convert exportfilename to Path when config parsing

freqtrade/configuration/configuration.py

@@ -196,6 +196,7 @@ class Configuration:
         if self.args.get('exportfilename'):
             self._args_to_config(config, argname='exportfilename',
                                  logstring='Storing backtest results to {} ...')
+            config['exportfilename'] = Path(config['exportfilename'])
         else:
             config['exportfilename'] = (config['user_data_dir']
                                         / 'backtest_results/backtest-result.json')

freqtrade/data/btanalysis.py

@@ -129,16 +129,20 @@ def load_trades_from_db(db_url: str) -> pd.DataFrame:
     return trades
 
 
-def load_trades(source: str, db_url: str, exportfilename: str) -> pd.DataFrame:
+def load_trades(source: str, db_url: str, exportfilename: Path) -> pd.DataFrame:
     """
     Based on configuration option "trade_source":
     * loads data from DB (using `db_url`)
     * loads data from backtestfile (using `exportfilename`)
+    :param source: "DB" or "file" - specify source to load from
+    :param db_url: sqlalchemy formatted url to a database
+    :param exportfilename: Json file generated by backtesting
+    :return: DataFrame containing trades
     """
     if source == "DB":
         return load_trades_from_db(db_url)
     elif source == "file":
-        return load_backtest_data(Path(exportfilename))
+        return load_backtest_data(exportfilename)
 
 
 def extract_trades_of_period(dataframe: pd.DataFrame, trades: pd.DataFrame) -> pd.DataFrame:

freqtrade/optimize/backtesting.py

@@ -421,7 +421,7 @@ class Backtesting:
         for strategy, results in all_results.items():
 
             if self.config.get('export', False):
-                self._store_backtest_result(Path(self.config['exportfilename']), results,
+                self._store_backtest_result(self.config['exportfilename'], results,
                                             strategy if len(self.strategylist) > 1 else None)
 
             print(f"Result for strategy {strategy}")