File size: 5,961 Bytes
022acf4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
import gc
import os
import time
from typing import Tuple

import numpy as np
from tqdm.auto import tqdm

import torch
import torch.nn as nn
import torch.nn.functional as F
import wandb
from newsclassifier.config.config import Cfg, logger
from newsclassifier.data import (NewsDataset, collate, data_split,
                                 load_dataset, preprocess)
from newsclassifier.models import CustomModel
from torch.utils.data import DataLoader

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")


def train_step(train_loader: DataLoader, model, num_classes: int, loss_fn, optimizer, epoch: int) -> float:
    """Train step."""
    model.train()
    loss = 0.0
    total_iterations = len(train_loader)
    desc = f"Training - Epoch {epoch+1}"
    for step, (inputs, labels) in tqdm(enumerate(train_loader), total=total_iterations, desc=desc):
        inputs = collate(inputs)
        for k, v in inputs.items():
            inputs[k] = v.to(device)
        labels = labels.to(device)
        optimizer.zero_grad()  # reset gradients
        y_pred = model(inputs)  # forward pass
        targets = F.one_hot(labels.long(), num_classes=num_classes).float()  # one-hot (for loss_fn)
        J = loss_fn(y_pred, targets)  # define loss
        J.backward()  # backward pass
        optimizer.step()  # update weights
        loss += (J.detach().item() - loss) / (step + 1)  # cumulative loss
    return loss


def eval_step(val_loader: DataLoader, model, num_classes: int, loss_fn, epoch: int) -> Tuple[float, np.ndarray, np.ndarray]:
    """Eval step."""
    model.eval()
    loss = 0.0
    total_iterations = len(val_loader)
    desc = f"Validation - Epoch {epoch+1}"
    y_trues, y_preds = [], []
    with torch.inference_mode():
        for step, (inputs, labels) in tqdm(enumerate(val_loader), total=total_iterations, desc=desc):
            inputs = collate(inputs)
            for k, v in inputs.items():
                inputs[k] = v.to(device)
            labels = labels.to(device)
            y_pred = model(inputs)
            targets = F.one_hot(labels.long(), num_classes=num_classes).float()  # one-hot (for loss_fn)
            J = loss_fn(y_pred, targets).item()
            loss += (J - loss) / (step + 1)
            y_trues.extend(targets.cpu().numpy())
            y_preds.extend(torch.argmax(y_pred, dim=1).cpu().numpy())
    return loss, np.vstack(y_trues), np.vstack(y_preds)


def train_loop(config=None):
    # ====================================================
    # loader
    # ====================================================

    config = dict(
        batch_size=Cfg.batch_size,
        num_classes=Cfg.num_classes,
        epochs=Cfg.epochs,
        dropout_pb=Cfg.dropout_pb,
        learning_rate=Cfg.lr,
        lr_reduce_factor=Cfg.lr_redfactor,
        lr_reduce_patience=Cfg.lr_redpatience,
    )

    with wandb.init(project="NewsClassifier", config=config):
        config = wandb.config

        df = load_dataset(Cfg.dataset_loc)
        ds, headlines_df, class_to_index, index_to_class = preprocess(df)
        train_ds, val_ds = data_split(ds, test_size=Cfg.test_size)

        logger.info("Preparing Data.")

        train_dataset = NewsDataset(train_ds)
        valid_dataset = NewsDataset(val_ds)

        train_loader = DataLoader(train_dataset, batch_size=config.batch_size, shuffle=True, num_workers=4, pin_memory=True, drop_last=True)
        valid_loader = DataLoader(valid_dataset, batch_size=config.batch_size, shuffle=False, num_workers=4, pin_memory=True, drop_last=False)

        # ====================================================
        # model
        # ====================================================

        logger.info("Creating Custom Model.")
        num_classes = config.num_classes
        device = torch.device("cuda" if torch.cuda.is_available() else "cpu")

        model = CustomModel(num_classes=num_classes, dropout_pb=config.dropout_pb)
        model.to(device)

        # ====================================================
        # Training components
        # ====================================================
        criterion = nn.BCEWithLogitsLoss()
        optimizer = torch.optim.Adam(model.parameters(), lr=config.learning_rate)
        scheduler = torch.optim.lr_scheduler.ReduceLROnPlateau(
            optimizer, mode="min", factor=config.lr_reduce_factor, patience=config.lr_reduce_patience
        )

        # ====================================================
        # loop
        # ====================================================
        wandb.watch(model, criterion, log="all", log_freq=10)

        min_loss = np.inf
        logger.info("Staring Training Loop.")
        for epoch in range(config.epochs):
            try:
                start_time = time.time()

                # Step
                train_loss = train_step(train_loader, model, num_classes, criterion, optimizer, epoch)
                val_loss, _, _ = eval_step(valid_loader, model, num_classes, criterion, epoch)
                scheduler.step(val_loss)

                # scoring
                elapsed = time.time() - start_time
                wandb.log({"epoch": epoch + 1, "train_loss": train_loss, "val_loss": val_loss})
                print(f"Epoch {epoch+1} - avg_train_loss: {train_loss:.4f}  avg_val_loss: {val_loss:.4f}  time: {elapsed:.0f}s")

                if min_loss > val_loss:
                    min_loss = val_loss
                    print("Best Score : saving model.")
                    os.makedirs(Cfg.artifacts_path, exist_ok=True)
                    model.save(Cfg.artifacts_path)
                print(f"\nSaved Best Model Score: {min_loss:.4f}\n\n")
            except Exception as e:
                logger.error(f"Epoch - {epoch+1}, {e}")

        wandb.save(os.path.join(Cfg.artifacts_path, "model.pt"))
        torch.cuda.empty_cache()
        gc.collect()


if __name__ == "__main__":
    train_loop()