Move validate_backtest_data and get_timeframe to histoyr

freqtrade/data/history.py

@@ -5,19 +5,21 @@ Includes:
 * load data for a pair (or a list of pairs) from disk
 * download data from exchange and store to disk
 """
+
 import logging
+import operator
+from datetime import datetime
 from pathlib import Path
-from typing import Optional, List, Dict, Tuple, Any
+from typing import Any, Dict, List, Optional, Tuple
 
 import arrow
 from pandas import DataFrame
 
-from freqtrade import misc, OperationalException
+from freqtrade import OperationalException, misc
 from freqtrade.arguments import TimeRange
 from freqtrade.data.converter import parse_ticker_dataframe
 from freqtrade.exchange import Exchange, timeframe_to_minutes
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -243,3 +245,39 @@ def download_pair_history(datadir: Optional[Path],
             f'Error: {e}'
         )
         return False
+
+
+def get_timeframe(data: Dict[str, DataFrame]) -> Tuple[arrow.Arrow, arrow.Arrow]:
+    """
+    Get the maximum timeframe for the given backtest data
+    :param data: dictionary with preprocessed backtesting data
+    :return: tuple containing min_date, max_date
+    """
+    timeframe = [
+        (arrow.get(frame['date'].min()), arrow.get(frame['date'].max()))
+        for frame in data.values()
+    ]
+    return min(timeframe, key=operator.itemgetter(0))[0], \
+        max(timeframe, key=operator.itemgetter(1))[1]
+
+
+def validate_backtest_data(data: Dict[str, DataFrame], min_date: datetime,
+                           max_date: datetime, ticker_interval_mins: int) -> bool:
+    """
+    Validates preprocessed backtesting data for missing values and shows warnings about it that.
+
+    :param data: dictionary with preprocessed backtesting data
+    :param min_date: start-date of the data
+    :param max_date: end-date of the data
+    :param ticker_interval_mins: ticker interval in minutes
+    """
+    # total difference in minutes / interval-minutes
+    expected_frames = int((max_date - min_date).total_seconds() // 60 // ticker_interval_mins)
+    found_missing = False
+    for pair, df in data.items():
+        dflen = len(df)
+        if dflen < expected_frames:
+            found_missing = True
+            logger.warning("%s has missing frames: expected %s, got %s, that's %s missing values",
+                           pair, expected_frames, dflen, expected_frames - dflen)
+    return found_missing