feat: Enhanced PII detection with GDPR compliance and Nordic recognizers

This commit is contained in:
2025-11-07 20:06:12 +05:30
parent 83ecfc510e
commit fd3f924cc6
5 changed files with 122 additions and 18 deletions

View File

@@ -8,6 +8,7 @@ import pandas as pd
import numpy as np
import hashlib
import json
import re
from datetime import datetime
from typing import Dict, List, Tuple, Optional, Any
from collections import defaultdict
@@ -375,10 +376,14 @@ class DataCleaner:
) -> Dict[str, List[Dict]]:
"""
Detect PII at column and cell level (GPU-accelerated when available)
With intelligent filtering for false positives
Returns:
Dictionary mapping column names to list of detected entities
"""
import re
from data_cleaning.config import COLUMN_CONTEXT_FILTERS, EXCLUSION_PATTERNS
pii_detections = defaultdict(list)
# Determine which columns to scan
@@ -417,26 +422,69 @@ class DataCleaner:
)
if results:
# Aggregate by entity type
entity_summary = defaultdict(lambda: {'count': 0, 'scores': []})
# Aggregate by entity type with filtering
entity_summary = defaultdict(lambda: {'count': 0, 'scores': [], 'filtered': 0})
filtered_reasons = []
for result in results:
entity_summary[result.entity_type]['count'] += 1
entity_summary[result.entity_type]['scores'].append(result.score)
entity_type = result.entity_type
# Extract detected text from original string using start/end positions
detected_text = combined_text[result.start:result.end]
# ✅ FILTER 1: Column Context Filtering
# Skip if entity type should be ignored based on column name
context_filtered = False
for pattern, ignored_entities in COLUMN_CONTEXT_FILTERS.items():
if re.search(pattern, column.lower()) and entity_type in ignored_entities:
context_filtered = True
entity_summary[entity_type]['filtered'] += 1
if f"column context ({pattern})" not in filtered_reasons:
filtered_reasons.append(f"column context ({pattern})")
break
if context_filtered:
continue
# ✅ FILTER 2: Value Pattern Exclusions
# Skip if detected value matches exclusion patterns
pattern_filtered = False
if entity_type in EXCLUSION_PATTERNS:
for exclusion_pattern in EXCLUSION_PATTERNS[entity_type]:
if re.match(exclusion_pattern, detected_text, re.IGNORECASE):
pattern_filtered = True
entity_summary[entity_type]['filtered'] += 1
if f"value pattern ({exclusion_pattern[:20]}...)" not in filtered_reasons:
filtered_reasons.append(f"value pattern")
break
if pattern_filtered:
continue
# ✅ Not filtered - count as valid detection
entity_summary[entity_type]['count'] += 1
entity_summary[entity_type]['scores'].append(result.score)
# Store detection results
# Store detection results (only non-filtered)
detected_types = []
for entity_type, info in entity_summary.items():
avg_confidence = np.mean(info['scores'])
pii_detections[column].append({
'entity_type': entity_type,
'count': info['count'],
'avg_confidence': avg_confidence,
'max_confidence': max(info['scores']),
'min_confidence': min(info['scores'])
})
if info['count'] > 0: # Only include if we have valid (non-filtered) detections
avg_confidence = np.mean(info['scores'])
pii_detections[column].append({
'entity_type': entity_type,
'count': info['count'],
'avg_confidence': avg_confidence,
'max_confidence': max(info['scores']),
'min_confidence': min(info['scores'])
})
detected_types.append(entity_type)
detected_types = [d['entity_type'] for d in pii_detections[column]]
print(f"✓ Found: {', '.join(detected_types)}")
if detected_types:
print(f"✓ Found: {', '.join(detected_types)}")
elif any(info['filtered'] > 0 for info in entity_summary.values()):
total_filtered = sum(info['filtered'] for info in entity_summary.values())
print(f"(filtered {total_filtered} false positives: {', '.join(filtered_reasons[:2])})")
else:
print("(no PII)")
else:
print("(no PII)")

View File

@@ -126,9 +126,63 @@ GDPR_COMPLIANCE = {
# Presidio Analyzer Settings
PRESIDIO_CONFIG = {
'language': 'en',
'score_threshold': 0.5, # Minimum confidence to report
'score_threshold': 0.6, # Minimum confidence to report (raised from 0.5 to reduce false positives)
'entities': None, # None = detect all, or specify list like ['EMAIL_ADDRESS', 'PHONE_NUMBER']
'allow_list': [], # Terms to ignore (e.g., company names that look like PII)
'allow_list': ['l1', 'l2', 'L1', 'L2', 'NA', 'N/A', 'null', 'none'], # Common non-PII values
}
# Column Context Filters - Ignore specific entity types based on column name patterns
# This prevents false positives when column names provide context
COLUMN_CONTEXT_FILTERS = {
# Column name pattern (regex) -> List of entity types to IGNORE in that column
r'.*credit.*': ['US_DRIVER_LICENSE', 'US_PASSPORT', 'PERSON'],
r'.*rating.*': ['US_DRIVER_LICENSE', 'US_PASSPORT'],
r'.*level.*': ['US_DRIVER_LICENSE', 'US_PASSPORT'],
r'.*score.*': ['US_DRIVER_LICENSE', 'US_PASSPORT', 'PERSON'],
r'.*category.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*status.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*type.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*grade.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*class.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*rank.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*tier.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*segment.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*group.*': ['US_DRIVER_LICENSE', 'PERSON'],
r'.*code.*': ['PERSON'], # Codes are rarely names
r'.*id$': ['PERSON'], # IDs ending in 'id' are rarely names
r'.*_id$': ['PERSON'], # Same for underscore_id
}
# Value Pattern Exclusions - Ignore values matching these patterns for specific entity types
# This catches false positives based on the actual detected value format
EXCLUSION_PATTERNS = {
'US_DRIVER_LICENSE': [
r'^[a-zA-Z]\d{1,2}$', # Single letter + 1-2 digits (e.g., l1, l2, A1, B12)
r'^[a-zA-Z]{1,2}$', # 1-2 letters only (e.g., A, AB)
r'^level\s*\d+$', # "level 1", "level 2", etc.
r'^tier\s*\d+$', # "tier 1", "tier 2", etc.
r'^grade\s*[a-zA-Z]$', # "grade A", "grade B", etc.
],
'US_PASSPORT': [
r'^[a-zA-Z]\d{1,2}$', # Single letter + 1-2 digits
r'^[a-zA-Z]{1,2}$', # 1-2 letters only
],
'PERSON': [
r'^(admin|user|guest|system|default|test|demo)$', # Generic usernames
r'^[a-zA-Z]\d*$', # Single letter with optional numbers (A, A1, B2)
r'^(yes|no|true|false|y|n|t|f)$', # Boolean values
r'^(male|female|m|f|other)$', # Gender categories
r'^(low|medium|high|good|bad|excellent|poor)$', # Rating values
],
'EMAIL_ADDRESS': [
r'^(test|demo|example|sample)@', # Test emails
r'@(test|demo|example|sample)\.', # Test domains
],
'PHONE_NUMBER': [
r'^(000|111|222|333|444|555|666|777|888|999)[-\s]', # Fake phone patterns
r'^1{6,}$', # All 1s
r'^0{6,}$', # All 0s
],
}
# Custom Recognizers (domain-specific patterns)