Files
xiaobaifupan/app/backend/data/quality.py
T

203 lines
7.2 KiB
Python

from __future__ import annotations
import json
from dataclasses import dataclass
from datetime import date, datetime, time, timedelta, timezone
from pathlib import Path
from typing import Any
from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
from backend.bootstrap.config import APP_DIR
from backend.data.contracts import DataUsage
from backend.data.policy import DataPolicyError, DataSourcePolicy
class DataQualityError(RuntimeError):
pass
def market_timezone(name: str = "Asia/Shanghai"):
try:
return ZoneInfo(name)
except ZoneInfoNotFoundError:
if name != "Asia/Shanghai":
raise
return timezone(timedelta(hours=8), name)
@dataclass(frozen=True)
class QualityEvidence:
dataset_id: str
provider_id: str
data_time: str | datetime
observed_at: str | datetime
actual_count: int | None = None
expected_count: int | None = None
units: dict[str, str] | None = None
adjustment: str = ""
available_at: str | datetime | None = None
@dataclass(frozen=True)
class QualityReport:
accepted: bool
dataset_id: str
provider_id: str
usage: DataUsage
coverage_ratio: float | None
age_seconds: float
issues: tuple[str, ...]
def as_dict(self) -> dict[str, Any]:
return {
"accepted": self.accepted,
"dataset_id": self.dataset_id,
"provider_id": self.provider_id,
"usage": self.usage,
"coverage_ratio": self.coverage_ratio,
"age_seconds": round(self.age_seconds, 3),
"issues": list(self.issues),
}
class DataQualityGate:
def __init__(
self,
source_policy: DataSourcePolicy,
payload: dict[str, Any],
) -> None:
self.source_policy = source_policy
self.timezone = market_timezone(
str(payload.get("timezone") or "Asia/Shanghai")
)
self.defaults = dict(payload.get("defaults") or {})
self.unit_profiles = dict(payload.get("unit_profiles") or {})
self.rules = dict(payload.get("datasets") or {})
@classmethod
def load(
cls,
source_policy: DataSourcePolicy,
path: Path | None = None,
) -> "DataQualityGate":
config_path = path or APP_DIR / "config" / "data-quality.config.json"
payload = json.loads(config_path.read_text(encoding="utf-8"))
return cls(source_policy, payload)
def evaluate(
self,
evidence: QualityEvidence,
usage: DataUsage,
as_of: str | datetime | None = None,
) -> QualityReport:
issues: list[str] = []
try:
self.source_policy.assert_allowed(
evidence.dataset_id, evidence.provider_id, usage
)
except DataPolicyError as exc:
issues.append(str(exc))
rule = self.rules.get(evidence.dataset_id)
if rule is None:
issues.append(f"Missing quality rule: {evidence.dataset_id}")
rule = {}
if rule.get("blocked"):
issues.append(f"Dataset quality is blocked: {evidence.dataset_id}")
reference = self._datetime(as_of or datetime.now(self.timezone))
data_time = self._datetime(evidence.data_time)
observed_at = self._datetime(evidence.observed_at)
tolerance = float(
(self.defaults.get(usage) or {}).get("future_tolerance_seconds") or 0
)
if data_time > reference + timedelta(seconds=tolerance):
issues.append("Data time is later than the evaluation time")
if observed_at > reference + timedelta(seconds=tolerance):
issues.append("Observation time is later than the evaluation time")
if observed_at < data_time:
issues.append("Observation time precedes data time")
age_seconds = max(0.0, (reference - data_time).total_seconds())
freshness = rule.get("freshness_seconds")
if freshness is not None and age_seconds > float(freshness):
issues.append(
f"Data is stale: {age_seconds:.1f}s exceeds {float(freshness):.1f}s"
)
coverage_ratio: float | None = None
if evidence.expected_count is not None:
if evidence.expected_count <= 0:
issues.append("Expected count must be positive")
elif evidence.actual_count is None or evidence.actual_count < 0:
issues.append("Actual count is missing or invalid")
else:
coverage_ratio = min(1.0, evidence.actual_count / evidence.expected_count)
minimum = float(rule.get("min_coverage_ratio") or 0)
if coverage_ratio < minimum:
issues.append(
f"Coverage {coverage_ratio:.3f} is below {minimum:.3f}"
)
required_adjustment = str(rule.get("adjustment") or "")
if required_adjustment and evidence.adjustment != required_adjustment:
issues.append(
f"Adjustment {evidence.adjustment or 'missing'} does not match {required_adjustment}"
)
profile_id = str(rule.get("unit_profile") or "none")
required_units = dict(self.unit_profiles.get(profile_id) or {})
supplied_units = evidence.units or {}
for field, expected_unit in required_units.items():
actual_unit = supplied_units.get(field)
if actual_unit != expected_unit:
issues.append(
f"Unit for {field} is {actual_unit or 'missing'}, expected {expected_unit}"
)
if rule.get("point_in_time") == "announcement_date" and usage == "calculation":
if evidence.available_at is None:
issues.append("Point-in-time availability is missing")
elif self._datetime(evidence.available_at) > reference:
issues.append("Point-in-time data was not available at evaluation time")
return QualityReport(
accepted=not issues,
dataset_id=evidence.dataset_id,
provider_id=evidence.provider_id,
usage=usage,
coverage_ratio=coverage_ratio,
age_seconds=age_seconds,
issues=tuple(issues),
)
def require(
self,
evidence: QualityEvidence,
usage: DataUsage,
as_of: str | datetime | None = None,
) -> QualityReport:
report = self.evaluate(evidence, usage, as_of)
if not report.accepted:
raise DataQualityError("; ".join(report.issues))
return report
def _datetime(self, value: str | datetime) -> datetime:
if isinstance(value, datetime):
parsed = value
else:
text = str(value or "").strip()
if not text:
raise DataQualityError("Quality evidence timestamp is missing")
try:
parsed = datetime.fromisoformat(text)
except ValueError:
try:
day = date.fromisoformat(text)
except ValueError as exc:
raise DataQualityError(f"Invalid quality timestamp: {text}") from exc
parsed = datetime.combine(day, time.min)
if parsed.tzinfo is None:
return parsed.replace(tzinfo=self.timezone)
return parsed.astimezone(self.timezone)