111 lines
2.5 KiB
Markdown
111 lines
2.5 KiB
Markdown
---
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layout: default
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title: "Structured Output"
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parent: "Paradigm"
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nav_order: 1
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---
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# Structured Output
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In many use cases, you may want the LLM to output a specific structure, such as a list or a dictionary with predefined keys.
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There are several approaches to achieve a structured output:
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- **Prompting** the LLM to strictly return a defined structure.
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- Using LLMs that natively support **schema enforcement**.
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- **Post-processing** the LLM’s response to extract structured content.
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In practice, **Prompting** is simple and reliable for modern LLMs.
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### Example Use Cases
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- Extracting Key Information
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```yaml
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product:
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name: Widget Pro
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price: 199.99
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description: |
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A high-quality widget designed for professionals.
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Recommended for advanced users.
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```
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- Summarizing Documents into Bullet Points
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```yaml
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summary:
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- This product is easy to use.
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- It is cost-effective.
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- Suitable for all skill levels.
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```
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- Generating Configuration Files
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```yaml
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server:
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host: 127.0.0.1
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port: 8080
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ssl: true
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```
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## Prompt Engineering
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When prompting the LLM to produce **structured** output:
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1. **Wrap** the structure in code fences (e.g., ` ```yaml`).
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2. **Validate** that all required fields exist (and let `Node` handles retry).
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### Example Text Summarization
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```python
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class SummarizeNode(Node):
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def exec(self, prep_res):
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# Suppose `prep_res` is the text to summarize.
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prompt = f"""
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Please summarize the following text as YAML, with exactly 3 bullet points
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{prep_res}
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Now, output:
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```yaml
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summary:
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- bullet 1
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- bullet 2
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- bullet 3
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```"""
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response = call_llm(prompt)
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yaml_str = response.split("```yaml")[1].split("```")[0].strip()
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import yaml
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structured_result = yaml.safe_load(yaml_str)
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assert "summary" in structured_result
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assert isinstance(structured_result["summary"], list)
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return structured_result
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```
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### Why YAML instead of JSON?
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Current LLMs struggle with escaping. YAML is easier with strings since they don’t always need quotes.
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**In JSON**
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```json
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{
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"dialogue": "Alice said: \"Hello Bob.\\nHow are you?\\nI am good.\""
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}
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```
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- Every double quote inside the string must be escaped with `\"`.
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- Each newline in the dialogue must be represented as `\n`.
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**In YAML**
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```yaml
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dialogue: |
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Alice said: "Hello Bob.
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How are you?
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I am good."
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```
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- No need to escape interior quotes—just place the entire text under a block literal (`|`).
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- Newlines are naturally preserved without needing `\n`. |