Kaggle competition: Severstal: Steel Defect Detection
train_lectures = train_df[train_df.content_type_id == True].merge(lectures_df, left_on='content_id', right_on='lecture_id', how='left' )<groupby>
warnings.filterwarnings('ignore')
user_lecture_stats_part = train_lectures.groupby('user_id',as_index = False)[part_lectures_columns + types_of_lectures_columns].sum()<data_type_conversions>
unet_se_resnext50_32x4d = \
load('/kaggle/input/severstalmodels/unet_se_resnext50_32x4d.pth' ).cuda()
unet_mobilenet2 = load('/kaggle/input/severstalmodels/unet_mobilenet2.pth' ).cuda()
unet_resnet34 = load('/kaggle/input/severstalmodels/unet_resnet34.pth' ).cuda()
lecturedata_types_dict = {
'user_id': 'int32',
'part_1': 'int8',
'part_2': 'int8',
'part_3': 'int8',
'part_4': 'int8',
'part_5': 'int8',
'part_6': 'int8',
'part_7': 'int8',
'type_of_concept': 'int8',
'type_of_intention': 'int8',
'type_of_solving_question': 'int8',
'type_of_starter': 'int8'
}
user_lecture_stats_part = user_lecture_stats_part.astype(lecturedata_types_dict )<data_type_conversions>
class Model:
def __init__(self, models):
self.models = models
def __call__(self, x):
res = []
x = x.cuda()
with torch.no_grad() :
for m in self.models:
res.append(m(x))
res = torch.stack(res)
 return torch.mean(res, dim=0)
 model = Model([unet_se_resnext50_32x4d, unet_mobilenet2, unet_resnet34] )
for column in user_lecture_stats_part.columns:
if(column !='user_id'):
user_lecture_stats_part[column] =(user_lecture_stats_part[column] > 0 ).astype('int8' )<filter>
def create_transforms(additional):
res = list(additional)
 res.extend([
A.Normalize(
 mean=(0.485, 0.456, 0.406), std=(0.229, 0.224, 0.225)
),
ChannelTranspose()
])
 res = A.Compose(res)
 return res
img_folder = '/kaggle/input/severstal-steel-defect-detection/test_images'
batch_size = 2
num_workers = 0
transforms = [
[],
[A.HorizontalFlip(p=1)]
]
transforms = [create_transforms(t)for t in transforms]
datasets = [TtaWrap(ImageDataset(img_folder=img_folder, transforms=t), tfms=t)for t in transforms]
loaders = [DataLoader(d, num_workers=num_workers, batch_size=batch_size, shuffle=False)for d in datasets]
train_lectures[train_lectures.user_id==5382]<filter>
thresholds = [0.5, 0.5, 0.5, 0.5]
min_area = [600, 600, 1000, 2000]
res = []
total = len(datasets[0])//batch_size
for loaders_batch in tqdm_notebook(zip(*loaders), total=total):
preds = []
image_file = []
for i, batch in enumerate(loaders_batch):
features = batch['features'].cuda()
p = torch.sigmoid(model(features))
p = datasets[i].inverse(p)
 preds.append(p)
 image_file = batch['image_file']
preds = torch.stack(preds)
 preds = torch.mean(preds, dim=0)
 preds = preds.detach().cpu().numpy()
for p, file in zip(preds, image_file):
file = os.path.basename(file)
 for i in range(4):
p_channel = p[i]
imageid_classid = file+'_'+str(i+1)
 p_channel =(p_channel>thresholds[i] ).astype(np.uint8)
 if p_channel.sum() < min_area[i]:
p_channel = np.zeros(p_channel.shape, dtype=p_channel.dtype)
 res.append({
'ImageId_ClassId': imageid_classid,
'EncodedPixels': mask2rle(p_channel)
 })
 df = pd.DataFrame(res)
 df.to_csv('submission.csv', index=False)
user_lecture_stats_part[user_lecture_stats_part.user_id==5382]<drop_column>
df = pd.DataFrame(res)
 df = df.fillna('')
 df.to_csv('submission.csv', index=False )
del(train_lectures )<data_type_conversions>
df['Image'] = df['ImageId_ClassId'].map(lambda x: x.split('_')[0])
 df['Class'] = df['ImageId_ClassId'].map(lambda x: x.split('_')[1])
 df['empty'] = df['EncodedPixels'].map(lambda x: not x)
 df[df['empty'] == False]['Class'].value_counts()
<data_type_conversions><EOS> 
%matplotlib inline
df = pd.read_csv('submission.csv')[:40]
df['Image'] = df['ImageId_ClassId'].map(lambda x: x.split('_')[0])
 df['Class'] = df['ImageId_ClassId'].map(lambda x: x.split('_')[1])
 for row in df.itertuples() :
img_path = os.path.join(img_folder, row.Image)
 img = cv2.imread(img_path)
 mask = rle2mask(row.EncodedPixels,(1600, 256)) \
if isinstance(row.EncodedPixels, str)else np.zeros(( 256, 1600))
if mask.sum() == 0:
continue
fig, axes = plt.subplots(1, 2, figsize=(20, 60))
axes[0].imshow(img/255)
 axes[1].imshow(mask*60)
 axes[0].set_title(row.Image)
 axes[1].set_title(row.Class)
 plt.show()