# Ds Data Profiling

> Provides Extracts data profiles, schemas, metadata, and statistical summaries to understand data structure, quality, and characteristics at scale

- Skill: `paulpas/ds-data-profiling` (Agent Skill)
- Install (CLI): `npx skillmds@latest add paulpas/ds-data-profiling`
- Raw SKILL.md: https://api.skillmd.com/api/skills/paulpas/ds-data-profiling/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: paulpas (https://skillmd.com/u/paulpas)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/paulpas/ds-data-profiling

---





# Data Profiling

Comprehensive guide to data profiling in machine learning and data science workflows.

## When to Use This Skill

- Solving real-world exploratory data analysis problems
- Building machine learning pipelines with data profiling
- Implementing best practices for data profiling
- Optimizing model performance using data profiling techniques
- Learning industry-standard approaches to data profiling

## When NOT to Use This Skill

- When using pre-built libraries without understanding underlying concepts
- For toy problems that don't require data profiling rigor
- When domain expertise in specific problem requires different approach
- If your problem doesn't require the complexity this skill provides

## Purpose and Key Concepts

Data Profiling is a critical component of the machine learning workflow. This skill covers:

1. **Theoretical foundations** — Mathematical principles and statistical concepts
2. **Practical implementation** — Working code examples and patterns
3. **Common pitfalls** — Mistakes to avoid and how to recover from them
4. **Best practices** — Industry-standard approaches and optimization techniques

## Core Workflow

1. **Understand the problem** — Clearly define what you're solving for
2. **Select approach** — Choose the right technique for your data and constraints
3. **Implement solution** — Write clean, tested code following best practices
4. **Validate results** — Verify your implementation with tests and validation
5. **Optimize performance** — Improve efficiency and accuracy incrementally

## Implementation Patterns

### Pattern 1: Basic Data Profiling

```python
import pandas as pd
import numpy as np

def basic_data_profiling(df: pd.DataFrame) -> dict:
    """Generate a basic statistical and structural profile of a DataFrame."""
    if df.empty:
        raise ValueError("DataFrame cannot be empty")
    
    profile = {
        'shape': df.shape
        'columns': list(df.columns)
        'dtypes': df.dtypes.to_dict()
        'missing_values': df.isnull().sum().to_dict()
        'missing_percentages': (df.isnull().mean() * 100).round(2).to_dict()
        'numeric_summary': df.describe().to_dict() if len(df.select_dtypes(include='number').columns) > 0 else {}
        'categorical_summary': {col: df[col].nunique() for col in df.select_dtypes(include='object').columns}
    }
    return profile

# Example usage
if __name__ == "__main__":
    sample_df = pd.DataFrame({
        'age': [25, 30, 35, 40, np.nan]
        'salary': [50000, 60000, 75000, 80000, 90000]
        'department': ['HR', 'IT', 'IT', 'HR', 'Finance']
    })
    results = basic_data_profiling(sample_df)
    print("Profile generated successfully")
    print(f"Missing values: {results['missing_values']}")
```

### Pattern 2: Production-Ready Data Profiling

```python
import logging
import pandas as pd
import numpy as np
from typing import Any, Dict, List

logger = logging.getLogger(__name__)

class DataProfiling:
    """Production implementation of Data Profiling"""
    
    def __init__(self, include_correlations: bool = True, sample_size: int = 10000):
        self.include_correlations = include_correlations
        self.sample_size = sample_size
        logger.info("DataProfiling initialized")
    
    def execute(self, data: pd.DataFrame) -> Dict[str, Any]:
        """Execute Data Profiling on data"""
        if data is None or data.empty:
            raise ValueError("Input data cannot be None or empty")
        
        logger.info(f"Starting profiling on {data.shape[0]} rows and {data.shape[1]} columns")
        
        profile = {
            'metadata': {
                'rows': len(data)
                'columns': len(data.columns)
                'memory_usage_mb': round(data.memory_usage(deep=True).sum() / 1024**2, 2)
            }
            'data_types': data.dtypes.to_dict()
            'null_counts': data.isnull().sum().to_dict()
            'null_percentages': (data.isnull().mean() * 100).round(2).to_dict()
            'unique_counts': data.nunique().to_dict()
        }
        
        numeric_cols = data.select_dtypes(include=[np.number]).columns
        if len(numeric_cols) > 0:
            profile['descriptive_stats'] = data[numeric_cols].describe().to_dict()
            if self.include_correlations:
                profile['correlation_matrix'] = data[numeric_cols].corr().round(3).to_dict()
        
        logger.info("Profiling completed successfully")
        return profile
```

## Best Practices

- ✅ Always validate your implementation on test data
- ✅ Document your assumptions and methodology
- ✅ Use version control for reproducibility
- ✅ Monitor performance metrics in production
- ✅ Periodically review and update your approach
- ✅ Test with edge cases and outliers
- ✅ Log all significant operations for debugging

## Common Pitfalls

| Pitfall | Problem | Solution |
|

---

---

## Constraints

### MUST DO
- Validate all data preprocessing steps are fit-only on training data, never on validation or test sets
- Implement reproducible pipelines with fixed random seeds and deterministic operations where possible
- Report model performance with confidence intervals via bootstrapping or cross-validation across multiple runs
- Log all experiments with parameters, metrics, and artifacts using MLflow or equivalent tracking system

### MUST NOT DO
- Do not evaluate a model on the same data used for training — always hold out a proper test set
- Avoid overfitting to the validation set by limiting hyperparameter search iterations
- Never use features that can only be computed at inference time (look-ahead bias)
- Do not report single-run accuracy without statistical significance testing or error bars


## Live References

> Authoritative documentation links for this skill's domain. The model follows markdown links at load time to resolve external references and inline content.

- [Data Profiling — Wikipedia](https://en.wikipedia.org/wiki/Data_profiling)
- [dbt Data Quality Guide](https://docs.getdbt.com/docs/collaborate/guides/data-quality)
- [Great Expectations Documentation](https://docs.greatexpectations.io/)
- [ydata-profiling Library Docs](https://docs.profiling.ydata.ai/latest/)
- [Data Quality Best Practices (Gartner)](https://www.gartner.com/en/articles/data-quality-best-practices)