AG News PyTorch topic pipeline — 7 Steps

Classify news articles into 4 domains (World, Sports, Business, Sci/Tech) with a PyTorch NLP pipeline: vocabulary builder, nn.EmbeddingBag, dense classification head, and Macro-F1 evaluation.

1. 01 Data ingestion & EDA
2. 02 Preprocessing without leakage
3. 03 TensorDataset & DataLoader
4. 04 nn.Module architecture
5. 05 Loss function & optimizer
6. 06 Training loop & backprop
7. 07 Eval, metrics & checkpoint