pryscraper/quality.py
cryptorugmunch 8d25702eca chore(license): re-license to dual MIT (core) + BSL 1.1 (stealth)
Squashed from chore/license-relicense. Full message preserved in the
original branch commit bb77eb5. See ADR-0002 for the decision rationale.

Refs: ADR-0002, commit bb77eb5
2026-07-02 19:59:18 +02:00

403 lines
13 KiB
Python

"""Pry — Data Quality SLA Dashboard.
Per-extraction quality metrics, anomaly detection, freshness tracking."""
# SPDX-License-Identifier: MIT
# Copyright (c) 2026 Rug Munch Media LLC
#
# Part of Pry — https://git.rugmunch.io/RugMunchMedia/pryscraper
# Licensed under MIT. See LICENSE.
import difflib
import hashlib
import json
import logging
import os
import time
from contextlib import suppress
from datetime import UTC, datetime
from pathlib import Path
from typing import Any
logger = logging.getLogger(__name__)
QUALITY_DIR = Path(os.path.expanduser("~/.pry/quality"))
QUALITY_DIR.mkdir(parents=True, exist_ok=True)
# ── Quality Metrics ──
def compute_completeness(
data: dict[str, Any] | list[Any], schema: dict[str, Any] | None = None
) -> dict[str, Any]:
"""Compute completeness metrics for extracted data.
Measures:
- Field presence: what % of expected fields have non-null values
- Record count: expected vs actual for list data
- Schema adherence: what % of fields match expected types
"""
if isinstance(data, list):
return _compute_list_completeness(data, schema)
return _compute_dict_completeness(data, schema)
def _compute_dict_completeness(
data: dict[str, Any], schema: dict[str, Any] | None = None
) -> dict[str, Any]:
"""Compute completeness for a single dict."""
if not data:
return {
"score": 0,
"total_fields": 0,
"filled_fields": 0,
"null_fields": 0,
"empty_fields": 0,
}
total = len(data)
filled = sum(1 for v in data.values() if v not in (None, "", [], {}))
nulls = sum(1 for v in data.values() if v is None)
empties = sum(1 for v in data.values() if v in ("", [], {}) and v is not None)
score = round(filled / total * 100, 1) if total > 0 else 0.0
return {
"score": score,
"total_fields": total,
"filled_fields": filled,
"null_fields": nulls,
"empty_fields": empties,
}
def _compute_list_completeness(
data: list[Any], schema: dict[str, Any] | None = None
) -> dict[str, Any]:
"""Compute completeness for a list of records."""
if not data:
return {"score": 0, "record_count": 0, "avg_record_score": 0}
record_scores = []
total_possible = 0
total_filled = 0
for record in data:
if isinstance(record, dict):
result = _compute_dict_completeness(record, schema)
record_scores.append(result["score"])
total_possible += result["total_fields"]
total_filled += result["filled_fields"]
avg_record = round(sum(record_scores) / len(record_scores), 1) if record_scores else 0.0
overall = round(total_filled / total_possible * 100, 1) if total_possible > 0 else 0.0
return {
"score": overall,
"record_count": len(data),
"avg_record_score": avg_record,
"min_record_score": min(record_scores) if record_scores else 0,
"max_record_score": max(record_scores) if record_scores else 0,
}
def compute_schema_adherence(
data: dict[str, Any] | list[dict[str, Any]],
expected_types: dict[str, type],
) -> dict[str, Any]:
"""Check if fields match expected types."""
records = data if isinstance(data, list) else [data]
field_issues: dict[str, int] = {}
total_checks = 0
type_mismatches = 0
for record in records:
if isinstance(record, dict):
for field, expected_type in expected_types.items():
total_checks += 1
value = record.get(field)
if value is not None and not isinstance(value, expected_type):
type_mismatches += 1
field_issues[field] = field_issues.get(field, 0) + 1
return {
"score": round((total_checks - type_mismatches) / total_checks * 100, 1)
if total_checks > 0
else 100.0,
"total_checks": total_checks,
"type_mismatches": type_mismatches,
"field_issues": field_issues,
}
def compute_null_rate(data: dict[str, Any] | list[dict[str, Any]]) -> dict[str, Any]:
"""Compute null/empty rate per field."""
records = data if isinstance(data, list) else [data]
field_stats: dict[str, dict[str, Any]] = {}
for record in records:
if isinstance(record, dict):
for key, value in record.items():
if key not in field_stats:
field_stats[key] = {"total": 0, "null": 0, "empty": 0}
field_stats[key]["total"] += 1
if value is None:
field_stats[key]["null"] += 1
elif value in ("", [], {}):
field_stats[key]["empty"] += 1
return {
field: {
"null_rate": round(stats["null"] / stats["total"] * 100, 1),
"empty_rate": round(stats["empty"] / stats["total"] * 100, 1),
"total": stats["total"],
}
for field, stats in field_stats.items()
}
def compute_freshness(data: dict[str, Any], max_age_seconds: int = 3600) -> dict[str, Any]:
"""Check data freshness against expected age."""
now = time.time()
timestamps = []
# Look for timestamp fields
for key in ["timestamp", "checked_at", "cached_at", "scraped_at", "created_at", "updated_at"]:
val = data.get(key)
if val:
timestamps.append(val)
if not timestamps:
return {
"fresh": True,
"age_seconds": None,
"note": "No timestamp field found in data — cannot verify freshness",
}
# Try to parse the first timestamp
ts = timestamps[0]
if isinstance(ts, (int, float)):
age = now - ts
elif isinstance(ts, str):
try:
dt = datetime.fromisoformat(ts)
age = now - dt.timestamp()
except (ValueError, TypeError):
return {
"fresh": True,
"age_seconds": None,
"note": f"Could not parse timestamp: {ts[:30]}",
}
else:
return {"fresh": True, "age_seconds": None, "note": "Timestamp in unknown format"}
return {
"fresh": age <= max_age_seconds,
"age_seconds": round(age),
"max_age_seconds": max_age_seconds,
"note": f"Data is {_format_age(age)} old",
}
def _format_age(seconds: float) -> str:
if seconds < 60:
return f"{int(seconds)}s"
elif seconds < 3600:
return f"{int(seconds / 60)}m"
elif seconds < 86400:
return f"{int(seconds / 3600)}h"
return f"{int(seconds / 86400)}d"
def detect_anomalies(
current_data: dict[str, Any],
previous_data: dict[str, Any] | None = None,
z_score_threshold: float = 2.0,
) -> list[dict[str, Any]]:
"""Detect anomalies in extracted data compared to previous runs.
Flags:
- Missing fields (field present before, absent now)
- New fields (field absent before, present now)
- Value type changes
- Large value swings (for numeric fields)
- Empty results when previous had data
"""
anomalies: list[dict[str, Any]] = []
if previous_data is None:
return []
# Check for empty results
if not current_data and previous_data:
anomalies.append(
{
"type": "empty_result",
"severity": "critical",
"field": "*",
"message": "Extraction returned empty — previous run had data",
}
)
return anomalies
if not isinstance(current_data, dict) or not isinstance(previous_data, dict):
return anomalies
prev_keys = set(previous_data.keys())
curr_keys = set(current_data.keys())
# Missing fields
missing = prev_keys - curr_keys
for field in missing:
anomalies.append(
{
"type": "missing_field",
"severity": "high",
"field": field,
"message": f"Field '{field}' was present in previous extraction but is now missing",
}
)
# New fields
new_fields = curr_keys - prev_keys
for field in new_fields:
anomalies.append(
{
"type": "new_field",
"severity": "info",
"field": field,
"message": f"New field '{field}' appeared",
}
)
# Value changes for common fields
common = prev_keys & curr_keys
for field in common:
prev_val = previous_data[field]
curr_val = current_data[field]
# Type change
if prev_val is not None and curr_val is not None and type(prev_val) is not type(curr_val):
anomalies.append(
{
"type": "type_change",
"severity": "high",
"field": field,
"message": f"Field '{field}' changed type: {type(prev_val).__name__}{type(curr_val).__name__}",
"previous_type": type(prev_val).__name__,
"current_type": type(curr_val).__name__,
}
)
continue
# Numeric swing
if (
isinstance(prev_val, (int, float))
and isinstance(curr_val, (int, float))
and prev_val != 0
):
z_score = abs((curr_val - prev_val) / max(abs(prev_val), 0.01))
if z_score > z_score_threshold:
pct = ((curr_val - prev_val) / abs(prev_val)) * 100
anomalies.append(
{
"type": "value_swing",
"severity": "high" if abs(pct) > 50 else "medium",
"field": field,
"message": f"Field '{field}' changed by {pct:+.1f}% ({prev_val}{curr_val})",
"previous_value": prev_val,
"current_value": curr_val,
"change_pct": round(pct, 1),
}
)
# Text content change
if (
isinstance(prev_val, str)
and isinstance(curr_val, str)
and prev_val != curr_val
and len(prev_val) > 20
):
ratio = difflib.SequenceMatcher(None, prev_val, curr_val).ratio()
if ratio < 0.5:
anomalies.append(
{
"type": "content_drift",
"severity": "medium",
"field": field,
"message": f"Field '{field}' content changed significantly ({round(ratio * 100)}% similarity)",
"similarity": round(ratio, 3),
}
)
return anomalies
async def run_quality_check(
url: str,
data: dict[str, Any],
schema: dict[str, Any] | None = None,
expected_types: dict[str, type] | None = None,
max_age_seconds: int = 3600,
) -> dict[str, Any]:
"""Run full quality check on extracted data.
Returns completeness, schema adherence, freshness, anomalies.
"""
# Load previous data for comparison
url_hash = hashlib.sha256(url.encode()).hexdigest()[:16]
history_path = QUALITY_DIR / f"{url_hash}.json"
previous_data: dict[str, Any] | None = None
if history_path.exists():
try:
prev = json.loads(history_path.read_text())
previous_data = prev.get("data")
except (json.JSONDecodeError, OSError):
pass
# Compute metrics
completeness = compute_completeness(data, schema)
freshness = compute_freshness(data, max_age_seconds)
anomalies = detect_anomalies(data, previous_data)
null_rate: dict[str, Any] = {}
schema_adherence: dict[str, Any] = {
"score": 100.0,
"total_checks": 0,
"type_mismatches": 0,
"field_issues": {},
}
if isinstance(data, dict):
null_rate = compute_null_rate(data)
if expected_types:
schema_adherence = compute_schema_adherence(data, expected_types)
# Save current data for future comparison
with suppress(OSError):
history_path.write_text(
json.dumps({"url": url, "data": data, "checked_at": datetime.now(UTC).isoformat()})
)
# Compute overall quality score (weighted average)
quality_score = round(
completeness.get("score", 0) * 0.4
+ (100 - len(anomalies) * 10) * 0.3
+ schema_adherence.get("score", 100) * 0.2
+ (100 if freshness.get("fresh") else 50) * 0.1,
1,
)
quality_score = max(0, min(100, quality_score))
return {
"url": url,
"quality_score": quality_score,
"completeness": completeness,
"schema_adherence": schema_adherence,
"freshness": freshness,
"null_rates": null_rate,
"anomalies": anomalies,
"anomaly_count": len(anomalies),
"critical_anomalies": sum(1 for a in anomalies if a["severity"] == "critical"),
"has_previous_data": previous_data is not None,
"checked_at": datetime.now(UTC).isoformat(),
}