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xiaobaifupan/app/backend/features/screener/backtest.py
T

142 lines
6.1 KiB
Python

from __future__ import annotations
import statistics
from collections import defaultdict
from datetime import datetime
from typing import Any
from backend.data.numbers import finite_number as _number
from backend.features.screener.factors import FactorBuilder
from backend.features.screener.formula import FormulaEvaluator
from database import ReviewDatabase
class BacktestRunner:
def __init__(
self,
database: ReviewDatabase,
factor_builder: FactorBuilder,
formula_evaluator: FormulaEvaluator,
) -> None:
self.database = database
self.factor_builder = factor_builder
self.formula_evaluator = formula_evaluator
self._backtest_factor_cache: dict[tuple[str, int], list[dict[str, Any]]] = {}
def build_factors(
self, trade_date: str, history_days: int
) -> tuple[list[dict[str, Any]], str]:
return self.factor_builder.build_factors(
trade_date, history_days=history_days
)
def apply_formula(
self, rows: list[dict[str, Any]], formula: dict[str, Any], regime: str
) -> list[dict[str, Any]]:
return self.formula_evaluator.apply_formula(rows, formula, regime)
def backtest(self, trade_date: str, formula: dict[str, Any]) -> dict[str, Any]:
meta = formula.get("meta") or {}
history_days = max(21, min(260, int(meta.get("history_days") or 80)))
holding_days = max(1, min(30, int(meta.get("backtest_days") or 3)))
take_profit = max(0.5, min(50.0, float(meta.get("take_profit") or 3)))
stop_loss = min(-0.5, max(-50.0, float(meta.get("stop_loss") or -3)))
dates = self.database.factor_dates(trade_date, history_days + holding_days + 20)
eligible_dates = dates[:-holding_days] if len(dates) > holding_days else []
frequency = str(meta.get("frequency") or "每日")
if "月" in frequency:
grouped = {}
for value in eligible_dates:
grouped[value[:6]] = value
evaluation_dates = list(grouped.values())[-8:]
elif "双周" in frequency:
weekly_dates = []
grouped = {}
for value in eligible_dates:
parsed = datetime.strptime(value, "%Y%m%d")
grouped[parsed.strftime("%G-%V")] = value
weekly_dates = list(grouped.values())
evaluation_dates = weekly_dates[-16::2][-8:]
elif "周" in frequency:
grouped = {}
for value in eligible_dates:
parsed = datetime.strptime(value, "%Y%m%d")
grouped[parsed.strftime("%G-%V")] = value
evaluation_dates = list(grouped.values())[-8:]
else:
evaluation_dates = eligible_dates[-8:]
wins = 0
losses = 0
samples = 0
returns = []
drawdowns = []
all_data = self.database.load_factor_data(
trade_date, history_days + holding_days + 20
)
bars_by_code: dict[str, list[dict[str, Any]]] = defaultdict(list)
for row in all_data["bars"]:
bars_by_code[row["ts_code"]].append(row)
for bars in bars_by_code.values():
bars.sort(key=lambda item: item["trade_date"])
for current_date in evaluation_dates:
try:
cache_key = (current_date, history_days)
factors = self._backtest_factor_cache.get(cache_key)
if factors is None:
factors, _ = self.build_factors(
current_date, history_days=history_days
)
if len(self._backtest_factor_cache) >= 64:
self._backtest_factor_cache.pop(
next(iter(self._backtest_factor_cache))
)
self._backtest_factor_cache[cache_key] = factors
except ValueError:
continue
selected = self.apply_formula(factors, {**formula, "limit": min(10, formula["limit"])}, "backtest")
for candidate in selected:
bars = bars_by_code.get(candidate["ts_code"], [])
index = next((i for i, row in enumerate(bars) if row["trade_date"] == current_date), -1)
future = bars[index + 1:index + 1 + holding_days] if index >= 0 else []
if len(future) < holding_days:
continue
entry = candidate["price"]
won = False
lost = False
for day in future:
low_return = (_number(day["low"]) / entry - 1) * 100
high_return = (_number(day["high"]) / entry - 1) * 100
if low_return <= stop_loss:
lost = True
break
if high_return >= take_profit:
won = True
break
if won:
wins += 1
elif lost:
losses += 1
samples += 1
returns.append((_number(future[-1]["close"]) / entry - 1) * 100)
drawdowns.append(min((_number(day["low"]) / entry - 1) * 100 for day in future))
return {
"samples": samples,
"wins": wins,
"losses": losses,
"win_rate": round(wins / samples * 100, 1) if samples else 0,
"average_3d_return": round(statistics.fmean(returns), 2) if returns else 0,
"average_holding_return": round(statistics.fmean(returns), 2) if returns else 0,
"average_drawdown": round(statistics.fmean(drawdowns), 2) if drawdowns else 0,
"evaluation_days": len(evaluation_dates),
"frequency": frequency,
"holding_days": holding_days,
"take_profit": take_profit,
"stop_loss": stop_loss,
"definition": (
f"收盘后选股,未来{holding_days}日先触及+{take_profit:g}%且未先触及"
f"{stop_loss:g}%计为成功;同日双触发按失败处理。"
),
"approximate": True,
}