diff --git a/examples/CoinapiDataService/dataService.py b/examples/CoinapiDataService/dataService.py
index 50279b75..21e52138 100644
--- a/examples/CoinapiDataService/dataService.py
+++ b/examples/CoinapiDataService/dataService.py
@@ -51,8 +51,8 @@ def downMinuteBarBySymbol(symbol, period, start, end):
     """下载某一合约的分钟线数据"""
     startTime = time.time()
     
-    cl = db[symbol]                                                 # 集合
-    cl.ensure_index([('datetime', ASCENDING)], unique=True)         # 添加索引
+    cl = db[symbol]                                                 
+    cl.ensure_index([('datetime', ASCENDING)], unique=True)         
     
     startDt = datetime.datetime.strptime(start, '%Y%m%d')
     endDt = datetime.datetime.strptime(end, '%Y%m%d')
diff --git a/examples/CryptoTrader/run.py b/examples/CryptoTrader/run.py
index ab6bdb77..240b8272 100644
--- a/examples/CryptoTrader/run.py
+++ b/examples/CryptoTrader/run.py
@@ -9,10 +9,6 @@ import sys
 reload(sys)
 sys.setdefaultencoding('utf8')
 
-# 判断操作系统
-import platform
-system = platform.system()
-
 # vn.trader模块
 from vnpy.event import EventEngine
 from vnpy.trader.vtEngine import MainEngine