From 903de019a2ee4089eb1eec4573856cc5b3465004 Mon Sep 17 00:00:00 2001
From: Jeff Reback <jeff@reback.net>
Date: Tue, 11 Nov 2014 09:39:49 -0500
Subject: [PATCH] COMPAT: remove Index warnings from io/ga.py

---
 pandas/io/ga.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/io/ga.py b/pandas/io/ga.py
index f002994888932..57de5c6f5abb4 100644
--- a/pandas/io/ga.py
+++ b/pandas/io/ga.py
@@ -430,7 +430,7 @@ def _clean_index(index_dims, parse_dates):
     to_remove = pd.Index(set(to_remove))
     to_add = pd.Index(set(to_add))
 
-    return index_dims - to_remove + to_add
+    return index_dims.difference(to_remove).union(to_add)
 
 
 def _get_col_names(header_info):