From 374648c21aa1212c17af0e6299bb13474da3e49f Mon Sep 17 00:00:00 2001
From: mitama <33838461+nigimitama@users.noreply.github.com>
Date: Sun, 10 Nov 2019 02:58:14 +0900
Subject: [PATCH] Add better error message for invalid feature names (#5024)

---
 python-package/xgboost/core.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python-package/xgboost/core.py b/python-package/xgboost/core.py
index 8387fcf98..444d36ece 100644
--- a/python-package/xgboost/core.py
+++ b/python-package/xgboost/core.py
@@ -999,7 +999,7 @@ class DMatrix(object):
             if not all(isinstance(f, STRING_TYPES) and
                        not any(x in f for x in set(('[', ']', '<')))
                        for f in feature_names):
-                raise ValueError('feature_names may not contain [, ] or <')
+                raise ValueError('feature_names must be string, and may not contain [, ] or <')
         else:
             # reset feature_types also
             self.feature_types = None