Kaggle competition: Humpback Whale Identification
<SOS> metric: MAP@{K} Kaggle data source: humpback-whale-identification<define_variables>
!pip install fastai==0.7.0 --no-deps
!pip install torch==0.4.1 torchvision==0.2.1
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=3, 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()<feature_engineering>
MODEL_NAME = 'Resnext50'
TRAIN = '.. /input/humpback-whale-identification/train/'
TEST = '.. /input/humpback-whale-identification/test/'
LABELS = '.. /input/humpback-whale-identification/train.csv'
SAMPLE_SUB = '.. /input/humpback-whale-identification/sample_submission.csv'
arch = resnext50
num_workers = 4
print('>>>> OVERALL 5Fold CV Jaccard =',np.mean(jac))<string_transform>
df = pd.read_csv(LABELS ).set_index('Image')
 new_whale_df = df[df.Id == "new_whale"]
train_df = df[~(df.Id == "new_whale")]
unique_labels = np.unique(train_df.Id.values)
 labels_dict = dict()
labels_list = []
for i in range(len(unique_labels)) :
labels_dict[unique_labels[i]] = i
labels_list.append(unique_labels[i])
 print("Number of classes: {}".format(len(unique_labels)))
 train_df.Id = train_df.Id.apply(lambda x: labels_dict[x])
 train_labels = np.asarray(train_df.Id.values)
 test_names = [f for f in os.listdir(TEST)]
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 )<save_to_csv>
train_df['image_name'] = train_df.index
rs = np.random.RandomState(42)
 perm = rs.permutation(len(train_df))
tr_n = train_df['image_name'].values
val_n = train_df['image_name'].values[perm][:1000]
print('Train/val:', len(tr_n), len(val_n))
print('Train classes', len(train_df.loc[tr_n].Id.unique()))
print('Val classes', len(train_df.loc[val_n].Id.unique()))
test['selected_text'] = all
for i in range(test.shape[0]):
if(test['sentiment'][i] == 'neutral'):
test['selected_text'][i] = test['text'][i]
test[['textID','selected_text']].to_csv('submission.csv',index=False)
 pd.set_option('max_colwidth', 60)
 test.sample(25)
<set_options>
PICKL = '.. /input/cropimg/bounding-box.pickle'
with open(PICKL, 'rb')as f:
crop_boxs = pickle.load(f )
warnings.filterwarnings('ignore' )<set_options>
pil2tensor = transforms.ToTensor()
class HWIDataset(FilesDataset):
def __init__(self, fnames, path, transform):
self.train_df = train_df
super().__init__(fnames, transform, path)
 def get_x(self, i):
img_cr = make_bbox_image(os.path.join(self.path, self.fnames[i])).convert("RGB")
 img = pil2tensor(img_cr ).numpy().transpose(1, 2, 0)
 try:
img = cv2.resize(img,(self.sz, self.sz))
except Exception as e:
print(self.fnames[i])
 print(str(e))
return img
def get_y(self, i):
if(self.path == TEST): return 0
return self.train_df.loc[self.fnames[i]]['Id']
def get_c(self):
return len(unique_labels)
torch.cuda.is_available()<set_options>
class RandomLighting(Transform):
def __init__(self, b, c, tfm_y=TfmType.NO):
super().__init__(tfm_y)
 self.b, self.c = b, c
def set_state(self):
self.store.b_rand = rand0(self.b)
 self.store.c_rand = rand0(self.c)
 def do_transform(self, x, is_y):
if is_y and self.tfm_y != TfmType.PIXEL: return x
b = self.store.b_rand
c = self.store.c_rand
c = -1 /(c - 1)if c < 0 else c + 1
x = lighting(x, b, c)
 return x
def get_data(sz, batch_size):

 aug_tfms = [RandomRotateZoom(deg=20, zoom=2, stretch=1),
RandomLighting(0.2, 0.2, tfm_y=TfmType.NO),
RandomBlur(blur_strengths=3,tfm_y=TfmType.NO),
RandomFlip(tfm_y=TfmType.NO)]
tfms = tfms_from_model(arch, sz, crop_type=CropType.NO, tfm_y=TfmType.NO,
aug_tfms=aug_tfms)
 ds = ImageData.get_ds(HWIDataset,(tr_n[:-(len(tr_n)% batch_size)], TRAIN), 
(val_n, TRAIN), tfms, test=(test_names, TEST))
md = ImageData("./", ds, batch_size, num_workers=num_workers, classes=None)
 return md
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>
!wget http://files.fast.ai/models/weights.tgz
!tar -zxvf weights.tgz
!mkdir /opt/conda/lib/python3.6/site-packages/fastai/weights/
!cp weights/resnext_50_32x4d.pth /opt/conda/lib/python3.6/site-packages/fastai/weights/
!rm -rf weights weights.tgz
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>
image_size = 448
batch_size = 8
md = get_data(image_size, batch_size)
 extra_fc_layers_size = []
learn = ConvLearner.pretrained(arch, md, xtra_fc=extra_fc_layers_size)
 learn.opt_fn = optim.Adam
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)
 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>
md.is_multi, md.is_reg
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>
print('Number of layer groups:', len(learn.get_layer_groups()), '\t(first 2 groups is pretrained backbone)')
 print('This is our extra thin on top of the backbone Resnet50 architecture:')
 learn.get_layer_groups() [2]
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>
base_lr = 1e-4
fc_lr = 1e-3
lrs = [base_lr, base_lr, fc_lr]
learn.fit(lrs=lrs, n_cycle=2, cycle_len=None)
 learn.unfreeze()
learn.fit(lrs, n_cycle=9, cycle_len=None)
 learn.save(MODEL_PATH )
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>
best_th = 0.4
num_epochs = 3
batch_size = 32
skf = StratifiedKFold(n_splits=10, shuffle=True, random_state=seed )<load_from_csv>
preds_t,y_t = learn.TTA(is_test=True,n_aug=8)
 preds_t = np.stack(preds_t, axis=-1)
 preds_t = np.exp(preds_t)
 preds_t = preds_t.mean(axis=-1)
 preds_t = np.concatenate([np.zeros(( preds_t.shape[0],1)) +best_th, preds_t],axis=1)
 np.save("rx50_480_preds.npy",preds_t )
<load_from_csv><EOS> 
sample_df = pd.read_csv(SAMPLE_SUB)
 sample_list = list(sample_df.Image)
 labels_list = ["new_whale"]+labels_list
pred_list = [[labels_list[i] for i in p.argsort() [-5:][::-1]] for p in preds_t]
pred_dic = dict(( key, value)for(key, value)in zip(learn.data.test_ds.fnames,pred_list))
pred_list_cor = [' '.join(pred_dic[id])for id in sample_list]
df = pd.DataFrame({'Image':sample_list,'Id': pred_list_cor})
 df.to_csv('submission_{}.csv'.format(MODEL_NAME), header=True, index=False)
 df.head()