all))
print('>>>> FOLD %i Jaccard ='%(fold+1),np.mean(all))
print()
Counter(pred )<count_values>
print('>>>> OVERALL 5Fold CV Jaccard =',np.mean(jac))
test['pred']=pred.tolist()
test['pred']=[1 if i>=.75 else j for i,j in zip(test['hashtag_score_normalized'],test['pred'])]
test['pred']=[1 if i>=.90 else j for i,j in zip(test['keyword_score'],test['pred'])]
test.pred.value_counts() 
<save_to_csv>
all = []
for k in range(input_ids_t.shape[0]):
a = np.argmax(preds_start[k,])
 b = np.argmax(preds_end[k,])
 if a>b:
st = test.loc[k,'text']
else:
text1 = " "+" ".join(test.loc[k,'text'].split())
 enc = tokenizer.encode(text1)
 st = tokenizer.decode(enc.ids[a-1:b])
 all.append(st )
<set_options><EOS> 
test['selected_text'] = all
test[['textID','selected_text']].to_csv('submission.csv',index=False)
 pd.set_option('max_colwidth', 60)
 test.sample(25 )