README.md

---
viewer: false
tags: [uv-script, classification, vllm, structured-outputs, gpu-required]
---

# Dataset Classification with vLLM

Efficient text classification for Hugging Face datasets using vLLM with structured outputs. This script provides GPU-accelerated classification with guaranteed valid outputs through guided decoding.

## 🚀 Quick Start

```bash
# Classify IMDB reviews
uv run classify-dataset.py \
  --input-dataset stanfordnlp/imdb \
  --column text \
  --labels "positive,negative" \
  --output-dataset user/imdb-classified
```

That's it! No installation, no setup - just `uv run`.

## 📋 Requirements

- **GPU Required**: This script uses vLLM for efficient inference
- Python 3.10+
- UV (will handle all dependencies automatically)
- vLLM >= 0.6.6 (for guided decoding support)

## 🎯 Features

- **Guaranteed valid outputs** using vLLM's guided decoding with outlines
- **Zero-shot classification** with structured generation
- **GPU-optimized** with vLLM's automatic batching for maximum efficiency
- **Robust text handling** with preprocessing and validation
- **Three prompt styles** for different use cases
- **Automatic progress tracking** and detailed statistics
- **Direct Hub integration** - read and write datasets seamlessly

## 💻 Usage

### Basic Classification

```bash
uv run classify-dataset.py \
  --input-dataset <dataset-id> \
  --column <text-column> \
  --labels <comma-separated-labels> \
  --output-dataset <output-id>
```

### Arguments

**Required:**
- `--input-dataset`: Hugging Face dataset ID (e.g., `stanfordnlp/imdb`, `user/my-dataset`)
- `--column`: Name of the text column to classify
- `--labels`: Comma-separated classification labels (e.g., `"spam,ham"`)
- `--output-dataset`: Where to save the classified dataset

**Optional:**
- `--model`: Model to use (default: `HuggingFaceTB/SmolLM3-3B`)
- `--prompt-style`: Choose from `simple`, `detailed`, or `reasoning` (default: `simple`)
- `--split`: Dataset split to process (default: `train`)
- `--max-samples`: Limit samples for testing
- `--temperature`: Generation temperature (default: 0.1)
- `--guided-backend`: Backend for guided decoding (default: `outlines`)
- `--hf-token`: Hugging Face token (or use `HF_TOKEN` env var)

### Prompt Styles

- **simple**: Direct classification prompt
- **detailed**: Emphasizes exact category matching
- **reasoning**: Includes brief analysis before classification

All styles benefit from structured output guarantees - the model can only output valid labels!

## 📊 Examples

### Sentiment Analysis
```bash
uv run classify-dataset.py \
  --input-dataset stanfordnlp/imdb \
  --column text \
  --labels "positive,negative" \
  --output-dataset user/imdb-sentiment
```

### Support Ticket Classification
```bash
uv run classify-dataset.py \
  --input-dataset user/support-tickets \
  --column content \
  --labels "bug,feature_request,question,other" \
  --output-dataset user/tickets-classified \
  --prompt-style reasoning
```

### News Categorization
```bash
uv run classify-dataset.py \
  --input-dataset ag_news \
  --column text \
  --labels "world,sports,business,tech" \
  --output-dataset user/ag-news-categorized \
  --model meta-llama/Llama-3.2-3B-Instruct
```

## 🚀 Running on HF Jobs

This script is optimized for [Hugging Face Jobs](https://huggingface.co/docs/hub/spaces-gpu-jobs) (requires Pro subscription or Team/Enterprise organization):

```bash
# Run on L4 GPU with vLLM image
hf jobs uv run \
  --flavor l4x1 \
  --image vllm/vllm-openai:latest \
  classify-dataset.py \
  --input-dataset stanfordnlp/imdb \
  --column text \
  --labels "positive,negative" \
  --output-dataset user/imdb-classified

# Run on A10 GPU with custom model
hf jobs uv run \
  --flavor a10g-large \
  --image vllm/vllm-openai:latest \
  classify-dataset.py \
  --input-dataset user/reviews \
  --column review_text \
  --labels "1,2,3,4,5" \
  --output-dataset user/reviews-rated \
  --model mistralai/Mistral-7B-Instruct-v0.3 \
  --prompt-style detailed
```

### GPU Flavors
- `t4-small`: Budget option for smaller models
- `l4x1`: Good balance for 7B models
- `a10g-small`: Fast inference for 3B models
- `a10g-large`: More memory for larger models
- `a100-large`: Maximum performance

## 🔧 Advanced Usage

### Using Different Models

The default model is SmolLM3-3B, but you can use any instruction-tuned model:

```bash
# Larger model for complex classification
uv run classify-dataset.py \
  --input-dataset user/legal-docs \
  --column text \
  --labels "contract,patent,brief,memo,other" \
  --output-dataset user/legal-classified \
  --model Qwen/Qwen2.5-7B-Instruct
```

### Large Datasets

vLLM automatically handles batching for optimal performance. For very large datasets, it will process efficiently without manual intervention:

```bash
uv run classify-dataset.py \
  --input-dataset user/huge-dataset \
  --column text \
  --labels "A,B,C" \
  --output-dataset user/huge-classified
```

## 📈 Performance

- **SmolLM3-3B**: ~50-100 texts/second on A10
- **7B models**: ~20-50 texts/second on A10
- vLLM automatically optimizes batching for best throughput

## 🤝 How It Works

1. **vLLM**: Provides efficient GPU batch inference
2. **Guided Decoding**: Uses outlines to guarantee valid label outputs
3. **Structured Generation**: Constrains model outputs to exact label choices
4. **UV**: Handles all dependencies automatically

The script loads your dataset, preprocesses texts, classifies each one using guided decoding to ensure only valid labels are generated, then saves the results as a new column in the output dataset.

## 🐛 Troubleshooting

### CUDA Not Available
This script requires a GPU. Run it on:
- A machine with NVIDIA GPU
- HF Jobs (recommended)
- Cloud GPU instances

### Out of Memory
- Use a smaller model
- Use a larger GPU (e.g., a100-large)

### Invalid/Skipped Texts
- Texts shorter than 3 characters are skipped
- Empty or None values are marked as invalid
- Very long texts are truncated to 4000 characters

### Classification Quality
- With guided decoding, outputs are guaranteed to be valid labels
- For better results, use clear and distinct label names
- Try the `reasoning` prompt style for complex classifications
- Use a larger model for nuanced tasks

### vLLM Version Issues
If you see `ImportError: cannot import name 'GuidedDecodingParams'`:
- Your vLLM version is too old (requires >= 0.6.6)
- The script specifies the correct version in its dependencies
- UV should automatically install the correct version

## 📝 License

This script is provided as-is for use with the UV Scripts organization.