diff --git a/qlib/contrib/backtest/account.py b/qlib/contrib/backtest/account.py
index b2e307fe5..a614f08b6 100644
--- a/qlib/contrib/backtest/account.py
+++ b/qlib/contrib/backtest/account.py
@@ -167,4 +167,3 @@ class Account:
     def save_account(self, account_path):
         self.current.save_position(account_path / "position.xlsx", self.last_trade_date)
         self.report.save_report(account_path / "report.csv")
-
diff --git a/qlib/contrib/backtest/exchange.py b/qlib/contrib/backtest/exchange.py
index 369b3aef3..178950eeb 100644
--- a/qlib/contrib/backtest/exchange.py
+++ b/qlib/contrib/backtest/exchange.py
@@ -423,4 +423,3 @@ class Exchange:
             raise NotImplementedError("order type {} error".format(order.type))
 
         return trade_val, trade_cost
-