diff --git a/main.py b/main.py
index 93cc09c..90c4598 100644
--- a/main.py
+++ b/main.py
@@ -133,6 +133,7 @@ class GMCLCore(object):
         except:
             return "Error:Wrong parameter for game memory."
     def Download(self,DownloadFrom,DownloadTo,ThreadNum=3):
+        '''Multi-Thread download function'''
         if(DownloadFrom=="" or DownloadTo==""):
             return "Error:Wrong online address or local address for download."
         else:
@@ -159,6 +160,5 @@ class GMCLCore(object):
                     t = MultiThreadDownload(url,start,end,fd,self.__UserAgent)
                     t.start()
                     mtd_list.append(t)
-
                 for i in mtd_list:
                     i.join()