doubletake 1.0.0b1

doubletake is a module to scrub PII from datasets

doubletake

Intelligent PII Detection and Replacement for Python

doubletake is a powerful, flexible library for automatically detecting and replacing Personally Identifiable Information (PII) in your data structures. Whether you're anonymizing datasets for testing, protecting sensitive information in logs, or ensuring GDPR compliance, doubletake makes it effortless.

✨ Key Features

• 🚀 High Performance: Choose between fast JSON-based processing or flexible tree traversal
• 🎯 Smart Detection: Built-in patterns for emails, phones, SSNs, credit cards, IPs, and URLs
• 🔧 Highly Configurable: Custom patterns, callbacks, and replacement strategies
• 📊 Realistic Fake Data: Generate believable replacements using the Faker library
• 🌳 Deep Traversal: Handle complex nested data structures automatically
• ⚡ Zero Dependencies: Lightweight with minimal external requirements
• 🛡️ Type Safe: Full TypeScript-style type hints for better development experience
• 📋 Path Targeting: Precisely target specific data paths for replacement

🎯 Why doubletake?

The Problem: You have sensitive data in complex structures that needs to be anonymized for testing, logging, or compliance, but existing solutions are either too rigid, too slow, or don't handle your specific use cases.

The Solution: doubletake provides intelligent PII detection with multiple processing strategies, letting you choose the perfect balance of performance and flexibility for your needs.

🚀 Quick Start

Installation

pip install doubletake
# or
pipenv install doubletake
# or
poetry add doubletake

Basic Usage

from doubletake import DoubleTake

# Initialize with default settings
db = DoubleTake()

# Your data with PII
data = [
    {
        "user_id": 12345,
        "name": "John Doe",
        "email": "[e-mail]",
        "phone": "555-123-4567",
        "ssn": "123-45-6789"
    },
    {
        "customer": {
            "contact": "[e-mail]",
            "billing": {
                "card": "4532-1234-5678-9012",
                "address": "123 Main St"
            }
        }
    }
]

# Replace PII automatically
masked_data = db.mask_data(data)

print(masked_data)
# Output:
# [
#   {
#     "user_id": 12345,
#     "name": "John Doe", 
#     "email": "****@******.***",
#     "phone": "***-***-****",
#     "ssn": "***-**-****"
#   },
#   ...
# ]

🔧 Advanced Configuration

Using Realistic Fake Data

from doubletake import DoubleTake

# Generate realistic fake data instead of asterisks
db = DoubleTake(use_faker=True)

masked_data = db.mask_data(data)
# Emails become: [e-mail]
# Phones become: [phone]  
# SSNs become: 987-65-4321

Custom Replacement Logic

def custom_replacer(item, key, pattern_type, breadcrumbs):
    """Custom replacement with full context"""
    if pattern_type == 'email':
        return "***REDACTED_EMAIL***"
    elif pattern_type == 'ssn':
        return "XXX-XX-XXXX"
    else:
        return "***CLASSIFIED***"

db = DoubleTake(callback=custom_replacer)

Targeting Specific Patterns

# Only replace certain types, allow others through
db = DoubleTake(
    allowed=['email'],  # Don't replace emails
    extras=[r'CUST-\d+', r'REF-[A-Z]{3}-\d{4}']  # Custom patterns
)

Precise Path Targeting

# Only replace PII at specific data paths
db = DoubleTake(
    known_paths=[
        'customer.email',
        'billing.ssn', 
        'contacts.emergency.phone'
    ]
)

🏗️ Architecture

doubletake offers two complementary processing strategies:

🚀 JSONGrepper (High Performance)

• Best for: Large datasets, simple replacement needs
• Speed: ⚡ Fastest option
• Method: JSON serialization + regex replacement
• Trade-offs: Less flexibility, no custom callbacks

# Automatically chosen when no custom logic needed
db = DoubleTake()  # Uses JSONGrepper internally

🌳 DictWalker (Maximum Flexibility)

• Best for: Complex logic, custom callbacks, path targeting
• Speed: 🐢 Slower but more capable
• Method: Recursive tree traversal
• Features: Full context, breadcrumbs, custom callbacks

# Automatically chosen when using advanced features
db = DoubleTake(use_faker=True)  # Uses DictWalker
db = DoubleTake(callback=my_func)  # Uses DictWalker

📊 Built-in PII Patterns

Pattern	Description	Example
email	Email addresses	[e-mail]
phone	Phone numbers (US formats)	555-123-4567, [phone]
ssn	Social Security Numbers	123-45-6789, 123456789
credit_card	Credit card numbers	4532-1234-5678-9012
ip_address	IPv4 addresses	192.168.1.1
url	HTTP/HTTPS URLs	https://example.com/path

🎛️ Configuration Options

db = DoubleTake(
    use_faker=False,           # Use fake data vs asterisks
    callback=None,             # Custom replacement function
    allowed=[],                # Pattern types to skip
    extras=[],                 # Additional regex patterns  
    known_paths=[],            # Specific paths to target
    replace_with='*',          # Character for replacements
    maintain_length=False      # Preserve original string length
)

🧪 Real-World Examples

API Response Sanitization

# Sanitize API responses for logging
api_response = {
    "status": "success",
    "data": {
        "users": [
            {"id": 1, "email": "[e-mail]", "role": "admin"},
            {"id": 2, "email": "[e-mail]", "role": "user"}
        ]
    },
    "metadata": {"request_ip": "203.0.113.42"}
}

db = DoubleTake()
safe_response = db.mask_data([api_response])[0]
# Safe to log without exposing PII

Database Export Anonymization

# Anonymize database exports for development
db_records = [
    {"patient_id": "PT001", "ssn": "123-45-6789", "email": "[e-mail]"},
    {"patient_id": "PT002", "ssn": "987-65-4321", "email": "[e-mail]"}
]

db = DoubleTake(
    use_faker=True,
    allowed=[],  # Replace all PII types
)

anonymized_records = db.mask_data(db_records)
# Safe for development environments

Configuration File Sanitization

# Remove secrets from config files
config = {
    "database": {
        "host": "db.company.com",
        "admin_email": "[e-mail]"
    },
    "api_keys": {
        "stripe": "sk_live_abcd1234...",
        "support_email": "[e-mail]"
    }
}

db = DoubleTake(known_paths=['database.admin_email', 'api_keys.support_email'])
sanitized_config = db.mask_data([config])[0]

🔬 Performance & Testing

doubletake includes comprehensive tests with 100% coverage:

# Run tests
pipenv run test

# Run with coverage
pipenv run pytest --cov=doubletake tests/

Performance Benchmarks (10,000 records):

• JSONGrepper: ~0.1s (simple patterns)
• DictWalker: ~0.3s (with fake data generation)

🤝 Contributing

We welcome contributions! Please see our contributing guidelines for details.

# Development setup
git clone https://github.com/paulcruse3/doubletake.git
cd doubletake
pipenv install --dev
pipenv run test

📄 License

MIT License - see LICENSE file for details.

🔗 Links

• Documentation (coming soon)
• Issues
• Changelog
• Security Policy

---

Made with ❤️ for data privacy and security