From 62b6f1f926ecd4833aa446cdcaf3e987babd2fa1 Mon Sep 17 00:00:00 2001
From: Jiaming Yuan <jm.yuan@outlook.com>
Date: Thu, 16 Mar 2023 20:26:31 +0800
Subject: [PATCH] reduce memory usage.

---
 python-package/xgboost/sklearn.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/python-package/xgboost/sklearn.py b/python-package/xgboost/sklearn.py
index 75433ca5b320..8da0387cbb06 100644
--- a/python-package/xgboost/sklearn.py
+++ b/python-package/xgboost/sklearn.py
@@ -1824,8 +1824,12 @@ def _get_qid(
                 "`fit` method. Please remove one of them."
             )
         q_x = X.qid
-        X = X.drop("qid", axis=1)
-        return X, q_x
+        d = {}
+        columns = X.columns.difference(["qid"])
+        for c in columns:
+            d[c] = X.loc[:, c]
+        X_n = type(X)(d)
+        return X_n, q_x
     return X, qid