Small style fixes and adjusted tests

freqtrade/data/history.py

@@ -147,7 +147,7 @@ def load_pair_history(pair: str,
     """
 
     timerange_startup = deepcopy(timerange)
-    if startup_candles:
+    if startup_candles and timerange_startup:
         logger.info('Using indicator startup period: %s ...', startup_candles)
         timerange_startup.subtract_start(timeframe_to_seconds(ticker_interval) * startup_candles)
 

freqtrade/exchange/exchange.py

@@ -447,6 +447,7 @@ class Exchange:
     def validate_required_startup_candles(self, startup_candles) -> None:
         """
         Checks if required startup_candles is more than ohlcv_candle_limit.
+        Requires a grace-period of 5 candles - so a startup-period up to 494 is allowed by default.
         """
         if startup_candles + 5 > self._ft_has['ohlcv_candle_limit']:
             raise OperationalException(

freqtrade/optimize/hyperopt.py

@@ -22,8 +22,7 @@ from pandas import DataFrame
 from skopt import Optimizer
 from skopt.space import Dimension
 
-from freqtrade.configuration import TimeRange
-from freqtrade.data.history import load_data, get_timeframe, trim_dataframe
+from freqtrade.data.history import get_timeframe, trim_dataframe
 from freqtrade.misc import round_dict
 from freqtrade.optimize.backtesting import Backtesting
 # Import IHyperOpt and IHyperOptLoss to allow unpickling classes from these modules

freqtrade/strategy/interface.py

@@ -424,7 +424,7 @@ class IStrategy(ABC):
     def tickerdata_to_dataframe(self, tickerdata: Dict[str, List]) -> Dict[str, DataFrame]:
         """
         Creates a dataframe and populates indicators for given ticker data
-        Used by optimize operations only, not  during dry / live runs.
+        Used by optimize operations only, not during dry / live runs.
         """
         return {pair: self.advise_indicators(pair_data, {'pair': pair})
                 for pair, pair_data in tickerdata.items()}