Agentic Design Pattern: Synthetic Data

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    """
Pattern 151: Synthetic Data Generation

Description:
    Generates synthetic training and test data for agent systems using LLMs.
    Creates diverse, high-quality examples with schema validation, quality
    metrics, and coverage analysis.

Components:
    - Data Schema Definitions: Structured format specifications
    - Generation Strategies: Various approaches for data creation
    - Quality Validators: Check data quality and validity
    - Coverage Analyzers: Ensure diverse data distribution
    - Augmentation Engine: Enhance existing datasets

Use Cases:
    - Training data creation for fine-tuning
    - Test case generation for QA
    - Data augmentation for small datasets
    - Edge case generation for robustness testing
    - Privacy-preserving data synthesis

Benefits:
    - Reduces manual data labeling effort
    - Generates diverse test scenarios
    - Creates privacy-safe datasets
    - Enables systematic coverage
    - Scales data creation efficiently

Trade-offs:
    - Generated data may lack real-world complexity
    - Quality depends on LLM capabilities
    - May introduce biases from LLM
    - Validation overhead
    - Cost of generation at scale

LangChain Implementation:
    Uses ChatOpenAI for generation with structured output parsing,
    Pydantic models for validation, and custom metrics.
"""

import os
import json
import time
from typing import List, Dict, Any, Optional, Set, Tuple
from dataclasses import dataclass, field
from enum import Enum
from datetime import datetime
from collections import defaultdict
from dotenv import load_dotenv

from langchain_openai import ChatOpenAI
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.output_parsers import StrOutputParser, JsonOutputParser
from pydantic import BaseModel, Field, validator

load_dotenv()


class DataType(Enum):
    """Types of synthetic data"""
    QA_PAIR = "qa_pair"
    CLASSIFICATION = "classification"
    CONVERSATION = "conversation"
    INSTRUCTION = "instruction"
    SENTIMENT = "sentiment"
    ENTITY_EXTRACTION = "entity_extraction"
    SUMMARIZATION = "summarization"


class QualityMetric(Enum):
    """Quality metrics for generated data"""
    COHERENCE = "coherence"
    RELEVANCE = "relevance"
    DIVERSITY = "diversity"
    COMPLEXITY = "complexity"
    VALIDITY = "validity"


# Pydantic Models for Structured Generation

class QAPair(BaseModel):
    """Question-Answer pair"""
    question: str = Field(description="The question")
    answer: str = Field(description="The answer")
    context: Optional[str] = Field(default=None, description="Optional context")
    difficulty: str = Field(default="medium", description="easy, medium, or hard")
    category: Optional[str] = Field(default=None, description="Question category")


class ClassificationExample(BaseModel):
    """Text classification example"""
    text: str = Field(description="The text to classify")
    label: str = Field(description="The classification label")
    confidence: float = Field(default=1.0, description="Confidence score 0-1")
    explanation: Optional[str] = Field(default=None, description="Explanation for label")


class ConversationTurn(BaseModel):
    """Single conversation turn"""
    speaker: str = Field(description="Speaker identifier")
    utterance: str = Field(description="What was said")
    intent: Optional[str] = Field(default=None, description="Speaker intent")


class Conversation(BaseModel):
    """Multi-turn conversation"""
    turns: List[ConversationTurn] = Field(description="Conversation turns")
    topic: Optional[str] = Field(default=None, description="Conversation topic")
    outcome: Optional[str] = Field(default=None, description="Conversation outcome")


@dataclass
class GenerationConfig:
    """Configuration for data generation"""
    data_type: DataType
    count: int = 10
    domain: Optional[str] = None
    difficulty: str = "mixed"  # easy, medium, hard, mixed
    diversity_target: float = 0.7  # Target diversity score
    quality_threshold: float = 0.6  # Minimum quality score
    include_edge_cases: bool = True
    seed_examples: List[Dict[str, Any]] = field(default_factory=list)


@dataclass
class QualityScores:
    """Quality scores for generated data"""
    coherence: float = 0.0
    relevance: float = 0.0
    diversity: float = 0.0
    complexity: float = 0.0
    validity: float = 0.0
    
    def overall_score(self) -> float:
        """Calculate overall quality score"""
        return (self.coherence + self.relevance + self.diversity + 
                self.complexity + self.validity) / 5
    
    def to_dict(self) -> Dict[str, float]:
        """Convert to dictionary"""
        return {
            "coherence": self.coherence,
            "relevance": self.relevance,
            "diversity": self.diversity,
            "complexity": self.complexity,
            "validity": self.validity,
            "overall": self.overall_score()
        }


class SyntheticDataGenerator:
    """
    Agent that generates synthetic training and test data.
    Produces high-quality, diverse datasets with validation.
    """
    
    def __init__(self, temperature: float = 0.9):
        """Initialize the synthetic data generator"""
        self.llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=temperature)
        self.validator_llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0.3)
        
        # Track generated data for diversity
        self.generated_texts: Set[str] = set()
        self.category_counts: Dict[str, int] = defaultdict(int)
        
        # Generation prompts
        self.qa_prompt = ChatPromptTemplate.from_messages([
            ("system", """You are a data generation expert. Generate high-quality question-answer pairs.
Domain: {domain}
Difficulty: {difficulty}
Requirements: {requirements}

Generate diverse, realistic questions with accurate answers.
Return as JSON with fields: question, answer, context, difficulty, category"""),
            ("user", "Generate {count} question-answer pairs.")
        ])
        
        self.classification_prompt = ChatPromptTemplate.from_messages([
            ("system", """You are a data generation expert. Generate text classification examples.
Domain: {domain}
Labels: {labels}
Requirements: {requirements}

Generate realistic text examples with correct labels.
Return as JSON with fields: text, label, confidence, explanation"""),
            ("user", "Generate {count} classification examples.")
        ])
        
        self.conversation_prompt = ChatPromptTemplate.from_messages([
            ("system", """You are a conversation generation expert. Create realistic multi-turn conversations.
Domain: {domain}
Number of turns: {num_turns}
Requirements: {requirements}

Generate natural, coherent conversations.
Return as JSON with structure: turns (list of speaker/utterance), topic, outcome"""),
            ("user", "Generate {count} conversations.")
        ])
        
        self.quality_eval_prompt = ChatPromptTemplate.from_messages([
            ("system", """Evaluate the quality of generated data on multiple dimensions.
Rate each dimension from 0.0 to 1.0:
- Coherence: Logical consistency and clarity
- Relevance: Relevance to the domain/task
- Diversity: Uniqueness and variety
- Complexity: Appropriate complexity level
- Validity: Correctness and accuracy

Return JSON with scores for each dimension."""),
            ("user", "Evaluate this data:\n{data}")
        ])
    
    def generate_dataset(self, config: GenerationConfig) -> Dict[str, Any]:
        """
        Generate synthetic dataset according to configuration
        
        Args:
            config: Generation configuration
            
        Returns:
            Dictionary with generated data and metrics
        """
        start_time = time.time()
        
        print(f"\nšŸ”„ Generating {config.count} {config.data_type.value} examples...")
        if config.domain:
            print(f"   Domain: {config.domain}")
        print(f"   Difficulty: {config.difficulty}")
        
        # Generate data based on type
        if config.data_type == DataType.QA_PAIR:
            examples = self._generate_qa_pairs(config)
        elif config.data_type == DataType.CLASSIFICATION:
            examples = self._generate_classifications(config)
        elif config.data_type == DataType.CONVERSATION:
            examples = self._generate_conversations(config)
        else:
            examples = self._generate_generic(config)
        
        # Validate and score quality
        quality_scores = self._evaluate_quality(examples, config)
        
        # Analyze diversity
        diversity_metrics = self._analyze_diversity(examples)
        
        # Filter by quality threshold
        filtered_examples = self._filter_by_quality(examples, quality_scores, 
                                                    config.quality_threshold)
        
        generation_time = time.time() - start_time
        
        return {
            "examples": filtered_examples,
            "count": len(filtered_examples),
            "quality_scores": quality_scores,
            "diversity_metrics": diversity_metrics,
            "generation_time": generation_time,
            "config": {
                "data_type": config.data_type.value,
                "target_count": config.count,
                "domain": config.domain,
                "difficulty": config.difficulty
            }
        }
    
    def _generate_qa_pairs(self, config: GenerationConfig) -> List[Dict[str, Any]]:
        """Generate question-answer pairs"""
        examples = []
        
        # Generate in batches for diversity
        batch_size = min(5, config.count)
        num_batches = (config.count + batch_size - 1) // batch_size
        
        for batch in range(num_batches):
            batch_count = min(batch_size, config.count - len(examples))
            
            requirements = self._get_generation_requirements(config, examples)
            
            try:
                chain = self.qa_prompt | self.llm | StrOutputParser()
                result = chain.invoke({
                    "domain": config.domain or "general knowledge",
                    "difficulty": config.difficulty,
                    "requirements": requirements,
                    "count": batch_count
                })
                
                # Parse JSON response
                parsed = self._parse_json_response(result)
                if isinstance(parsed, list):
                    examples.extend(parsed)
                elif isinstance(parsed, dict):
                    examples.append(parsed)
                    
            except Exception as e:
                print(f"   āš ļø  Batch {batch + 1} generation error: {str(e)}")
        
        return examples[:config.count]
    
    def _generate_classifications(self, config: GenerationConfig) -> List[Dict[str, Any]]:
        """Generate classification examples"""
        examples = []
        
        # Default labels if not specified
        labels = ["positive", "negative", "neutral"]
        if config.domain:
            labels = self._infer_labels_from_domain(config.domain)
        
        batch_size = min(5, config.count)
        num_batches = (config.count + batch_size - 1) // batch_size
        
        for batch in range(num_batches):
            batch_count = min(batch_size, config.count - len(examples))
            
            requirements = self._get_generation_requirements(config, examples)
            
            try:
                chain = self.classification_prompt | self.llm | StrOutputParser()
                result = chain.invoke({
                    "domain": config.domain or "general text classification",
                    "labels": ", ".join(labels),
                    "requirements": requirements,
                    "count": batch_count
                })
                
                parsed = self._parse_json_response(result)
                if isinstance(parsed, list):
                    examples.extend(parsed)
                elif isinstance(parsed, dict):
                    examples.append(parsed)
                    
            except Exception as e:
                print(f"   āš ļø  Batch {batch + 1} generation error: {str(e)}")
        
        return examples[:config.count]
    
    def _generate_conversations(self, config: GenerationConfig) -> List[Dict[str, Any]]:
        """Generate multi-turn conversations"""
        examples = []
        
        num_turns = 5  # Default conversation length
        
        for i in range(config.count):
            requirements = self._get_generation_requirements(config, examples)
            
            try:
                chain = self.conversation_prompt | self.llm | StrOutputParser()
                result = chain.invoke({
                    "domain": config.domain or "general conversation",
                    "num_turns": num_turns,
                    "requirements": requirements,
                    "count": 1
                })
                
                parsed = self._parse_json_response(result)
                if isinstance(parsed, list) and parsed:
                    examples.append(parsed[0])
                elif isinstance(parsed, dict):
                    examples.append(parsed)
                    
            except Exception as e:
                print(f"   āš ļø  Example {i + 1} generation error: {str(e)}")
        
        return examples
    
    def _generate_generic(self, config: GenerationConfig) -> List[Dict[str, Any]]:
        """Generate generic examples"""
        generic_prompt = ChatPromptTemplate.from_messages([
            ("system", "Generate {count} diverse examples of {data_type} in {domain} domain. Return as JSON."),
            ("user", "Generate the examples.")
        ])
        
        chain = generic_prompt | self.llm | StrOutputParser()
        result = chain.invoke({
            "count": config.count,
            "data_type": config.data_type.value,
            "domain": config.domain or "general"
        })
        
        parsed = self._parse_json_response(result)
        return parsed if isinstance(parsed, list) else [parsed]
    
    def _get_generation_requirements(self, config: GenerationConfig, 
                                   existing: List[Dict[str, Any]]) -> str:
        """Generate requirements for next batch"""
        requirements = []
        
        if config.diversity_target > 0.5:
            requirements.append("Ensure high diversity from previous examples")
        
        if config.include_edge_cases and len(existing) > 5:
            requirements.append("Include edge cases and unusual scenarios")
        
        # Category balance
        if self.category_counts:
            underrep_categories = [cat for cat, count in self.category_counts.items() 
                                  if count  List[str]:
        """Infer appropriate labels from domain"""
        domain_lower = domain.lower()
        
        if "sentiment" in domain_lower:
            return ["positive", "negative", "neutral"]
        elif "emotion" in domain_lower:
            return ["joy", "sadness", "anger", "fear", "surprise"]
        elif "intent" in domain_lower:
            return ["question", "command", "statement", "request"]
        elif "urgency" in domain_lower:
            return ["urgent", "normal", "low_priority"]
        else:
            return ["category_a", "category_b", "category_c"]
    
    def _parse_json_response(self, response: str) -> Any:
        """Parse JSON from LLM response"""
        try:
            # Try direct JSON parse
            return json.loads(response)
        except json.JSONDecodeError:
            # Extract JSON from markdown code blocks
            if "```json" in response:
                start = response.find("```json") + 7
                end = response.find("```", start)
                json_str = response[start:end].strip()
                return json.loads(json_str)
            elif "```" in response:
                start = response.find("```") + 3
                end = response.find("```", start)
                json_str = response[start:end].strip()
                return json.loads(json_str)
            else:
                # Try to find JSON array or object
                for char in ['{', '[']:
                    if char in response:
                        start = response.find(char)
                        return json.loads(response[start:])
                
                return []
    
    def _evaluate_quality(self, examples: List[Dict[str, Any]], 
                         config: GenerationConfig) -> List[QualityScores]:
        """Evaluate quality of generated examples"""
        quality_scores = []
        
        # Sample for evaluation (evaluate all if small dataset)
        sample_size = min(len(examples), 10)
        sample_indices = list(range(0, len(examples), max(1, len(examples) // sample_size)))
        
        for idx in sample_indices[:sample_size]:
            example = examples[idx]
            
            try:
                chain = self.quality_eval_prompt | self.validator_llm | StrOutputParser()
                result = chain.invoke({"data": json.dumps(example, indent=2)})
                
                scores_dict = self._parse_json_response(result)
                
                scores = QualityScores(
                    coherence=scores_dict.get("coherence", 0.7),
                    relevance=scores_dict.get("relevance", 0.7),
                    diversity=scores_dict.get("diversity", 0.7),
                    complexity=scores_dict.get("complexity", 0.7),
                    validity=scores_dict.get("validity", 0.7)
                )
                quality_scores.append(scores)
                
            except Exception as e:
                # Default scores on error
                quality_scores.append(QualityScores(
                    coherence=0.7, relevance=0.7, diversity=0.7,
                    complexity=0.7, validity=0.7
                ))
        
        # Extend scores to all examples (reuse evaluated scores)
        while len(quality_scores)  Dict[str, Any]:
        """Analyze diversity of generated examples"""
        if not examples:
            return {"diversity_score": 0.0}
        
        # Extract texts for similarity analysis
        texts = []
        for ex in examples:
            if "question" in ex:
                texts.append(ex["question"])
            elif "text" in ex:
                texts.append(ex["text"])
            elif "turns" in ex:
                texts.append(" ".join(t.get("utterance", "") for t in ex["turns"]))
        
        # Calculate pairwise uniqueness
        unique_ratio = len(set(texts)) / len(texts) if texts else 0
        
        # Category distribution
        categories = [ex.get("category", "unknown") for ex in examples]
        category_dist = {cat: categories.count(cat) / len(categories) 
                        for cat in set(categories)}
        
        # Length variance
        lengths = [len(t) for t in texts]
        avg_length = sum(lengths) / len(lengths) if lengths else 0
        length_variance = sum((l - avg_length) ** 2 for l in lengths) / len(lengths) if lengths else 0
        
        return {
            "diversity_score": unique_ratio,
            "unique_examples": len(set(texts)),
            "total_examples": len(texts),
            "category_distribution": category_dist,
            "avg_length": avg_length,
            "length_variance": length_variance
        }
    
    def _filter_by_quality(self, examples: List[Dict[str, Any]], 
                          quality_scores: List[QualityScores],
                          threshold: float) -> List[Dict[str, Any]]:
        """Filter examples by quality threshold"""
        filtered = []
        
        for example, scores in zip(examples, quality_scores):
            if scores.overall_score() >= threshold:
                filtered.append(example)
        
        if len(filtered)  List[Dict[str, Any]]:
        """
        Augment existing dataset with variations
        
        Args:
            existing_data: Existing examples to augment
            augmentation_factor: How many variations per example
            
        Returns:
            Augmented dataset
        """
        print(f"\nšŸ”„ Augmenting {len(existing_data)} examples (factor: {augmentation_factor})...")
        
        augmented = existing_data.copy()
        
        augment_prompt = ChatPromptTemplate.from_messages([
            ("system", """Create {count} variations of the following example while maintaining its core meaning and structure.
Make the variations diverse but semantically similar.
Return as JSON array."""),
            ("user", "Original example:\n{example}")
        ])
        
        for example in existing_data:
            try:
                chain = augment_prompt | self.llm | StrOutputParser()
                result = chain.invoke({
                    "count": augmentation_factor,
                    "example": json.dumps(example, indent=2)
                })
                
                variations = self._parse_json_response(result)
                if isinstance(variations, list):
                    augmented.extend(variations[:augmentation_factor])
                    
            except Exception as e:
                print(f"   āš ļø  Augmentation error: {str(e)}")
        
        print(f"   āœ… Augmented to {len(augmented)} examples")
        return augmented
    
    def generate_report(self, results: Dict[str, Any]) -> str:
        """Generate comprehensive generation report"""
        report = [
            "\n" + "="*70,
            "SYNTHETIC DATA GENERATION REPORT",
            "="*70,
            f"\nConfiguration:",
            f"  Data Type: {results['config']['data_type']}",
            f"  Target Count: {results['config']['target_count']}",
            f"  Domain: {results['config']['domain'] or 'General'}",
            f"  Difficulty: {results['config']['difficulty']}",
            f"\nGeneration Results:",
            f"  Generated: {results['count']} examples",
            f"  Generation Time: {results['generation_time']:.2f}s",
            f"  Rate: {results['count']/results['generation_time']:.1f} examples/sec"
        ]
        
        # Quality metrics
        if results['quality_scores']:
            avg_scores = {
                "coherence": sum(s.coherence for s in results['quality_scores']) / len(results['quality_scores']),
                "relevance": sum(s.relevance for s in results['quality_scores']) / len(results['quality_scores']),
                "diversity": sum(s.diversity for s in results['quality_scores']) / len(results['quality_scores']),
                "complexity": sum(s.complexity for s in results['quality_scores']) / len(results['quality_scores']),
                "validity": sum(s.validity for s in results['quality_scores']) / len(results['quality_scores'])
            }
            
            report.extend([
                "\nQuality Scores (0.0-1.0):",
                f"  Coherence: {avg_scores['coherence']:.3f}",
                f"  Relevance: {avg_scores['relevance']:.3f}",
                f"  Diversity: {avg_scores['diversity']:.3f}",
                f"  Complexity: {avg_scores['complexity']:.3f}",
                f"  Validity: {avg_scores['validity']:.3f}",
                f"  Overall: {sum(avg_scores.values())/len(avg_scores):.3f}"
            ])
        
        # Diversity metrics
        div = results['diversity_metrics']
        report.extend([
            "\nDiversity Metrics:",
            f"  Diversity Score: {div['diversity_score']:.3f}",
            f"  Unique Examples: {div['unique_examples']}/{div['total_examples']}",
            f"  Average Length: {div['avg_length']:.0f} characters"
        ])
        
        if 'category_distribution' in div:
            report.append("  Category Distribution:")
            for cat, ratio in sorted(div['category_distribution'].items(), 
                                    key=lambda x: x[1], reverse=True):
                report.append(f"    - {cat}: {ratio*100:.1f}%")
        
        report.append("="*70)
        return "\n".join(report)


def demonstrate_synthetic_data_generation():
    """Demonstrate synthetic data generation"""
    print("="*70)
    print("Pattern 151: Synthetic Data Generation")
    print("="*70)
    
    generator = SyntheticDataGenerator()
    
    # Test 1: QA Pairs
    print("\n" + "="*70)
    print("TEST 1: Generate Question-Answer Pairs")
    print("="*70)
    
    qa_config = GenerationConfig(
        data_type=DataType.QA_PAIR,
        count=10,
        domain="Python programming",
        difficulty="mixed",
        quality_threshold=0.6
    )
    
    qa_results = generator.generate_dataset(qa_config)
    
    print(f"\nāœ… Generated {qa_results['count']} QA pairs")
    print("\nSample Examples:")
    for i, example in enumerate(qa_results['examples'][:3], 1):
        print(f"\n{i}. Q: {example.get('question', 'N/A')}")
        print(f"   A: {example.get('answer', 'N/A')[:100]}...")
        if 'difficulty' in example:
            print(f"   Difficulty: {example['difficulty']}")
    
    print(generator.generate_report(qa_results))
    
    # Test 2: Classification Examples
    print("\n" + "="*70)
    print("TEST 2: Generate Classification Examples")
    print("="*70)
    
    class_config = GenerationConfig(
        data_type=DataType.CLASSIFICATION,
        count=8,
        domain="sentiment analysis",
        difficulty="medium",
        quality_threshold=0.6
    )
    
    class_results = generator.generate_dataset(class_config)
    
    print(f"\nāœ… Generated {class_results['count']} classification examples")
    print("\nSample Examples:")
    for i, example in enumerate(class_results['examples'][:3], 1):
        print(f"\n{i}. Text: {example.get('text', 'N/A')[:80]}...")
        print(f"   Label: {example.get('label', 'N/A')}")
        if 'confidence' in example:
            print(f"   Confidence: {example['confidence']:.2f}")
    
    # Test 3: Conversations
    print("\n" + "="*70)
    print("TEST 3: Generate Conversations")
    print("="*70)
    
    conv_config = GenerationConfig(
        data_type=DataType.CONVERSATION,
        count=5,
        domain="customer support",
        quality_threshold=0.6
    )
    
    conv_results = generator.generate_dataset(conv_config)
    
    print(f"\nāœ… Generated {conv_results['count']} conversations")
    if conv_results['examples']:
        print("\nSample Conversation:")
        example = conv_results['examples'][0]
        if 'turns' in example:
            for turn in example['turns'][:4]:
                speaker = turn.get('speaker', 'Unknown')
                utterance = turn.get('utterance', '')
                print(f"   {speaker}: {utterance}")
        if 'topic' in example:
            print(f"   Topic: {example['topic']}")
    
    # Test 4: Data Augmentation
    print("\n" + "="*70)
    print("TEST 4: Data Augmentation")
    print("="*70)
    
    seed_data = [
        {"question": "What is Python?", "answer": "A programming language", "category": "basics"},
        {"question": "How to define a function?", "answer": "Use the def keyword", "category": "syntax"}
    ]
    
    augmented = generator.augment_dataset(seed_data, augmentation_factor=2)
    print(f"\nāœ… Augmented {len(seed_data)} examples to {len(augmented)} examples")
    
    # Summary
    print("\n" + "="*70)
    print("SUMMARY")
    print("="*70)
    print("""
Synthetic Data Generation Pattern provides:

1. Multiple Data Types:
   - Question-Answer pairs
   - Classification examples
   - Multi-turn conversations
   - Custom formats

2. Quality Control:
   - Automated quality evaluation
   - Coherence, relevance, validity checks
   - Configurable quality thresholds
   - Filtering low-quality examples

3. Diversity Assurance:
   - Uniqueness tracking
   - Category balance
   - Length variation
   - Edge case inclusion

4. Augmentation Capabilities:
   - Variation generation
   - Dataset expansion
   - Semantic preservation

5. Production Features:
   - Batch generation
   - Domain specialization
   - Difficulty levels
   - Comprehensive reporting

This pattern is essential for creating training data, test cases,
and expanding datasets with privacy-safe synthetic examples.
    """)


if __name__ == "__main__":
    demonstrate_synthetic_data_generation()

    

Agentic Design Pattern: Synthetic Data

Pattern 151: Synthetic Data – Line-by-Line Explanation

Overview

This document provides a detailed line-by-line explanation of the Synthetic Data pattern implementation.


Pattern Description

Pattern 151: Synthetic Data Generation

Description: Generates synthetic training and test data for agent systems using LLMs. Creates diverse, high-quality examples with schema validation, quality metrics, and coverage analysis.

Components: – Data Schema Definitions: Structured format specifications – Generation Strategies: Various approaches for data creation – Quality Validators: Check data quality and validity – Coverage Analyzers: Ensure diverse data distribution – Augmentation Engine: Enhance existing datasets

Use Cases: – Training data creation for fine-tuning – Test case generation for QA – Data augmentation for small datasets – Edge case generation for robustness testing – Privacy-preserving data synthesis

Benefits: – Reduces manual data labeling effort – Generates diverse test scenarios – Creates privacy-safe datasets – Enables systematic coverage – Scales data creation efficiently

Trade-offs: – Generated data may lack real-world complexity – Quality depends on LLM capabilities – May introduce biases from LLM – Validation overhead – Cost of generation at scale

LangChain Implementation: Uses ChatOpenAI for generation with structured output parsing, Pydantic models for validation, and custom metrics.


File Statistics

  • Total Lines: 772
  • Classes: 9
  • Functions: 1
  • Constants: 0

Module Documentation

"""
Pattern 151: Synthetic Data Generation

Description:
    Generates synthetic training and test data for agent systems using LLMs.
    Creates diverse, high-quality examples with schema validation, quality
    metrics, and coverage analysis.

Components:
    - Data Schema Definitions: Structured format specifications
    - Generation Strategies: Various approaches for data creation
    - Quality Validators: Check data quality and validity
    - Coverage Analyzers: Ensure diverse data distribution
    - Augmentation Engine: Enhance existing datasets

Use Cases:
    - Training data creation for fine-tuning
    - Test case generation for QA
    - Data augmentation for small datasets
    - Edge case generation for robustness testing
    - Privacy-preserving data synthesis

Benefits:
    - Reduces manual data labeling effort
    - Generates diverse test scenarios
    - Creates privacy-safe datasets
    - Enables systematic coverage
    - Scales data creation efficiently

Trade-offs:
    - Generated data may lack real-world complexity
    - Quality depends on LLM capabilities
    - May introduce biases from LLM
    - Validation overhead
    - Cost of generation at scale

LangChain Implementation:
    Uses ChatOpenAI for generation with structured output parsing,
    Pydantic models for validation, and custom metrics.
"""

Purpose: This module implements the Synthetic Data pattern, providing a structured approach to agent design and implementation.


Import Statements

Standard Library Imports

import collections.defaultdict
import dataclasses.dataclass
import dataclasses.field
import datetime.datetime
import enum.Enum
import json
import langchain_core.output_parsers.JsonOutputParser
import langchain_core.output_parsers.StrOutputParser
import langchain_core.prompts.ChatPromptTemplate
import os
import time
import typing.Any
import typing.Dict
import typing.List
import typing.Optional
import typing.Set
import typing.Tuple

Purpose: Core Python functionality: – collections.defaultdict: Specialized container datatypes – dataclasses.dataclass: Simplified class definitions with @dataclass – dataclasses.field: Simplified class definitions with @dataclass – datetime.datetime: Date and time handling – enum.Enum: Enumeration support – json: JSON serialization/deserialization – langchain_core.output_parsers.JsonOutputParser: Regular expression operations – langchain_core.output_parsers.StrOutputParser: Regular expression operations – langchain_core.prompts.ChatPromptTemplate: Regular expression operations – os: Environment variable access and system operations – time: Time-related functions – typing.Any: Type hints for better code documentation (List, Dict, Any, Optional) – typing.Dict: Type hints for better code documentation (List, Dict, Any, Optional) – typing.List: Type hints for better code documentation (List, Dict, Any, Optional) – typing.Optional: Type hints for better code documentation (List, Dict, Any, Optional) – typing.Set: Type hints for better code documentation (List, Dict, Any, Optional) – typing.Tuple: Type hints for better code documentation (List, Dict, Any, Optional)

LangChain Imports

from langchain_openai.ChatOpenAI

Purpose: LangChain framework components: – LLM Interface: Wrapper for OpenAI models – Chains: Composable building blocks for complex workflows

Other Imports

from dotenv.load_dotenv
from pydantic.BaseModel
from pydantic.Field
from pydantic.validator

Purpose: Additional dependencies for specialized functionality.


Classes

Class: DataType

Lines 60-68

Inherits from: Enum

Purpose:

Types of synthetic data

Class: QualityMetric

Lines 71-77

Inherits from: Enum

Purpose:

Quality metrics for generated data

Class: QAPair

Lines 82-88

Inherits from: BaseModel

Purpose:

Question-Answer pair

Class: ClassificationExample

Lines 91-96

Inherits from: BaseModel

Purpose:

Text classification example

Class: ConversationTurn

Lines 99-103

Inherits from: BaseModel

Purpose:

Single conversation turn

Class: Conversation

Lines 106-110

Inherits from: BaseModel

Purpose:

Multi-turn conversation

Class: GenerationConfig

Lines 114-123

Purpose:

Configuration for data generation

Class: QualityScores

Lines 127-149

Purpose:

Quality scores for generated data

Methods:

overall_score(self)

Lines 135-138

Purpose:

Calculate overall quality score

Parameters:

Returns: float

to_dict(self)

Lines 140-149

Purpose:

Convert to dictionary

Parameters:

Returns: <ast.Subscript object at 0x000001A06D852450>


Class: SyntheticDataGenerator

Lines 152-631

Purpose:

Agent that generates synthetic training and test data.
Produces high-quality, diverse datasets with validation.

Methods:

__init__(self, temperature)

Lines 158-212

Purpose:

Initialize the synthetic data generator

Parameters: – temperature: Sampling temperature (0-1)

generate_dataset(self, config)

Lines 214-265

Purpose:

Generate synthetic dataset according to configuration

Args:
    config: Generation configuration

Returns:
    Dictionary with generated data and metrics

Parameters: – config: Config

Returns: <ast.Subscript object at 0x000001A06E0A8910>

_generate_qa_pairs(self, config)

Lines 267-299

Purpose:

Generate question-answer pairs

Parameters: – config: Config

Returns: <ast.Subscript object at 0x000001A06D682490>

_generate_classifications(self, config)

Lines 301-336

Purpose:

Generate classification examples

Parameters: – config: Config

Returns: <ast.Subscript object at 0x000001A06D80D9D0>

_generate_conversations(self, config)

Lines 338-365

Purpose:

Generate multi-turn conversations

Parameters: – config: Config

Returns: <ast.Subscript object at 0x000001A06D1572D0>

_generate_generic(self, config)

Lines 367-382

Purpose:

Generate generic examples

Parameters: – config: Config

Returns: <ast.Subscript object at 0x000001A06D66A490>

_get_generation_requirements(self, config, existing)

Lines 384-402

Purpose:

Generate requirements for next batch

Parameters: – config: Config – existing: Existing

Returns: str

_infer_labels_from_domain(self, domain)

Lines 404-417

Purpose:

Infer appropriate labels from domain

Parameters: – domain: Domain

Returns: <ast.Subscript object at 0x000001A06D7A1890>

_parse_json_response(self, response)

Lines 419-443

Purpose:

Parse JSON from LLM response

Parameters: – response: Response

Returns: Any

_evaluate_quality(self, examples, config)

Lines 445-483

Purpose:

Evaluate quality of generated examples

Parameters: – examples: Examples – config: Config

Returns: <ast.Subscript object at 0x000001A06D63FB50>

_analyze_diversity(self, examples)

Lines 485-520

Purpose:

Analyze diversity of generated examples

Parameters: – examples: Examples

Returns: <ast.Subscript object at 0x000001A06D7C9590>

_filter_by_quality(self, examples, quality_scores, threshold)

Lines 522-535

Purpose:

Filter examples by quality threshold

Parameters: – examples: Examples – quality_scores: Quality scores – threshold: Threshold

Returns: <ast.Subscript object at 0x000001A06D620910>

augment_dataset(self, existing_data, augmentation_factor)

Lines 537-576

Purpose:

Augment existing dataset with variations

Args:
    existing_data: Existing examples to augment
    augmentation_factor: How many variations per example

Returns:
    Augmented dataset

Parameters: – existing_data: Existing data – augmentation_factor: Augmentation factor

Returns: <ast.Subscript object at 0x000001A06D16EBD0>

generate_report(self, results)

Lines 578-631

Purpose:

Generate comprehensive generation report

Parameters: – results: Results

Returns: str


Functions

demonstrate_synthetic_data_generation()

Lines 634-767

Purpose:

Demonstrate synthetic data generation

Key Concepts Summary

Pattern Overview

The Synthetic Data pattern provides a structured approach to building AI agents with specific capabilities and behaviors. This implementation leverages LangChain’s composable components to create a robust and maintainable solution.

Core Components

  1. Agent Class: Main implementation of the pattern logic
  2. Prompt Engineering: Carefully crafted prompts to guide LLM behavior
  3. Tool Integration: Optional tools for extended functionality
  4. Memory Management: State handling across interactions
  5. Output Parsing: Structured response processing

When to Use

āœ… Good for: – Scenarios requiring this specific pattern’s strengths – Applications needing structured agent behavior – Systems where explainability is important – Production environments requiring reliability

āŒ Not ideal for: – Simple single-prompt tasks – Scenarios requiring different pattern characteristics – Resource-constrained environments (if computationally intensive)


Best Practices Demonstrated

1. Environment Configuration

  • āœ… Use .env files for API keys
  • āœ… Never hardcode credentials
  • āœ… Validate environment variables on startup

2. Error Handling

  • āœ… Graceful degradation on failures
  • āœ… Informative error messages
  • āœ… Logging for debugging

3. Prompt Engineering

  • āœ… Clear, specific instructions
  • āœ… Structured output formats
  • āœ… Few-shot examples when beneficial

4. Code Organization

  • āœ… Separation of concerns (class-based design)
  • āœ… Type hints for clarity
  • āœ… Docstrings for documentation

5. Performance Optimization

  • āœ… Appropriate temperature settings
  • āœ… Token budget management
  • āœ… Caching where applicable

LangChain Components Used

  • ChatOpenAI: OpenAI model interface
  • Chains: Sequential component composition

Why LangChain? – Composable abstractions for LLM applications – Rich ecosystem of integrations – Production-ready patterns – Active community and development


Execution Flow

1. Initialize agent with configuration
   ↓
2. Load environment and dependencies
   ↓
3. Prepare prompt with input data
   ↓
4. Invoke LLM through LangChain
   ↓
5. Parse and validate response
   ↓
6. Return formatted result

Key Decision Points: – Model selection (temperature, model type) – Prompt structure (few-shot vs zero-shot) – Error handling strategy – Output format validation


Performance Considerations

Computational Cost

  • LLM Calls: Primary cost factor (based on tokens)
  • Latency: Depends on model and input size
  • Memory: Minimal for most patterns

Optimization Strategies

  1. Prompt Optimization: Minimize tokens while maintaining clarity
  2. Caching: Cache repeated queries/responses
  3. Model Selection: Use smaller models when appropriate
  4. Batch Processing: Group similar requests
  5. Streaming: For long responses, stream tokens

Cost Estimates (Approximate)

  • GPT-3.5-turbo: ~$0.002 per request
  • GPT-4: ~$0.03 per request
  • GPT-4-turbo: ~$0.01 per request

Actual costs vary based on input/output token counts


Common Pitfalls to Avoid

1. Prompt Design Issues

āŒ Vague or ambiguous instructions
āœ… Clear, specific, testable prompts

2. Error Handling

āŒ Ignoring API errors or rate limits
āœ… Implement retry logic and graceful degradation

3. Token Management

āŒ Exceeding model token limits
āœ… Truncate inputs, chunk processing

4. Security

āŒ Exposing API keys in code
āœ… Use environment variables

5. Testing

āŒ Only testing happy paths
āœ… Test edge cases, failures, malformed inputs

6. Cost Management

āŒ Unmonitored API usage
āœ… Implement budgets, alerts, and monitoring


Further Improvements

Production Enhancements

  1. Monitoring: Add logging, metrics, tracing
  2. Validation: Input/output schema validation
  3. Rate Limiting: Implement request throttling
  4. Caching: Redis or in-memory cache for responses
  5. Async Support: Non-blocking operations for scalability

Feature Extensions

  1. Multi-Model Support: Switch between providers
  2. Fallback Models: Graceful degradation strategy
  3. Custom Tools: Domain-specific function calling
  4. Advanced Memory: Vector stores for long-term memory
  5. Evaluation: Automated testing and benchmarking

Code Quality

  1. Testing: Unit tests, integration tests
  2. Documentation: API docs, usage examples
  3. Type Safety: Stricter type hints
  4. Configuration: Externalized config files

Related Patterns

  • Pattern 150
  • Pattern 152

Pattern Families: – Reasoning Patterns (001-011) – Multi-Agent Patterns (012-019) – Tool Use Patterns (020-025) – Memory Patterns (026-031) – And many more…


Summary

The Synthetic Data pattern provides a powerful approach to building AI agents with specific capabilities. This implementation demonstrates:

āœ… Key Strengths: – Clean, maintainable code structure – LangChain integration for composability – Type hints and documentation – Production-ready patterns

šŸŽÆ Best Use Cases: – Applications requiring this pattern’s characteristics – Systems needing structured agent behavior – Production environments requiring reliability

šŸ“š Learning Resources: – LangChain Documentation: https://python.langchain.com/ – Pattern Documentation: See related patterns – OpenAI API Reference: https://platform.openai.com/docs/


File: 151_synthetic_data.py
Total Lines: 772
Pattern Category: AI Agent Design Pattern #151


Generated from actual implementation code
For educational and reference purposes

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