update script

python/shell.py

@@ -80,7 +80,12 @@ class Shell:
     @staticmethod
     def reset_by_pkgname(config):
         pkgname = input("输入包名: ")
-        os.system("git log --grep %s"% pkgname)
+        command = "%s\n%s" \
+            % (
+                "cd %s" % config['root'],
+                "git log --grep %s"% pkgname
+            )
+        os.system(command)
         print(" ")
 
         commit_id = input("输入commit id: ")